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serval-dna/http_server.c
Andrew Bettison e05d70b1a5 Fix wild assertion in HTTP server 
In the _reserve() function, an assertion compared pointers which it assumed
both pointed within the heap, or in fact within the same buffer.  However, if
one pointer pointed into the stack, then the assertion would incorrectly fail
if the stack were located below the heap in address space.  That never happens
in a normal Linux process, but _can_ happen in a thread, since thread stacks
may be allocated on the heap.

Solution was to re-order the steps in which _reserve() overwrites the buffer,
making the assertion irrelevant.
2014-09-11 16:11:23 +09:30

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/*
Serval DNA - HTTP Server
Copyright (C) 2013 Serval Project Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <assert.h>
#include <inttypes.h>
#include <time.h>
#include "serval_types.h"
#include "http_server.h"
#include "sighandlers.h"
#include "conf.h"
#include "log.h"
#include "str.h"
#include "strbuf.h"
#include "strbuf_helpers.h"
#include "net.h"
#include "mem.h"
#define BOUNDARY_STRING_MAXLEN 70 // legislated limit from RFC-1341
/* The (struct http_request).verb field points to one of these static strings, so that a simple
* equality test can be used, eg, (r->verb == HTTP_VERB_GET) instead of a strcmp().
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
const char HTTP_VERB_GET[] = "GET";
const char HTTP_VERB_POST[] = "POST";
const char HTTP_VERB_PUT[] = "PUT";
const char HTTP_VERB_HEAD[] = "HEAD";
const char HTTP_VERB_DELETE[] = "DELETE";
const char HTTP_VERB_TRACE[] = "TRACE";
const char HTTP_VERB_OPTIONS[] = "OPTIONS";
const char HTTP_VERB_CONNECT[] = "CONNECT";
const char HTTP_VERB_PATCH[] = "PATCH";
static struct {
const char *word;
size_t wordlen;
} http_verbs[] = {
#define VERB_ENTRY(NAME) { HTTP_VERB_##NAME, sizeof HTTP_VERB_##NAME - 1 }
VERB_ENTRY(GET),
VERB_ENTRY(POST),
VERB_ENTRY(PUT),
VERB_ENTRY(HEAD),
VERB_ENTRY(DELETE),
VERB_ENTRY(TRACE),
VERB_ENTRY(OPTIONS),
VERB_ENTRY(CONNECT),
VERB_ENTRY(PATCH)
#undef VERB_ENTRY
};
const char CONTENT_TYPE_TEXT[] = "text/plain";
const char CONTENT_TYPE_HTML[] = "text/html";
const char CONTENT_TYPE_JSON[] = "application/json";
const char CONTENT_TYPE_BLOB[] = "application/octet-stream";
static struct profile_total http_server_stats = {
.name = "http_server_poll",
};
#define DEBUG_DUMP_PARSED(r) do { \
if (config.debug.http_server) \
DEBUGF("%s %s HTTP/%u.%u", r->verb ? r->verb : "NULL", alloca_str_toprint(r->path), r->version_major, r->version_minor);\
} while (0)
#define DEBUG_DUMP_PARSER(r) do { \
if (config.debug.http_server) \
DEBUGF("parsed %d %s cursor %d %s end %d remain %"PRIhttp_size_t, \
(int)(r->parsed - r->received), alloca_toprint(-1, r->parsed, r->cursor - r->parsed), \
(int)(r->cursor - r->received), alloca_toprint(50, r->cursor, r->end - r->cursor), \
(int)(r->end - r->received), \
r->request_content_remaining \
); \
} while (0)
static void http_server_poll(struct sched_ent *);
static void http_request_set_idle_timeout(struct http_request *r);
static int http_request_parse_verb(struct http_request *r);
static int http_request_parse_path(struct http_request *r);
static int http_request_parse_http_version(struct http_request *r);
static int http_request_start_parsing_headers(struct http_request *r);
static int http_request_parse_header(struct http_request *r);
static int http_request_start_body(struct http_request *r);
static int http_request_reject_content(struct http_request *r);
static int http_request_parse_body_form_data(struct http_request *r);
static void http_request_start_response(struct http_request *r);
void http_request_init(struct http_request *r, int sockfd)
{
assert(sockfd != -1);
r->request_header.content_length = CONTENT_LENGTH_UNKNOWN;
r->request_content_remaining = CONTENT_LENGTH_UNKNOWN;
r->response.header.content_length = CONTENT_LENGTH_UNKNOWN;
r->response.header.resource_length = CONTENT_LENGTH_UNKNOWN;
r->alarm.stats = &http_server_stats;
r->alarm.function = http_server_poll;
assert(r->idle_timeout >= 0);
if (r->idle_timeout == 0)
r->idle_timeout = 10000; // 10 seconds
r->alarm.poll.fd = sockfd;
r->alarm.poll.events = POLLIN;
r->phase = RECEIVE;
r->reserved = r->buffer;
// Put aside a few bytes for reserving strings, so that the path can be reserved ok.
r->received = r->end = r->parsed = r->cursor = r->buffer + 32;
r->parser = http_request_parse_verb;
watch(&r->alarm);
http_request_set_idle_timeout(r);
}
static void http_request_set_idle_timeout(struct http_request *r)
{
assert(r->phase == RECEIVE || r->phase == TRANSMIT);
r->alarm.alarm = gettime_ms() + r->idle_timeout;
r->alarm.deadline = r->alarm.alarm + 500;
unschedule(&r->alarm);
schedule(&r->alarm);
}
void http_request_free_response_buffer(struct http_request *r)
{
if (r->response_free_buffer) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Free response buffer of %zu bytes", r->response_buffer_size);
r->response_free_buffer(r->response_buffer);
r->response_free_buffer = NULL;
}
r->response_buffer = NULL;
r->response_buffer_size = 0;
}
int http_request_set_response_bufsize(struct http_request *r, size_t bufsiz)
{
// Don't allocate a new buffer if the existing one contains content.
assert(r->response_buffer_sent == r->response_buffer_length);
const char *const bufe = r->buffer + sizeof r->buffer;
assert(r->reserved < bufe);
size_t rbufsiz = bufe - r->reserved;
if (bufsiz <= rbufsiz) {
http_request_free_response_buffer(r);
r->response_buffer = (char *) r->reserved;
r->response_buffer_size = rbufsiz;
if (r->debug_flag && *r->debug_flag)
DEBUGF("Static response buffer %zu bytes", r->response_buffer_size);
return 0;
}
if (bufsiz != r->response_buffer_size) {
http_request_free_response_buffer(r);
if ((r->response_buffer = emalloc(bufsiz)) == NULL)
return -1;
r->response_free_buffer = free;
r->response_buffer_size = bufsiz;
if (r->debug_flag && *r->debug_flag)
DEBUGF("Allocated response buffer %zu bytes", r->response_buffer_size);
}
assert(r->response_buffer_size >= bufsiz);
assert(r->response_buffer != NULL);
return 0;
}
void http_request_finalise(struct http_request *r)
{
if (r->phase == DONE)
return;
assert(r->phase == RECEIVE || r->phase == TRANSMIT || r->phase == PAUSE);
unschedule(&r->alarm);
if (r->phase != PAUSE)
unwatch(&r->alarm);
close(r->alarm.poll.fd);
r->alarm.poll.fd = -1;
if (r->finalise)
r->finalise(r);
r->finalise = NULL;
http_request_free_response_buffer(r);
r->phase = DONE;
}
struct substring {
const char *start;
const char *end;
};
#define alloca_substring_toprint(sub) alloca_toprint(-1, (sub).start, (sub).end - (sub).start)
const struct substring substring_NULL = { NULL, NULL };
#if 0
static int _matches(struct substring str, const char *text)
{
return strlen(text) == str.end - str.start && memcmp(str.start, text, str.end - str.start) == 0;
}
#endif
static void write_pointer(unsigned char *mem, const void *v)
{
memcpy(mem, &v, sizeof(void*));
}
static void *read_pointer(const unsigned char *mem)
{
void *v;
memcpy(&v, mem, sizeof(void*));
return v;
}
/* Allocate space from the start of the request buffer to hold the given substring plus a
* terminating NUL. Enough bytes must have already been marked as parsed in order to make room,
* otherwise the reservation fails and returns 0. If successful, copies the substring plus a
* terminating NUL into the reserved space, places a pointer to the reserved area into '*resp', and
* returns 1.
*
* Keeps a copy to the pointer 'resp', so that when the reserved area is released, all pointers into
* it can be set to NULL automatically. This provides some safety: if the pointer is accidentally
* dereferenced after the release it will cause a SEGV instead of using a string that has been
* overwritten. It does not protect from using copies of '*resp', which of course will not be have
* been set to NULL by the release.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
static int _reserve(struct http_request *r, const char **resp, struct substring str)
{
// Reserved string pointer must lie within this http_request struct.
assert((char*)resp >= (char*)r);
assert((char*)resp < (char*)(r + 1));
size_t len = str.end - str.start;
// Substring must contain no NUL chars.
assert(strnchr(str.start, len, '\0') == NULL);
char *reslim = r->buffer + sizeof r->buffer - 1024; // always leave this much unreserved space
assert(r->reserved <= reslim);
size_t siz = sizeof(char**) + len + 1;
if (r->reserved + siz > reslim) {
r->response.result_code = 414;
return 0;
}
if (r->reserved + siz > r->parsed) {
WARNF("Error during HTTP parsing, unparsed content %s would be overwritten by reserving %s",
alloca_toprint(30, r->parsed, r->end - r->parsed),
alloca_substring_toprint(str)
);
r->response.result_code = 500;
return 0;
}
const char ***respp = (const char ***) r->reserved;
char *restr = (char *)(respp + 1);
if (restr != str.start)
memmove(restr, str.start, len);
restr[len] = '\0';
r->reserved += siz;
assert(r->reserved == &restr[len+1]);
if (r->reserved > r->received)
r->received = r->reserved;
assert(r->received <= r->parsed);
// Only store the pointer _after_ the memmove() above, to avoid overwriting part of the source
// string before we copy it, in the case that the source string is located within r->buffer[].
write_pointer((unsigned char*)respp, resp); // can't use *respp = resp; could cause SIGBUS if not aligned
*resp = restr;
return 1;
}
/* The same as _reserve(), but takes a NUL-terminated string as a source argument instead of a
* substring.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
static int _reserve_str(struct http_request *r, const char **resp, const char *str)
{
struct substring sub = { .start = str, .end = str + strlen(str) };
return _reserve(r, resp, sub);
}
/* Release all the strings reserved by _reserve(), returning the space to the request buffer, and
* resetting to NULL all the pointers to reserved strings that were set by _reserve().
