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serval-dna/http_server.c
Andrew Bettison 9b64bb87e0 Uniform copyright notices 
Added some missing copyright/license block comments
2013-12-04 17:15:36 +10:30

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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.h"
#include "conf.h"
#include "http_server.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
};
static struct profile_total http_server_stats = {
.name = "http_server_poll",
};
#define DEBUG_DUMP_PARSED(r) do { \
if (config.debug.httpd) \
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.httpd) \
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_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;
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->received = r->end = r->parsed = r->cursor = r->buffer;
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 + r->idle_timeout;
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->received < bufe);
size_t rbufsiz = bufe - r->received;
if (bufsiz <= rbufsiz) {
http_request_free_response_buffer(r);
r->response_buffer = (char *) r->received;
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 const char * _reserve(struct http_request *r, struct substring str)
{
char *reslim = r->buffer + sizeof r->buffer - 1024; // always leave this much unreserved space
assert(r->received <= reslim);
size_t len = str.end - str.start;
size_t siz = len + 1;
if (r->received + siz > reslim) {
r->response.result_code = 414;
return NULL;
}
if (r->received + 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 NULL;
}
char *ret = (char *) r->received;
if (ret != str.start)
memmove(ret, str.start, len);
ret[len] = '\0';
r->received += siz;
assert(r->received <= r->parsed);
return ret;
}
static const char * _reserve_str(struct http_request *r, const char *str)
{
struct substring sub = { .start = str, .end = str + strlen(str) };
return _reserve(r, sub);
}
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 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, &r->cursor);
}
static inline int _parse_uint(struct http_request *r, unsigned int *uintp)
{
return !_run_out(r) && isdigit(*r->cursor) && str_to_uint(r->cursor, 10, uintp, &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)) {
const 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;
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, &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)
{
const 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;
if ( (auth->credentials.basic.user = _reserve_str(r, auth->credentials.basic.user)) == NULL
|| (auth->credentials.basic.password = _reserve_str(r, auth->credentials.basic.password)) == NULL
)
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 ((r->path = _reserve(r, path)) == NULL)
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);
unsigned major, minor;
if (!( _skip_literal(r, "HTTP/")
&& _parse_uint(r, &major)
&& major > 0 && major < UINT8_MAX
&& _skip_literal(r, ".")
&& _parse_uint(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;
}
const 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;
}
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) {
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_type.type == NULL) {
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;
}
/* 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)) {
const 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;
}
static void 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:
if (r->form_data.handle_mime_part_end) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("handle_mime_part_end()");
r->form_data.handle_mime_part_end(r);
}
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;
if (r->form_data.handle_mime_part_start) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("handle_mime_part_start()");
r->form_data.handle_mime_part_start(r);
}
} else
r->form_data_state = EPILOGUE;
}
/* 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 a variety of use cases.
*
* @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.httpd)
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.httpd)
DEBUGF("PREAMBLE");
const char *start = r->parsed;
for (; at_start || _skip_to_crlf(r); at_start = 0) {
const char *end_preamble = r->cursor;
int b;
if ((b = _skip_mime_boundary(r))) {
assert(end_preamble >= r->parsed);
if (r->form_data.handle_mime_preamble && end_preamble != r->parsed) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("handle_mime_preamble(%s length=%zu)",
alloca_toprint(50, r->parsed, end_preamble - r->parsed), end_preamble - r->parsed);
r->form_data.handle_mime_preamble(r, r->parsed, end_preamble - r->parsed);
}
_rewind_crlf(r);
_commit(r);
http_request_form_data_start_part(r, b);
return 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);
if (r->parsed > start && r->form_data.handle_mime_preamble) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("handle_mime_preamble(%s length=%zu)",
alloca_toprint(50, start, r->parsed - start), r->parsed - start);
r->form_data.handle_mime_preamble(r, start, r->parsed - start);
}
}
return 100; // need more data
case HEADER: {
if (config.debug.httpd)
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;
}
const char *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)
);
r->form_data.handle_mime_part_header(r, &r->part_header);
}
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.
http_request_form_data_start_part(r, b);
return 0;
}
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);
const char *value = r->cursor;
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 Content-Length: %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 Content-Type: %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 Content-Disposition: %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: %s", alloca_str_toprint(labelstr), alloca_toprint(-1, value, value - r->cursor));
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.httpd)
DEBUGF("BODY");
const char *start = r->parsed;
while (_skip_to_crlf(r)) {
int b;
const 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;
if (end_body > start && r->form_data.handle_mime_body) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("handle_mime_body(%s length=%zu)", alloca_toprint(80, start, end_body - start), end_body - start);
r->form_data.handle_mime_body(r, start, end_body - start); // excluding CRLF at end
}
http_request_form_data_start_part(r, b);
return 0;
}
}
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;
if (r->parsed > start && r->form_data.handle_mime_body) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("handle_mime_body(%s length=%zu)", alloca_toprint(80, start, r->parsed - start), r->parsed - start);
r->form_data.handle_mime_body(r, start, r->parsed - start);
}
return 100; // need more data
case EPILOGUE:
if (config.debug.httpd)
DEBUGF("EPILOGUE");
r->cursor = r->end;
if (r->form_data.handle_mime_epilogue && r->cursor != r->parsed) {
if (r->debug_flag && *r->debug_flag)
DEBUGF("handle_mime_epilogue(%s length=%zu)",
alloca_toprint(50, r->parsed, r->cursor - r->parsed), r->cursor - r->parsed);
r->form_data.handle_mime_epilogue(r, r->parsed, r->cursor - r->parsed);
}
_commit(r);
assert(_run_out(r));
if (_end_of_content(r))
return 0; // done
return 100; // need more data
}
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 >= 300)
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)
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 (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 (r->phase == RECEIVE && (alarm->poll.revents & POLLIN))
http_request_receive(r); // this could change the phase to TRANSMIT
if (r->phase == TRANSMIT && (alarm->poll.revents & POLLOUT))
http_request_send_response(r);
}
// 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 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