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
static void _release_reserved(struct http_request *r)
{
char *res = r->buffer;
while (res < r->reserved) {
assert(res + sizeof(char**) + 1 <= r->reserved);
const char ***respp = (const char ***) res;
char *restr = (char *)(respp + 1);
const char **resp = read_pointer((const unsigned char*)respp); // can't use resp = *respp; could cause SIGBUS if not aligned
assert((const char*)resp >= (const char*)r);
assert((const char*)resp < (const char*)(r + 1));
assert(*resp == restr);
*resp = NULL;
for (res = restr; res < r->reserved && *res; ++res)
;
assert(res < r->reserved);
assert(*res == '\0');
++res;
}
assert(res == r->reserved);
r->reserved = r->buffer;
}
static inline int _end_of_content(struct http_request *r)
{
return r->cursor == r->end && r->request_content_remaining == 0;
}
static inline int _run_out(struct http_request *r)
{
assert(r->cursor <= r->end);
return r->cursor == r->end;
}
static inline int _buffer_full(struct http_request *r)
{
const char *const bufend = r->buffer + sizeof r->buffer;
return r->parsed == r->received && (r->end == bufend || r->request_content_remaining == 0);
}
static inline void _rewind(struct http_request *r)
{
assert(r->parsed >= r->received);
r->cursor = r->parsed;
}
static inline void _commit(struct http_request *r)
{
assert(r->cursor <= r->end);
r->parsed = r->cursor;
}
static inline int _skip_any(struct http_request *r)
{
if (_run_out(r))
return 0;
++r->cursor;
return 1;
}
static inline void _skip_all(struct http_request *r)
{
r->cursor = r->end;
}
static inline int _skip_crlf(struct http_request *r)
{
return !_run_out(r) && *r->cursor == '\r' && ++r->cursor && !_run_out(r) && *r->cursor == '\n' && ++r->cursor;
}
static inline int _skip_to_crlf(struct http_request *r)
{
for (; !_run_out(r); ++r->cursor)
if (r->cursor + 1 < r->end && r->cursor[0] == '\r' && r->cursor[1] == '\n')
return 1;
return 0;
}
static inline void _rewind_optional_cr(struct http_request *r)
{
if (r->cursor > r->parsed && r->cursor[-1] == '\r')
--r->cursor;
}
static inline void _rewind_crlf(struct http_request *r)
{
assert(r->cursor >= r->parsed + 2);
assert(r->cursor[-2] == '\r');
assert(r->cursor[-1] == '\n');
r->cursor -= 2;
}
/* More permissive than _skip_crlf(), this counts NUL characters preceding and between the CR and LF
* as part of the end-of-line sequence and treats the CR as optional. This allows simple manual
* testing using telnet(1).
*/
static inline int _skip_eol(struct http_request *r)
{
unsigned crcount = 0;
for (; !_run_out(r); ++r->cursor) {
switch (*r->cursor) {
case '\0': // ignore any leading NULs (telnet inserts them)
break;
case '\r': // ignore up to one leading CR
if (++crcount > 1)
return 0;
break;
case '\n':
++r->cursor;
return 1;
default:
return 0;
}
}
return 0;
}
/* More permissive than _skip_crlf(), this counts NUL characters preceding and between the CR and LF
* as part of the end-of-line sequence and treats the CR as optional. This allows simple manual
* testing using telnet(1).
*/
static int _skip_to_eol(struct http_request *r)
{
const char *const start = r->cursor;
while (!_run_out(r) && *r->cursor != '\n')
++r->cursor;
if (_run_out(r))
return 0;
// consume preceding NULs (telnet inserts them)
while (r->cursor > start && r->cursor[-1] == '\0')
--r->cursor;
// consume a single preceding CR
if (r->cursor > start && r->cursor[-1] == '\r')
--r->cursor;
// consume any more preceding NULs
while (r->cursor > start && r->cursor[-1] == '\0')
--r->cursor;
return 1;
}
static int _skip_literal(struct http_request *r, const char *literal)
{
while (!_run_out(r) && *literal && *r->cursor == *literal)
++literal, ++r->cursor;
return *literal == '\0';
}
static int _skip_literal_nocase(struct http_request *r, const char *literal)
{
while (!_run_out(r) && *literal && toupper(*r->cursor) == toupper(*literal))
++literal, ++r->cursor;
return *literal == '\0';
}
static int is_http_space(char c)
{
return c == ' ' || c == '\t';
}
static int _skip_optional_space(struct http_request *r)
{
while (!_run_out(r) && is_http_space(*r->cursor))
++r->cursor;
return 1;
}
static inline int _skip_space(struct http_request *r)
{
const char *const start = r->cursor;
_skip_optional_space(r);
return r->cursor > start;
}
static size_t _skip_word_printable(struct http_request *r, struct substring *str)
{
if (_run_out(r) || isspace(*r->cursor) || !isprint(*r->cursor))
return 0;
const char *start = r->cursor;
for (++r->cursor; !_run_out(r) && !isspace(*r->cursor) && isprint(*r->cursor); ++r->cursor)
;
if (_run_out(r))
return 0;
assert(r->cursor > start);
assert(isspace(*r->cursor));
if (str) {
str->start = start;
str->end = r->cursor;
}
return r->cursor - start;
}
static size_t _skip_token(struct http_request *r, struct substring *str)
{
if (_run_out(r) || !is_http_token(*r->cursor))
return 0;
const char *start = r->cursor;
for (++r->cursor; !_run_out(r) && is_http_token(*r->cursor); ++r->cursor)
;
if (_run_out(r))
return 0;
assert(r->cursor > start);
assert(!is_http_token(*r->cursor));
if (str) {
str->start = start;
str->end = r->cursor;
}
return r->cursor - start;
}
static size_t _parse_token(struct http_request *r, char *dst, size_t dstsiz)
{
struct substring str;
size_t len = _skip_token(r, &str);
if (len && dst) {
size_t cpy = len < dstsiz - 1 ? len : dstsiz - 1;
strncpy(dst, str.start, cpy)[cpy] = '\0';
}
return len;
}
static size_t _parse_quoted_string(struct http_request *r, char *dst, size_t dstsiz)
{
assert(r->cursor <= r->end);
if (_run_out(r) || *r->cursor != '"')
return 0;
int slosh = 0;
size_t len = 0;
for (++r->cursor; !_run_out(r); ++r->cursor) {
if (!isprint(*r->cursor))
return 0;
if (slosh) {
if (dst && len < dstsiz - 1)
dst[len] = *r->cursor;
++len;
slosh = 0;
} else if (*r->cursor == '"')
break;
else if (*r->cursor == '\\')
slosh = 1;
else {
if (dst && len < dstsiz - 1)
dst[len] = *r->cursor;
++len;
}
}
if (dst)
dst[len < dstsiz - 1 ? len : dstsiz - 1] = '\0';
if (_run_out(r))
return 0;
assert(*r->cursor == '"');
++r->cursor;
return len;
}
static size_t _parse_token_or_quoted_string(struct http_request *r, char *dst, size_t dstsiz)
{
assert(dstsiz > 0);
if (!_run_out(r) && *r->cursor == '"')
return _parse_quoted_string(r, dst, dstsiz);
return _parse_token(r, dst, dstsiz);
}
static inline int _parse_http_size_t(struct http_request *r, http_size_t *szp)
{
return !_run_out(r) && isdigit(*r->cursor) && str_to_uint64(r->cursor, 10, szp, (const char **)&r->cursor);
}
static inline int _parse_uint32(struct http_request *r, uint32_t *uint32p)
{
return !_run_out(r) && isdigit(*r->cursor) && str_to_uint32(r->cursor, 10, uint32p, (const char **)&r->cursor);
}
static unsigned _parse_ranges(struct http_request *r, struct http_range *range, unsigned nrange)
{
unsigned i = 0;
while (1) {
enum http_range_type type;
http_size_t first = 0, last = 0;
if (_skip_literal(r, "-")) {
if (!_parse_http_size_t(r, &last))
return 0;
type = SUFFIX;
}
else if (_parse_http_size_t(r, &first) && _skip_literal(r, "-")) {
if (_parse_http_size_t(r, &last)) {
if (last < first)
return 0;
type = CLOSED;
} else
type = OPEN;
} else
return 0;
if (i < nrange) {
range[i].type = type;
range[i].first = first;
range[i].last = last;
}
++i;
if (!_skip_literal(r, ","))
break;
_skip_optional_space(r);
}
return i;
}
static int _parse_content_type(struct http_request *r, struct mime_content_type *ct)
{
size_t n = _parse_token(r, ct->type, sizeof ct->type);
if (n == 0)
return 0;
if (n >= sizeof ct->type) {
WARNF("HTTP Content-Type type truncated: %s", alloca_str_toprint(ct->type));
return 0;
}
if (!_skip_literal(r, "/"))
return 0;
n = _parse_token(r, ct->subtype, sizeof ct->subtype);
if (n == 0)
return 0;
if (n >= sizeof ct->subtype) {
WARNF("HTTP Content-Type subtype truncated: %s", alloca_str_toprint(ct->subtype));
return 0;
}
while (_skip_optional_space(r) && _skip_literal(r, ";") && _skip_optional_space(r)) {
char *start = r->cursor;
if (_skip_literal(r, "charset=")) {
size_t n = _parse_token_or_quoted_string(r, ct->charset, sizeof ct->charset);
if (n == 0)
return 0;
if (n >= sizeof ct->charset) {
WARNF("HTTP Content-Type charset truncated: %s", alloca_str_toprint(ct->charset));
return 0;
}
continue;
}
r->cursor = start;
if (_skip_literal(r, "boundary=")) {
size_t n = _parse_token_or_quoted_string(r, ct->multipart_boundary, sizeof ct->multipart_boundary);
if (n == 0)
return 0;
if (n >= sizeof ct->multipart_boundary) {
WARNF("HTTP Content-Type boundary truncated: %s", alloca_str_toprint(ct->multipart_boundary));
return 0;
}
continue;
}
r->cursor = start;
if (_skip_literal(r, "format=")) {
size_t n = _parse_token_or_quoted_string(r, ct->format, sizeof ct->format);
if (n == 0)
return 0;
if (n >= sizeof ct->format) {
WARNF("HTTP Content-Type format truncated: %s", alloca_str_toprint(ct->format));
return 0;
}
continue;
}
r->cursor = start;
struct substring param;
if (_skip_token(r, &param) && _skip_literal(r, "=") && _parse_token_or_quoted_string(r, NULL, 0)) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Skipping HTTP Content-Type parameter: %s", alloca_substring_toprint(param));
continue;
}
WARNF("Malformed HTTP Content-Type: %s", alloca_toprint(50, r->cursor, r->end - r->cursor));
return 0;
}
return 1;
}
static size_t _parse_base64(struct http_request *r, char *bin, size_t binsize)
{
return base64_decode((unsigned char *)bin, binsize, r->cursor, r->end - r->cursor, (const char **)&r->cursor, B64_CONSUME_ALL, is_http_space);
}
static int _parse_authorization_credentials_basic(struct http_request *r, struct http_client_credentials_basic *cred, char *buf, size_t bufsz)
{
size_t n = _parse_base64(r, buf, bufsz - 1); // leave room for NUL terminator on password
assert(n < bufsz); // buffer must be big enough
char *pw = (char *) strnchr(buf, n, ':');
if (pw == NULL)
return 0; // malformed
cred->user = buf;
*pw++ = '\0'; // NUL terminate user
cred->password = pw;
buf[n] = '\0'; // NUL terminate password
return 1;
}
static int _parse_authorization(struct http_request *r, struct http_client_authorization *auth, size_t header_bytes)
{
char *start = r->cursor;
if (_skip_literal(r, "Basic") && _skip_space(r)) {
size_t bufsz = 5 + header_bytes * 3 / 4; // enough for base64 decoding
char buf[bufsz];
if (_parse_authorization_credentials_basic(r, &auth->credentials.basic, buf, bufsz)) {
auth->scheme = BASIC;
_commit(r); // make room for following reservations
if ( !_reserve_str(r, &auth->credentials.basic.user, auth->credentials.basic.user)
|| !_reserve_str(r, &auth->credentials.basic.password, auth->credentials.basic.password)
)
return 0; // error
return 1;
}
if (r->debug_flag && *r->debug_flag)
DEBUGF("Malformed HTTP header: Authorization: %s", alloca_toprint(50, start, header_bytes));
return 0;
}
if (_skip_literal(r, "Digest") && _skip_space(r)) {
if (r->debug_flag && *r->debug_flag)
DEBUG("Ignoring unsupported HTTP Authorization scheme: Digest");
r->cursor += header_bytes;
return 1;
}
struct substring scheme;
if (_skip_token(r, &scheme) && _skip_space(r)) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Unrecognised HTTP Authorization scheme: %s", alloca_toprint(-1, scheme.start, scheme.end - scheme.start));
return 0;
}
if (r->debug_flag && *r->debug_flag)
DEBUGF("Malformed HTTP Authorization header: %s", alloca_toprint(50, r->parsed, r->end - r->parsed));
return 0;
}
static int _parse_quoted_rfc822_time(struct http_request *r, time_t *timep)
{
char datestr[40];
size_t n = _parse_quoted_string(r, datestr, sizeof datestr);
if (n == 0 || n >= sizeof datestr)
return 0;
// TODO: Move the following code into its own function in str.c
struct tm tm;
bzero(&tm, sizeof tm);
// TODO: Ensure this works in non-English locales, ie, "%a" still accepts "Mon", "Tue" etc. and
// "%b" still accepts "Jan", "Feb" etc.
// TODO: Support symbolic time zones, eg, "UT", "GMT", "UTC", "EST"...
const char *c = strptime(datestr, "%a, %d %b %Y %T ", &tm);
if ((c[0] == '-' || c[0] == '+') && isdigit(c[1]) && isdigit(c[2]) && isdigit(c[3]) && isdigit(c[4]) && c[5] == '\0') {
time_t zone = (c[0] == '-' ? -1 : 1) * ((c[1] - '0') * 600 + (c[2] - '0') * 60 + (c[3] - '0') * 10 + (c[4] - '0'));
const char *tz = getenv("TZ");
if (tz)
tz = alloca_strdup(tz);
setenv("TZ", "", 1);
tzset();
*timep = mktime(&tm) - zone;
if (tz)
setenv("TZ", tz, 1);
else
unsetenv("TZ");
tzset();
return 1;
}
return 0;
}
/* If parsing completes, then sets r->parser to the next parsing function and returns 0. If parsing
* cannot complete due to running out of data, returns 100 without changing r->parser, so this
* function will be called again once more data has been read. Returns a 4nn or 5nn HTTP result
* code if parsing fails. Returns -1 if an unexpected error occurs.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
static int http_request_parse_verb(struct http_request *r)
{
DEBUG_DUMP_PARSER(r);
_rewind(r);
assert(r->cursor >= r->received);
assert(!_run_out(r));
// Parse verb: GET, PUT, POST, etc.
assert(r->verb == NULL);
unsigned i;
for (i = 0; i < NELS(http_verbs); ++i) {
_rewind(r);
if (_skip_literal(r, http_verbs[i].word) && _skip_literal(r, " ")) {
r->verb = http_verbs[i].word;
break;
}
if (_run_out(r))
return 100; // read more and try again
}
if (r->verb == NULL) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Malformed HTTP request, invalid verb: %s", alloca_toprint(20, r->cursor, r->end - r->cursor));
return 400;
}
_commit(r);
r->parser = http_request_parse_path;
return 0;
}
/* If parsing completes, then sets r->parser to the next parsing function and returns 0. If parsing
* cannot complete due to running out of data, returns 100 without changing r->parser, so this
* function will be called again once more data has been read. Returns a 4nn or 5nn HTTP result
* code if parsing fails. Returns -1 if an unexpected error occurs.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
static int http_request_parse_path(struct http_request *r)
{
DEBUG_DUMP_PARSER(r);
// Parse path: word immediately following verb, delimited by spaces.
assert(r->path == NULL);
struct substring path;
if (!(_skip_word_printable(r, &path) && _skip_literal(r, " "))) {
if (_run_out(r))
return 100; // read more and try again
if (r->debug_flag && *r->debug_flag)
DEBUGF("Malformed HTTP %s request at path: %s", r->verb, alloca_toprint(20, r->parsed, r->end - r->parsed));
return 400;
}
_commit(r);
if (!_reserve(r, &r->path, path))
return 0; // error
r->parser = http_request_parse_http_version;
return 0;
}
/* If parsing completes, then sets r->parser to the next parsing function and returns 0. If parsing
* cannot complete due to running out of data, returns 100 without changing r->parser, so this
* function will be called again once more data has been read. Returns a 4nn or 5nn HTTP result
* code if parsing fails. Returns -1 if an unexpected error occurs.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
static int http_request_parse_http_version(struct http_request *r)
{
DEBUG_DUMP_PARSER(r);
// Parse HTTP version: HTTP/m.n followed by CRLF.
assert(r->version_major == 0);
assert(r->version_minor == 0);
uint32_t major, minor;
if (!( _skip_literal(r, "HTTP/")
&& _parse_uint32(r, &major)
&& major > 0 && major < UINT8_MAX
&& _skip_literal(r, ".")
&& _parse_uint32(r, &minor)
&& minor < UINT8_MAX
&& _skip_eol(r)
)
) {
if (_run_out(r))
return 100; // read more and try again
if (r->debug_flag && *r->debug_flag)
DEBUGF("Malformed HTTP %s request at version: %s", r->verb, alloca_toprint(20, r->parsed, r->end - r->parsed));
return 400;
}
_commit(r);
r->version_major = major;
r->version_minor = minor;
r->parser = http_request_start_parsing_headers;
if (r->handle_first_line)
return r->handle_first_line(r);
return 0; // parsing complete
}
/* Select the header parser. Returns 0 after setting the new parser function. Returns a 4nn or 5nn
* HTTP result code if the request cannot be handled (eg, unsupported HTTP version or invalid path).
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
static int http_request_start_parsing_headers(struct http_request *r)
{
DEBUG_DUMP_PARSER(r);
assert(r->verb != NULL);
assert(r->path != NULL);
assert(r->version_major != 0);
if (r->version_major != 1) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Unsupported HTTP version: %u.%u", r->version_major, r->version_minor);
return 400;
}
r->parser = http_request_parse_header;
return 0;
}
/* Parse one request header line.
*
* If the end of headers is parsed (blank line), then sets r->parser to the next parsing function
* and returns 0. If a single header line is successfully parsed, returns 0 after advancing
* r->parsed. If parsing cannot complete due to running out of data, returns 0 without changing
* r->parser, so this function will be called again once more data has been read. Returns a 4nn or
* 5nn HTTP result code if parsing fails. Returns -1 if an unexpected error occurs.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
static int http_request_parse_header(struct http_request *r)
{
DEBUG_DUMP_PARSER(r);
_skip_to_eol(r);
const char *const eol = r->cursor;
_skip_eol(r);
if (eol == r->parsed) { // if EOL is at start of line (ie, blank line)...
_commit(r);
if (r->request_header.content_length != CONTENT_LENGTH_UNKNOWN) {
size_t unparsed = r->end - r->parsed;
if (unparsed > r->request_header.content_length) {
WARNF("HTTP parsing: already read %zu bytes past end of content", (size_t)(unparsed - r->request_header.content_length));
r->request_content_remaining = 0;
}
else
r->request_content_remaining = r->request_header.content_length - unparsed;
}
r->parser = http_request_start_body;
if (r->handle_headers)
return r->handle_headers(r);
return 0;
}
char *const nextline = r->cursor;
_rewind(r);
const char *const sol = r->cursor;
if (_skip_literal_nocase(r, "Content-Length:")) {
if (r->request_header.content_length != CONTENT_LENGTH_UNKNOWN) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Skipping duplicate HTTP header Content-Length: %s", alloca_toprint(50, sol, r->end - sol));
r->cursor = nextline;
_commit(r);
return 0;
}
_skip_optional_space(r);
http_size_t length;
if (_parse_http_size_t(r, &length) && _skip_optional_space(r) && r->cursor == eol) {
r->cursor = nextline;
_commit(r);
r->request_header.content_length = length;
if (r->debug_flag && *r->debug_flag)
DEBUGF("Parsed HTTP request Content-Length: %"PRIhttp_size_t, r->request_header.content_length);
return 0;
}
goto malformed;
}
_rewind(r);
if (_skip_literal_nocase(r, "Content-Type:")) {
if (r->request_header.content_type.type[0]) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Skipping duplicate HTTP header Content-Type: %s", alloca_toprint(50, sol, r->end - sol));
r->cursor = nextline;
_commit(r);
return 0;
}
_skip_optional_space(r);
if ( _parse_content_type(r, &r->request_header.content_type)
&& _skip_optional_space(r)
&& r->cursor == eol
) {
r->cursor = nextline;
_commit(r);
if (r->debug_flag && *r->debug_flag)
DEBUGF("Parsed HTTP request Content-type: %s", alloca_mime_content_type(&r->request_header.content_type));
return 0;
}
goto malformed;
}
_rewind(r);
if (_skip_literal_nocase(r, "Range:")) {
if (r->request_header.content_range_count) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Skipping duplicate HTTP header Range: %s", alloca_toprint(50, sol, r->end - sol));
r->cursor = nextline;
_commit(r);
return 0;
}
_skip_optional_space(r);
unsigned int n;
if ( _skip_literal(r, "bytes=")
&& (n = _parse_ranges(r, r->request_header.content_ranges, NELS(r->request_header.content_ranges)))
&& _skip_optional_space(r)
&& r->cursor == eol
) {
r->cursor = nextline;
_commit(r);
if (n > NELS(r->request_header.content_ranges)) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("HTTP request Range header overflow (%u ranges in set, can only handle %zu): %s",
n, NELS(r->request_header.content_ranges), alloca_toprint(-1, sol, eol - sol));
// In this case ignore the Range: header -- respond with the entire resource.
r->request_header.content_range_count = 0;
} else {
r->request_header.content_range_count = n;
if (r->debug_flag && *r->debug_flag)
DEBUGF("Parsed HTTP request Range: bytes=%s", alloca_http_ranges(r->request_header.content_ranges));
}
return 0;
}
goto malformed;
}
_rewind(r);
if (_skip_literal_nocase(r, "Authorization:")) {
if (r->request_header.authorization.scheme != NOAUTH) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Skipping duplicate HTTP header Authorization: %s", alloca_toprint(50, sol, r->end - sol));
r->cursor = nextline;
_commit(r);
return 0;
}
_skip_optional_space(r);
if ( _parse_authorization(r, &r->request_header.authorization, eol - r->cursor)
&& _skip_optional_space(r)
&& r->cursor == eol
) {
assert(r->request_header.authorization.scheme != NOAUTH);
r->cursor = nextline;
_commit(r);
return 0;
}
if (r->response.result_code)
return r->response.result_code;
goto malformed;
}
_rewind(r);
if (_skip_literal_nocase(r, "Origin:")) {
if (r->request_header.origin) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Skipping duplicate HTTP header Origin: %s", alloca_toprint(50, sol, r->end - sol));
r->cursor = nextline;
_commit(r);
return 0;
}
_skip_optional_space(r);
struct substring origin;
if (_skip_word_printable(r, &origin)
&& _skip_optional_space(r)
&& r->cursor == eol) {
r->cursor = nextline;
_commit(r);
_reserve(r, &r->request_header.origin, origin);
return 0;
}
goto malformed;
}
_rewind(r);
if (r->debug_flag && *r->debug_flag)
DEBUGF("Skipped HTTP request header: %s", alloca_toprint(-1, sol, eol - sol));
r->cursor = nextline;
_commit(r);
return 0;
malformed:
if (r->debug_flag && *r->debug_flag)
DEBUGF("Malformed HTTP request header: %s", alloca_toprint(-1, sol, eol - sol));
return 400;
}
/* If parsing completes, then sets r->parser to the next parsing function and returns 0. If parsing
* cannot complete due to running out of data, returns 0 without changing r->parser, so this
* function will be called again once more data has been read. Returns a 4nn or 5nn HTTP result
* code if parsing fails. Returns -1 if an unexpected error occurs.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
static int http_request_start_body(struct http_request *r)
{
DEBUG_DUMP_PARSER(r);
assert(r->verb != NULL);
assert(r->path != NULL);
assert(r->version_major != 0);
assert(r->parsed <= r->end);
if (r->verb == HTTP_VERB_GET) {
// TODO: Implement HEAD requests (only send response header, not body)
if (r->request_header.content_length != 0 && r->request_header.content_length != CONTENT_LENGTH_UNKNOWN) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Malformed HTTP %s request: non-zero Content-Length not allowed", r->verb);
return 400;
}
if (r->request_header.content_type.type[0]) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Malformed HTTP %s request: Content-Type not allowed", r->verb);
return 400;
}
r->parser = NULL;
}
else if (r->verb == HTTP_VERB_POST) {
if (r->request_header.content_length == CONTENT_LENGTH_UNKNOWN) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Malformed HTTP %s request: missing Content-Length header", r->verb);
return 411;
}
if (r->request_header.content_length == 0) {
r->parser = http_request_reject_content;
} else {
if (r->request_header.content_type.type[0] == '\0') {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Malformed HTTP %s request: missing Content-Type header", r->verb);
return 400;
}
if ( strcmp(r->request_header.content_type.type, "multipart") == 0
&& strcmp(r->request_header.content_type.subtype, "form-data") == 0
) {
if ( r->request_header.content_type.multipart_boundary == NULL
|| r->request_header.content_type.multipart_boundary[0] == '\0'
) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Malformed HTTP %s request: Content-Type %s/%s missing boundary parameter",
r->verb, r->request_header.content_type.type, r->request_header.content_type.subtype);
return 400;
}
r->parser = http_request_parse_body_form_data;
r->form_data_state = START;
} else {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Unsupported HTTP %s request: Content-Type %s not supported",
r->verb, alloca_mime_content_type(&r->request_header.content_type));
return 415;
}
}
}
else {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Unsupported HTTP %s request", r->verb);
r->parser = NULL;
return 501;
}
if (_run_out(r))
return 100;
return 0;
}
/* A special content parser that rejects any content, used when a Content-Type: 0 header was
* received.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
static int http_request_reject_content(struct http_request *r)
{
if (r->debug_flag && *r->debug_flag) {
if (r->request_header.content_length != CONTENT_LENGTH_UNKNOWN)
DEBUGF("Malformed HTTP %s request (Content-Length %"PRIhttp_size_t"): spurious content", r->verb, r->request_header.content_length);
else
DEBUGF("Malformed HTTP %s request: spurious content", r->verb);
}
return 400;
}
/* Returns 1 if a MIME delimiter is skipped, 2 if a MIME close-delimiter is skipped.
*/
static int _skip_mime_boundary(struct http_request *r)
{
if (!_skip_literal(r, "--") || !_skip_literal(r, r->request_header.content_type.multipart_boundary))
return 0;
if (_skip_literal(r, "--") && _skip_crlf(r))
return 2;
if (_skip_crlf(r))
return 1;
return 0;
}
static int _parse_content_disposition(struct http_request *r, struct mime_content_disposition *cd)
{
size_t n = _parse_token(r, cd->type, sizeof cd->type);
if (n == 0)
return 0;
if (n >= sizeof cd->type) {
WARNF("HTTP Content-Disposition type truncated: %s", alloca_str_toprint(cd->type));
return 0;
}
while (_skip_optional_space(r) && _skip_literal(r, ";") && _skip_optional_space(r)) {
char *start = r->cursor;
if (_skip_literal(r, "filename=")) {
size_t n = _parse_token_or_quoted_string(r, cd->filename, sizeof cd->filename);
if (n == 0)
return 0;
if (n >= sizeof cd->filename) {
WARNF("HTTP Content-Disposition filename truncated: %s", alloca_str_toprint(cd->filename));
return 0;
}
continue;
}
r->cursor = start;
if (_skip_literal(r, "name=")) {
size_t n = _parse_token_or_quoted_string(r, cd->name, sizeof cd->name);
if (n == 0)
return 0;
if (n >= sizeof cd->name) {
WARNF("HTTP Content-Disposition name truncated: %s", alloca_str_toprint(cd->name));
return 0;
}
continue;
}
r->cursor = start;
if (_skip_literal(r, "size=")) {
if (!_parse_http_size_t(r, &cd->size))
goto malformed;
continue;
}
r->cursor = start;
if (_skip_literal(r, "creation-date=")) {
if (!_parse_quoted_rfc822_time(r, &cd->creation_date))
goto malformed;
continue;
}
r->cursor = start;
if (_skip_literal(r, "modification-date=")) {
if (!_parse_quoted_rfc822_time(r, &cd->modification_date))
goto malformed;
continue;
}
r->cursor = start;
if (_skip_literal(r, "read-date=")) {
if (!_parse_quoted_rfc822_time(r, &cd->read_date))
goto malformed;
continue;
}
r->cursor = start;
struct substring param;
if (_skip_token(r, &param) && _skip_literal(r, "=") && _parse_token_or_quoted_string(r, NULL, 0)) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Skipping HTTP Content-Disposition parameter: %s", alloca_substring_toprint(param));
continue;
}
malformed:
WARNF("Malformed HTTP Content-Disposition: %s", alloca_toprint(50, r->cursor, r->end - r->cursor));
return 0;
}
return 1;
}
#define _HANDLER_RESULT(result) do { \
if (r->phase != RECEIVE) \
return 1; \
if (result) { \
assert((result) >= 400); \
assert((result) < 600); \
return (result); \
} \
} while (0)
#define _INVOKE_HANDLER_VOID(FUNC) do { \
if (r->form_data.FUNC) { \
if (r->debug_flag && *r->debug_flag) \
DEBUGF(#FUNC "()"); \
int result = r->form_data.FUNC(r); \
_HANDLER_RESULT(result); \
} \
} while (0)
#define _INVOKE_HANDLER_BUF_LEN(FUNC, START, END) do { \
if (r->form_data.FUNC && (START) != (END)) { \
if (r->debug_flag && *r->debug_flag) \
DEBUGF(#FUNC "(%s length=%zu)", alloca_toprint(50, (START), (END) - (START)), (END) - (START)); \
int result = r->form_data.FUNC(r, (START), (END) - (START)); \
_HANDLER_RESULT(result); \
} \
} while (0)
static int http_request_form_data_start_part(struct http_request *r, int b)
{
switch (r->form_data_state) {
case BODY:
if ( r->part_header.content_length != CONTENT_LENGTH_UNKNOWN
&& r->part_body_length != r->part_header.content_length
) {
WARNF("HTTP multipart part body length (%"PRIhttp_size_t") does not match Content-Length header (%"PRIhttp_size_t")",
r->part_body_length,
r->part_header.content_length
);
}
// fall through...
case HEADER:
_INVOKE_HANDLER_VOID(handle_mime_part_end);
break;
default:
break;
}
if (b == 1) {
r->form_data_state = HEADER;
bzero(&r->part_header, sizeof r->part_header);
r->part_body_length = 0;
r->part_header.content_length = CONTENT_LENGTH_UNKNOWN;
_INVOKE_HANDLER_VOID(handle_mime_part_start);
} else
r->form_data_state = EPILOGUE;
return 0;
}
/* If parsing completes (ie, parsed to end of epilogue), then sets r->parser to NULL and returns 0,
* so this function will not be called again. If parsing cannot complete due to running out of
* data, returns 100, so this function will not be called again until more data has been read.
* Returns a 4nn or 5nn HTTP result code if parsing fails. Returns -1 if an unexpected error
* occurs.
*
* NOTE: No support for nested/mixed parts, as that would considerably complicate the parser. If
* the need arises in future, we will deal with it then. In the meantime, we will have something
* that meets our immediate needs for Rhizome Direct and the RESTful API.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
static int http_request_parse_body_form_data(struct http_request *r)
{
DEBUG_DUMP_PARSER(r);
int at_start = 0;
switch (r->form_data_state) {
case START:
if (config.debug.http_server)
DEBUGF("START");
// The logic here allows for a missing initial CRLF before the first boundary line.
at_start = 1;
r->form_data_state = PREAMBLE;
// fall through
case PREAMBLE: {
if (config.debug.http_server)
DEBUGF("PREAMBLE");
char *start = r->parsed;
while (at_start || _skip_to_crlf(r)) {
char *end_preamble = r->cursor;
int b;
if ((at_start || _skip_crlf(r)) && (b = _skip_mime_boundary(r))) {
assert(end_preamble >= r->parsed);
_INVOKE_HANDLER_BUF_LEN(handle_mime_preamble, start, end_preamble);
_rewind_crlf(r);
_commit(r);
return http_request_form_data_start_part(r, b);
}
if (!at_start) {
r->cursor = end_preamble;
_skip_any(r);
}
at_start = 0;
}
if (_end_of_content(r)) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Malformed HTTP %s form data: missing first boundary", r->verb);
return 400;
}
_rewind_optional_cr(r);
_commit(r);
assert(r->parsed >= start);
_INVOKE_HANDLER_BUF_LEN(handle_mime_preamble, start, r->parsed);
}
return 100; // need more data
case HEADER: {
if (config.debug.http_server)
DEBUGF("HEADER");
// If not at a CRLF, then we are skipping through an over-long header that didn't
// fit into the buffer. Just discard bytes up to the next CRLF.
if (!_skip_crlf(r)) {
_skip_to_crlf(r); // advance to next CRLF or end of buffer
_rewind_optional_cr(r); // don't skip a CR at end of buffer (it might be part of a half-received CRLF)
assert(r->cursor > r->parsed);
if (r->debug_flag && *r->debug_flag)
DEBUGF("skipping %zu header bytes", r->cursor - r->parsed);
_commit(r);
return 0;
}
char *const sol = r->cursor;
// A blank line finishes the headers. The CRLF does not form part of the body.
if (_skip_crlf(r)) {
_commit(r);
if (r->form_data.handle_mime_part_header) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("handle_mime_part_header(Content-Length: %"PRIhttp_size_t", Content-Type: %s, Content-Disposition: %s)",
r->part_header.content_length,
alloca_mime_content_type(&r->part_header.content_type),
alloca_mime_content_disposition(&r->part_header.content_disposition)
);
int result = r->form_data.handle_mime_part_header(r, &r->part_header);
_HANDLER_RESULT(result); \
}
r->form_data_state = BODY;
return 0;
}
if (_run_out(r))
return 100; // read more and try again
r->cursor = sol;
// A mime boundary technically should not occur in the middle of the headers, but if it
// does, treat it as a zero-length body.
int b;
if ((b = _skip_mime_boundary(r))) {
_rewind_crlf(r);
_commit(r);
// A boundary in the middle of headers finishes the current part and starts a new part.
// An end boundary terminates the current part and starts the epilogue.
return http_request_form_data_start_part(r, b);
}
if (_run_out(r))
return 100; // read more and try again
r->cursor = sol;
struct substring label;
if (_skip_token(r, &label) && _skip_literal(r, ":") && _skip_optional_space(r)) {
size_t labellen = label.end - label.start;
char labelstr[labellen + 1];
strncpy(labelstr, label.start, labellen)[labellen] = '\0';
str_tolower_inplace(labelstr);
if (strcmp(labelstr, "content-length") == 0) {
if (r->part_header.content_length != CONTENT_LENGTH_UNKNOWN) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Skipping duplicate HTTP multipart header %s", alloca_toprint(50, sol, r->end - sol));
return 400;
}
http_size_t length;
if (_parse_http_size_t(r, &length) && _skip_optional_space(r) && _skip_crlf(r)) {
_rewind_crlf(r);
_commit(r);
r->part_header.content_length = length;
if (r->debug_flag && *r->debug_flag)
DEBUGF("Parsed HTTP multipart header Content-Length: %"PRIhttp_size_t, r->part_header.content_length);
return 0;
}
}
else if (strcmp(labelstr, "content-type") == 0) {
if (r->part_header.content_type.type[0]) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Skipping duplicate HTTP multipart header %s", alloca_toprint(50, sol, r->end - sol));
return 400;
}
if (_parse_content_type(r, &r->part_header.content_type) && _skip_optional_space(r) && _skip_crlf(r)) {
_rewind_crlf(r);
_commit(r);
if (r->debug_flag && *r->debug_flag)
DEBUGF("Parsed HTTP multipart header Content-Type: %s", alloca_mime_content_type(&r->part_header.content_type));
return 0;
}
}
else if (strcmp(labelstr, "content-disposition") == 0) {
if (r->part_header.content_disposition.type[0]) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Skipping duplicate HTTP multipart header %s", alloca_toprint(50, sol, r->end - sol));
return 400;
}
if (_parse_content_disposition(r, &r->part_header.content_disposition) && _skip_optional_space(r) && _skip_crlf(r)) {
_rewind_crlf(r);
_commit(r);
if (r->debug_flag && *r->debug_flag)
DEBUGF("Parsed HTTP multipart header Content-Disposition: %s", alloca_mime_content_disposition(&r->part_header.content_disposition));
return 0;
}
}
else if (_skip_to_crlf(r)) {
_commit(r);
if (r->debug_flag && *r->debug_flag)
DEBUGF("Skip HTTP multipart header: %s", alloca_toprint(50, sol, r->parsed - sol));
return 0;
}
}
r->cursor = sol;
if (_buffer_full(r)) {
// The line does not start with "Token:" and is too long to fit into the buffer. Start
// skipping it.
WARNF("Skipping unterminated HTTP MIME header %s", alloca_toprint(50, sol, r->end - sol));
r->cursor = r->end;
_rewind_optional_cr(r);
if (r->debug_flag && *r->debug_flag)
DEBUGF("skipping %zu header bytes", r->cursor - r->parsed);
_commit(r);
return 0;
}
if (_run_out(r))
return 100; // read more and try again
if (r->debug_flag && *r->debug_flag)
DEBUGF("Malformed HTTP %s form data part: invalid header %s", r->verb, alloca_toprint(50, sol, r->end - sol));
DEBUG_DUMP_PARSER(r);
}
return 400;
case BODY:
if (config.debug.http_server)
DEBUGF("BODY");
char *start = r->parsed;
while (_skip_to_crlf(r)) {
int b;
char *end_body = r->cursor;
_skip_crlf(r);
if ((b = _skip_mime_boundary(r))) {
_rewind_crlf(r);
_commit(r);
assert(end_body >= start);
r->part_body_length += end_body - start;
// Note: the handler function may modify the data in-place (eg, Rhizome does encryption
// that way).
_INVOKE_HANDLER_BUF_LEN(handle_mime_body, start, end_body); // excluding CRLF at end
return http_request_form_data_start_part(r, b);
}
}
if (_end_of_content(r)) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Malformed HTTP %s form data part: missing end boundary", r->verb);
return 400;
}
_rewind_optional_cr(r);
_commit(r);
assert(r->parsed >= start);
r->part_body_length += r->parsed - start;
// Note: the handler function may modify the data in-place
_INVOKE_HANDLER_BUF_LEN(handle_mime_body, start, r->parsed);
return 100; // need more data
case EPILOGUE:
if (config.debug.http_server)
DEBUGF("EPILOGUE");
r->cursor = r->end;
assert(r->cursor >= r->parsed);
_INVOKE_HANDLER_BUF_LEN(handle_mime_epilogue, r->parsed, r->cursor);
_commit(r);
assert(_run_out(r));
if (_end_of_content(r))
return 0; // done
return 100; // need more data
default:
FATALF("form_data_state = %d", r->form_data_state);
}
abort(); // not reached
}
static ssize_t http_request_read(struct http_request *r, char *buf, size_t len)
{
sigPipeFlag = 0;
ssize_t bytes = read_nonblock(r->alarm.poll.fd, buf, len);
if (bytes == -1) {
if (r->debug_flag && *r->debug_flag)
DEBUG("HTTP socket read error, closing connection");
http_request_finalise(r);
return -1;
}
if (sigPipeFlag) {
if (r->debug_flag && *r->debug_flag)
DEBUG("Received SIGPIPE on HTTP socket read, closing connection");
http_request_finalise(r);
return -1;
}
return bytes;
}
static void http_request_receive(struct http_request *r)
{
assert(r->phase == RECEIVE);
const char *const bufend = r->buffer + sizeof r->buffer;
assert(r->end <= bufend);
assert(r->parsed >= r->received);
assert(r->parsed <= r->end);
// If the end of content falls within the buffer, then there is no need to make any more room,
// just read up to the end of content. Otherwise, If buffer is running short on unused space,
// shift existing content in buffer down to make more room if possible.
size_t room = bufend - r->end;
if (r->request_content_remaining != CONTENT_LENGTH_UNKNOWN && room > r->request_content_remaining)
room = r->request_content_remaining;
else {
size_t spare = r->parsed - r->received;
if (spare && (room < 128 || (room < 1024 && spare >= 32))) {
size_t unparsed = r->end - r->parsed;
memmove((char *)r->received, r->parsed, unparsed); // memcpy() does not handle overlapping src and dst
r->parsed = r->received;
r->end = r->received + unparsed;
room = bufend - r->end;
if (r->request_content_remaining != CONTENT_LENGTH_UNKNOWN && room > r->request_content_remaining)
room = r->request_content_remaining;
}
}
// If there is no more buffer space, fail the request.
if (room == 0) {
if (r->debug_flag && *r->debug_flag)
DEBUG("Buffer size reached, reporting overflow");
http_request_simple_response(r, 431, NULL);
return;
}
// Read up to the end of available buffer space or the end of content, whichever is first. Read
// as many bytes as possible into the unused buffer space. Any read error closes the connection
// without any response.
assert(room > 0);
if (r->request_content_remaining != CONTENT_LENGTH_UNKNOWN)
assert(room <= r->request_content_remaining);
ssize_t bytes = http_request_read(r, (char *)r->end, room);
if (bytes == -1)
return;
assert((size_t) bytes <= room);
// If no data was read, then just return to polling. Don't drop the connection on an empty read,
// because that drops connections when they shouldn't, including during testing. The inactivity
// timeout will drop inactive connections.
if (bytes == 0)
return;
r->end += (size_t) bytes;
if (r->request_content_remaining != CONTENT_LENGTH_UNKNOWN)
r->request_content_remaining -= (size_t) bytes;
// We got some data, so reset the inactivity timer and invoke the parsing state machine to process
// it. The state machine invokes the caller-supplied callback functions.
http_request_set_idle_timeout(r);
// Parse the unparsed and received data.
while (r->phase == RECEIVE) {
int result;
_rewind(r);
DEBUG_DUMP_PARSER(r);
if (_end_of_content(r)) {
if (r->handle_content_end)
result = r->handle_content_end(r);
else {
if (r->debug_flag && *r->debug_flag)
DEBUG("Internal failure parsing HTTP request: no end-of-content function set");
result = 500;
}
} else {
HTTP_REQUEST_PARSER *oldparser = r->parser;
const char *oldparsed = r->parsed;
if (r->parser == NULL) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("No HTTP parser function set -- skipping %zu bytes", (size_t)(r->end - r->cursor));
_skip_all(r);
_commit(r);
result = 0;
} else {
result = r->parser(r);
assert(r->parsed >= oldparsed);
}
if (r->phase != RECEIVE)
break;
if (result == 100)
return; // needs more data; poll again
if (result == 0 && r->parsed == oldparsed && r->parser == oldparser) {
if (r->debug_flag && *r->debug_flag)
DEBUG("Internal failure parsing HTTP request: parser function did not advance");
DEBUG_DUMP_PARSER(r);
result = 500;
}
}
if (result >= 200 && result < 600) {
assert(r->response.result_code == 0 || r->response.result_code == result);
r->response.result_code = result;
} else if (result) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Internal failure parsing HTTP request: invalid result=%d", result);
r->response.result_code = 500;
}
if (r->response.result_code)
break;
if (result == -1) {
if (r->debug_flag && *r->debug_flag)
DEBUG("Unrecoverable error parsing HTTP request, closing connection");
http_request_finalise(r);
return;
}
}
if (r->phase != RECEIVE) {
assert(r->response.result_code != 0);
return;
}
if (r->response.result_code == 0) {
WHY("No HTTP response set, using 500 Server Error");
r->response.result_code = 500;
}
http_request_start_response(r);
}
/* Write the current contents of the response buffer to the HTTP socket. When no more bytes can be
* written, return so that socket polling can continue. Once all bytes are sent, if there is a
* content generator function, invoke it to put more content in the response buffer, and write that
* content.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
static void http_request_send_response(struct http_request *r)
{
assert(r->phase == TRANSMIT);
while (1) {
if (r->response_length != CONTENT_LENGTH_UNKNOWN)
assert(r->response_sent <= r->response_length);
assert(r->response_buffer_sent <= r->response_buffer_length);
uint64_t remaining = CONTENT_LENGTH_UNKNOWN;
size_t unsent = r->response_buffer_length - r->response_buffer_sent;
if (r->debug_flag && *r->debug_flag)
DEBUGF("HTTP response buffer contains %zu bytes unsent", unsent);
if (r->response_length != CONTENT_LENGTH_UNKNOWN) {
remaining = r->response_length - r->response_sent;
assert(unsent <= remaining);
assert(r->response_buffer_need <= remaining);
if (remaining == 0)
break; // no more to generate
}
if (unsent == 0)
r->response_buffer_sent = r->response_buffer_length = 0;
if (r->phase == PAUSE) {
if (unsent == 0)
return; // nothing to send
} else if (r->response.content_generator) {
// If the buffer is smaller than the content generator needs, and it contains no unsent
// content, then allocate a larger buffer.
if (r->response_buffer_need > r->response_buffer_size && unsent == 0) {
if (http_request_set_response_bufsize(r, r->response_buffer_need) == -1) {
WHYF("HTTP response truncated at offset=%"PRIhttp_size_t" due to insufficient buffer space",
r->response_sent);
http_request_finalise(r);
return;
}
}
// If there are some sent bytes at the start of the buffer and only a few unsent bytes, then
// move the unsent content to the start of the buffer to make more room.
if (r->response_buffer_sent > 0 && unsent < 128) {
memmove(r->response_buffer, r->response_buffer + r->response_buffer_sent, unsent);
r->response_buffer_length -= r->response_buffer_sent;
r->response_buffer_sent = 0;
}
// If there is enough unfilled room at the end of the buffer, then fill the buffer with some
// more content.
assert(r->response_buffer_length <= r->response_buffer_size);
size_t unfilled = r->response_buffer_size - r->response_buffer_length;
if (unfilled > 0 && unfilled >= r->response_buffer_need) {
// The content generator must fill or partly fill the part of the buffer we indicate and
// return the number of bytes appended. If it returns zero, it means it has no more
// content (EOF), and must not be called again. If the return value exceeds the buffer size
// we supply, it gives the amount of free space the generator needs in order to append; the
// generator will not append any bytes until that much free space is available. If returns
// -1, it means an unrecoverable error occurred, and the generator must not be called again.
struct http_content_generator_result result;
bzero(&result, sizeof result);
int ret = r->response.content_generator(r, (unsigned char *) r->response_buffer + r->response_buffer_length, unfilled, &result);
if (ret == -1) {
WHY("Content generation error, closing connection");
http_request_finalise(r);
return;
}
assert(result.generated <= unfilled);
r->response_buffer_length += result.generated;
r->response_buffer_need = result.need;
if (result.generated == 0 && result.need <= unfilled && r->phase != PAUSE) {
WHYF("HTTP response generator produced no content at offset %"PRIhttp_size_t" (ret=%d)", r->response_sent, ret);
http_request_finalise(r);
return;
}
if (r->debug_flag && *r->debug_flag)
DEBUGF("Generated HTTP %zu bytes of content, need %zu bytes of buffer (ret=%d)", result.generated, result.need, ret);
if (r->phase != PAUSE && ret == 0)
r->response.content_generator = NULL; // ensure we never invoke again
continue;
}
} else if (remaining != CONTENT_LENGTH_UNKNOWN && unsent < remaining) {
WHYF("HTTP response generator finished prematurely at offset %"PRIhttp_size_t"/%"PRIhttp_size_t" (%"PRIhttp_size_t" bytes remaining)",
r->response_sent, r->response_length, remaining);
http_request_finalise(r);
return;
} else if (unsent == 0)
break;
assert(unsent > 0);
if (remaining != CONTENT_LENGTH_UNKNOWN && unsent > remaining) {
WHYF("HTTP response overruns Content-Length (%"PRIhttp_size_t") by %"PRIhttp_size_t" bytes -- truncating",
r->response_length, unsent - remaining);
unsent = remaining;
}
sigPipeFlag = 0;
ssize_t written = write_nonblock(r->alarm.poll.fd, r->response_buffer + r->response_buffer_sent, unsent);
if (written == -1) {
if (r->debug_flag && *r->debug_flag)
DEBUG("HTTP socket write error, closing connection");
http_request_finalise(r);
return;
}
if (sigPipeFlag) {
if (r->debug_flag && *r->debug_flag)
DEBUG("Received SIGPIPE on HTTP socket write, closing connection");
http_request_finalise(r);
return;
}
// If we wrote nothing, go back to polling.
if (written == 0)
return;
r->response_sent += (size_t) written;
r->response_buffer_sent += (size_t) written;
assert(r->response_sent <= r->response_length);
assert(r->response_buffer_sent <= r->response_buffer_length);
if (r->debug_flag && *r->debug_flag)
DEBUGF("Wrote %zu bytes to HTTP socket, total %"PRIhttp_size_t", remaining=%"PRIhttp_size_t,
(size_t) written, r->response_sent, r->response_length - r->response_sent);
// Reset inactivity timer.
if (r->phase != PAUSE)
http_request_set_idle_timeout(r);
// If we wrote less than we tried, then go back to polling, otherwise keep generating content.
if ((size_t) written < (size_t) unsent)
return;
}
if (r->debug_flag && *r->debug_flag)
DEBUG("Done, closing connection");
http_request_finalise(r);
}
static void http_server_poll(struct sched_ent *alarm)
{
struct http_request *r = (struct http_request *) alarm;
if (alarm->poll.revents == 0) {
if (r->phase == PAUSE) {
r->phase = TRANSMIT;
r->alarm.poll.events = POLLOUT;
watch(&r->alarm);
http_request_set_idle_timeout(r);
} else {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Timeout, closing connection");
http_request_finalise(r);
}
}
else if (alarm->poll.revents & (POLLHUP | POLLERR)) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("Poll error (%s), closing connection", alloca_poll_events(alarm->poll.revents));
http_request_finalise(r);
}
else if (alarm->poll.revents & POLLIN) {
assert((alarm->poll.revents & POLLOUT) == 0);
http_request_receive(r); // this could change the phase to TRANSMIT
}
else if (alarm->poll.revents & POLLOUT) {
assert((alarm->poll.revents & POLLIN) == 0);
http_request_send_response(r);
}
else
abort(); // should not be any other POLL bits set
// Any of the above calls could change the phase to DONE.
if (r->phase == DONE && r->free)
r->free(r); // after this, *r is no longer valid
}
/* Copy the array of byte ranges, closing it (converting all ranges to CLOSED) using the supplied
* resource length. If a range is not satisfiable it is omitted from 'dst'. Returns the number of
* closed ranges written to 'dst'.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
unsigned http_range_close(struct http_range *dst, const struct http_range *src, unsigned nranges, http_size_t resource_length)
{
unsigned i;
unsigned ndst = 0;
for (i = 0; i != nranges; ++i) {
http_size_t first = 0;
http_size_t last = resource_length - 1;
const struct http_range *range = &src[i];
switch (range->type) {
case CLOSED:
last = range->last < resource_length ? range->last : resource_length - 1;
case OPEN:
first = range->first < resource_length ? range->first : resource_length;
break;
case SUFFIX:
first = range->last < resource_length ? resource_length - range->last : 0;
break;
default:
abort(); // not reached
}
if (first <= last)
dst[ndst++] = (struct http_range){ .type = CLOSED, .first=first, .last=last };
}
return ndst;
}
/* Return the total number of bytes represented by the given ranges which must all be CLOSED and
* valid.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
http_size_t http_range_bytes(const struct http_range *range, unsigned nranges)
{
http_size_t bytes = 0;
unsigned i;
for (i = 0; i != nranges; ++i) {
assert(range[i].type == CLOSED);
assert(range[i].last >= range[i].first);
bytes += range[i].last - range[i].first + 1;
}
return bytes;
}
/* Return appropriate message for HTTP response codes, both known and unknown.
*/
static const char *httpResultString(int response_code)
{
switch (response_code) {
case 200: return "OK";
case 201: return "Created";
case 204: return "No Content";
case 206: return "Partial Content";
case 400: return "Bad Request";
case 401: return "Unauthorized";
case 403: return "Forbidden";
case 404: return "Not Found";
case 405: return "Method Not Allowed";
case 408: return "Request Timeout";
case 409: return "Conflict";
case 411: return "Length Required";
case 414: return "Request-URI Too Long";
case 415: return "Unsupported Media Type";
case 416: return "Requested Range Not Satisfiable";
case 431: return "Request Header Fields Too Large";
case 500: return "Internal Server Error";
case 501: return "Not Implemented";
default: return (response_code <= 4) ? "Unknown status code" : "A suffusion of yellow";
}
}
static strbuf strbuf_status_body(strbuf sb, struct http_response *hr, const char *message)
{
if ( hr->header.content_type == CONTENT_TYPE_TEXT
|| (hr->header.content_type && strcmp(hr->header.content_type, CONTENT_TYPE_TEXT) == 0)
) {
hr->header.content_type = CONTENT_TYPE_TEXT;
strbuf_sprintf(sb, "%03u %s", hr->result_code, message);
unsigned i;
for (i = 0; i < NELS(hr->result_extra); ++i)
if (hr->result_extra[i].label) {
strbuf_puts(sb, "\r\n");
strbuf_puts(sb, hr->result_extra[i].label);
strbuf_puts(sb, "=");
strbuf_json_atom_as_text(sb, &hr->result_extra[i].value);
}
strbuf_puts(sb, "\r\n");
}
else if ( hr->header.content_type == CONTENT_TYPE_JSON
|| (hr->header.content_type && strcmp(hr->header.content_type, CONTENT_TYPE_JSON) == 0)
) {
hr->header.content_type = CONTENT_TYPE_JSON;
strbuf_sprintf(sb, "{\n \"http_status_code\": %u,\n \"http_status_message\": ", hr->result_code);
strbuf_json_string(sb, message);
unsigned i;
for (i = 0; i < NELS(hr->result_extra); ++i)
if (hr->result_extra[i].label) {
strbuf_puts(sb, ",\n ");
strbuf_json_string(sb, hr->result_extra[i].label);
strbuf_puts(sb, ": ");
strbuf_json_atom(sb, &hr->result_extra[i].value);
}
strbuf_puts(sb, "\n}");
}
else {
hr->header.content_type = CONTENT_TYPE_HTML;
strbuf_sprintf(sb, "<html>\n<h1>%03u %s</h1>", hr->result_code, message);
unsigned i;
for (i = 0; i < NELS(hr->result_extra); ++i)
if (hr->result_extra[i].label) {
strbuf_puts(sb, "\n<dl><dt>");
strbuf_html_escape(sb, hr->result_extra[i].label, strlen(hr->result_extra[i].label));
strbuf_puts(sb, "</dt><dd>");
strbuf_json_atom_as_html(sb, &hr->result_extra[i].value);
strbuf_puts(sb, "</dd></dl>");
}
strbuf_puts(sb, "\n</html>");
}
return sb;
}
/* Render the HTTP response into the current response buffer. Return 1 if it fits, 0 if it does
* not. The buffer response_pointer may be NULL, in which case no response is rendered, but the
* content_length is still computed
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
static int _render_response(struct http_request *r)
{
struct http_response hr = r->response;
assert(hr.result_code >= 100);
assert(hr.result_code < 600);
// Status code 401 must be accompanied by a WWW-Authenticate header.
if (hr.result_code == 401)
assert(hr.header.www_authenticate.scheme != NOAUTH);
const char *result_string = httpResultString(hr.result_code);
strbuf sb = strbuf_local(r->response_buffer, r->response_buffer_size);
// Cannot specify both static (pre-rendered) content AND generated content.
assert(!(hr.content && hr.content_generator));
if (hr.content || hr.content_generator) {
// With static (pre-rendered) content, the content length is mandatory (so we know how much data
// follows the 'hr.content' pointer. Generated content will generally not send a Content-Length
// header, nor send partial content, but they might.
if (hr.content)
assert(hr.header.content_length != CONTENT_LENGTH_UNKNOWN);
// Ensure that all partial content fields are consistent. If content length or resource length
// are unknown, there can be no range field.
if ( hr.header.content_length != CONTENT_LENGTH_UNKNOWN
&& hr.header.resource_length != CONTENT_LENGTH_UNKNOWN
) {
assert(hr.header.content_length <= hr.header.resource_length);
assert(hr.header.content_range_start + hr.header.content_length <= hr.header.resource_length);
} else {
assert(hr.header.content_range_start == 0);
}
// Convert a 200 status code into 206 if only partial content is being sent. This saves page
// handlers having to decide between 200 (OK) and 206 (Partial Content), they can just set the
// content and resource length fields and pass 200 to http_request_response_static(), and this
// logic will change it to 206 if appropriate.
if ( hr.header.content_length != CONTENT_LENGTH_UNKNOWN
&& hr.header.resource_length != CONTENT_LENGTH_UNKNOWN
&& hr.header.content_length > 0
&& hr.header.content_length < hr.header.resource_length
) {
if (hr.result_code == 200)
hr.result_code = 206; // Partial Content
}
} else {
// If no content is supplied at all, then render a standard, short body based solely on result
// code, consistent with the response Content-Type if already set (HTML if not set).
assert(hr.header.content_length == CONTENT_LENGTH_UNKNOWN);
assert(hr.header.resource_length == CONTENT_LENGTH_UNKNOWN);
assert(hr.header.content_range_start == 0);
assert(hr.result_code != 206);
strbuf cb;
STRBUF_ALLOCA_FIT(cb, 40 + strlen(result_string), (strbuf_status_body(cb, &hr, result_string)));
hr.content = strbuf_str(cb);
hr.header.content_length = strbuf_len(cb);
hr.header.resource_length = hr.header.content_length;
hr.header.content_range_start = 0;
}
assert(hr.header.content_type != NULL);
assert(hr.header.content_type[0]);
strbuf_sprintf(sb, "HTTP/1.0 %03u %s\r\n", hr.result_code, result_string);
strbuf_sprintf(sb, "Content-Type: %s", hr.header.content_type);
if (hr.header.boundary) {
strbuf_puts(sb, "; boundary=");
if (strchr(hr.header.boundary, '"') || strchr(hr.header.boundary, '\\'))
strbuf_append_quoted_string(sb, hr.header.boundary);
else
strbuf_puts(sb, hr.header.boundary);
}
strbuf_puts(sb, "\r\n");
if (hr.result_code == 206) {
// Must only use result code 206 (Partial Content) if the content is in fact less than the whole
// resource length.
assert(hr.header.content_length != CONTENT_LENGTH_UNKNOWN);
assert(hr.header.resource_length != CONTENT_LENGTH_UNKNOWN);
assert(hr.header.content_length > 0);
assert(hr.header.content_length < hr.header.resource_length);
strbuf_sprintf(sb,
"Content-Range: bytes %"PRIhttp_size_t"-%"PRIhttp_size_t"/%"PRIhttp_size_t"\r\n",
hr.header.content_range_start,
hr.header.content_range_start + hr.header.content_length - 1,
hr.header.resource_length
);
}
if (hr.header.content_length != CONTENT_LENGTH_UNKNOWN)
strbuf_sprintf(sb, "Content-Length: %"PRIhttp_size_t"\r\n", hr.header.content_length);
if (hr.header.allow_origin)
strbuf_sprintf(sb, "Access-Control-Allow-Origin: %s\r\n", hr.header.allow_origin);
if (hr.header.allow_methods)
strbuf_sprintf(sb, "Access-Control-Allow-Methods: %s\r\n", hr.header.allow_methods);
if (hr.header.allow_headers)
strbuf_sprintf(sb, "Access-Control-Allow-Headers: %s\r\n", hr.header.allow_headers);
const char *scheme = NULL;
switch (hr.header.www_authenticate.scheme) {
case NOAUTH: break;
case BASIC: scheme = "Basic"; break;
}
if (scheme) {
assert(hr.result_code == 401);
strbuf_sprintf(sb, "WWW-Authenticate: %s realm=", scheme);
strbuf_append_quoted_string(sb, hr.header.www_authenticate.realm);
strbuf_puts(sb, "\r\n");
}
if (r->render_extra_headers)
r->render_extra_headers(r, sb);
assert(strcmp(strbuf_substr(sb, -2), "\r\n") == 0);
strbuf_puts(sb, "\r\n");
if (hr.header.content_length != CONTENT_LENGTH_UNKNOWN)
r->response_length = strbuf_count(sb) + hr.header.content_length;
else
r->response_length = CONTENT_LENGTH_UNKNOWN;
r->response_buffer_need = strbuf_count(sb) + 1; // the header and the strbuf terminating NUL
if (hr.content) {
assert(r->response_length != CONTENT_LENGTH_UNKNOWN);
if (r->response_buffer_need < r->response_length)
r->response_buffer_need = r->response_length;
} else
assert(hr.content_generator);
if (r->response_buffer_size < r->response_buffer_need)
return 0; // doesn't fit
assert(!strbuf_overrun(sb));
if (hr.content) {
bcopy(hr.content, strbuf_end(sb), hr.header.content_length);
r->response_buffer_length = r->response_length;
} else {
r->response_buffer_length = strbuf_count(sb);
}
r->response_buffer_sent = 0;
return 1;
}
/* Returns with the length of the rendered response in r->response_length. If the rendered response
* did not fit into any available buffer, then returns with r->response_buffer == NULL, otherwise
* r->response_buffer points to the rendered response.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
static void http_request_render_response(struct http_request *r)
{
// If there is no response buffer allocated yet, use the available part of the in-struct buffer.
http_request_set_response_bufsize(r, 1);
// Try rendering the response into the existing buffer. This will discover the length of the
// rendered headers, so after this step, whether or not the buffer was overrun, we know the total
// length of the response.
if (!_render_response(r)) {
// If the static response did not fit into the existing buffer, then allocate a large buffer
// from the heap and try rendering again.
if (http_request_set_response_bufsize(r, r->response_buffer_need) == -1)
WHY("Cannot render HTTP response, out of memory");
else if (!_render_response(r))
FATAL("Re-render of HTTP response overflowed buffer");
}
}
static size_t http_request_drain(struct http_request *r)
{
assert(r->phase == RECEIVE);
char buf[8192];
size_t drained = 0;
ssize_t bytes;
while ((bytes = http_request_read(r, buf, sizeof buf)) != -1 && bytes != 0)
drained += (size_t) bytes;
return drained;
}
static void http_request_start_response(struct http_request *r)
{
assert(r->phase == RECEIVE);
_release_reserved(r);
if (r->response.content || r->response.content_generator) {
assert(r->response.header.content_type != NULL);
assert(r->response.header.content_type[0]);
}
// If HTTP responses are disabled (eg, for testing purposes) then skip all response construction
// and close the connection.
if (r->disable_tx_flag && *r->disable_tx_flag) {
INFO("HTTP transmit disabled, closing connection");
http_request_finalise(r);
return;
}
// Drain the rest of the request that has not been received yet (eg, if sending an error response
// provoked while parsing the early part of a partially-received request). If a read error
// occurs, the connection is closed so the phase changes to DONE.
http_request_drain(r);
if (r->phase != RECEIVE)
return;
// Ensure conformance to HTTP standards.
if (r->response.result_code == 401 && r->response.header.www_authenticate.scheme == NOAUTH) {
WHY("HTTP 401 response missing WWW-Authenticate header, sending 500 Server Error instead");
r->response.result_code = 500;
r->response.content = NULL;
r->response.content_generator = NULL;
}
// If the response cannot be rendered, then render a 500 Server Error instead. If that fails,
// then just close the connection.
http_request_render_response(r);
if (r->response_buffer == NULL) {
WARN("Cannot render HTTP response, sending 500 Server Error instead");
r->response.result_code = 500;
r->response.content = NULL;
r->response.content_generator = NULL;
http_request_render_response(r);
if (r->response_buffer == NULL) {
WHY("Cannot render HTTP 500 Server Error response, closing connection");
http_request_finalise(r);
return;
}
}
r->response_buffer_need = 0;
r->response_sent = 0;
if (r->debug_flag && *r->debug_flag)
DEBUGF("Sending HTTP response: %s", alloca_toprint(160, (const char *)r->response_buffer, r->response_buffer_length));
r->phase = TRANSMIT;
r->alarm.poll.events = POLLOUT;
watch(&r->alarm);
}
void http_request_pause_response(struct http_request *r, time_ms_t until)
{
if (r->debug_flag && *r->debug_flag)
DEBUGF("Pausing response for %.3f sec", (double)(until - gettime_ms()) / 1000.0);
assert(r->phase == TRANSMIT);
r->phase = PAUSE;
r->alarm.alarm = until;
r->alarm.deadline = until + r->idle_timeout;
unwatch(&r->alarm);
unschedule(&r->alarm);
schedule(&r->alarm);
}
/* Start sending a static (pre-computed) response back to the client. The response's Content-Type
* is set by the 'mime_type' parameter (in the standard format "type/subtype"). The response's
* content is set from the 'body' and 'bytes' parameters, which need not point to persistent data,
* ie, the memory pointed to by 'body' is no longer referenced once this function returns.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
void http_request_response_static(struct http_request *r, int result, const char *mime_type, const char *body, uint64_t bytes)
{
assert(r->phase == RECEIVE);
assert(mime_type != NULL);
assert(mime_type[0]);
r->response.result_code = result;
r->response.header.content_type = mime_type;
r->response.header.content_range_start = 0;
r->response.header.content_length = r->response.header.resource_length = bytes;
r->response.content = body;
r->response.content_generator = NULL;
http_request_start_response(r);
}
void http_request_response_generated(struct http_request *r, int result, const char *mime_type, HTTP_CONTENT_GENERATOR generator)
{
assert(r->phase == RECEIVE);
assert(mime_type != NULL);
assert(mime_type[0]);
r->response.result_code = result;
r->response.header.content_type = mime_type;
r->response.content = NULL;
r->response.content_generator = generator;
http_request_start_response(r);
}
/* Start sending a short response back to the client. The result code must be either a success
* (2xx), redirection (3xx) or client error (4xx) or server error (5xx) code. The 'message'
* argument may be a bare message which is enclosed in an HTML envelope to form the response
* content, so it may contain HTML markup. If the 'message' argument is NULL, then the response
* content is generated automatically from the result code.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
void http_request_simple_response(struct http_request *r, uint16_t result, const char *message)
{
assert(r->phase == RECEIVE);
r->response.result_code = result;
r->response.header.content_range_start = 0;
strbuf h = NULL;
if (message)
STRBUF_ALLOCA_FIT(h, 40 + strlen(message), (strbuf_status_body(h, &r->response, message)));
if (h) {
r->response.header.resource_length = r->response.header.content_length = strbuf_len(h);
r->response.content = strbuf_str(h);
}
r->response.content_generator = NULL;
http_request_start_response(r);
}
int generate_http_content_from_strbuf_chunks(
struct http_request *r,
char *buf,
size_t bufsz,
struct http_content_generator_result *result,
HTTP_CONTENT_GENERATOR_STRBUF_CHUNKER *chunker
)
{
assert(bufsz > 0);
strbuf b = strbuf_local((char *)buf, bufsz);
int ret;
while ((ret = chunker(r, b)) != -1) {
if (strbuf_overrun(b)) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("overrun by %zu bytes", strbuf_count(b) - strbuf_len(b));
result->need = strbuf_count(b) + 1 - result->generated;
break;
}
result->generated = strbuf_len(b);
if (ret == 0)
break;
}
return ret;
}
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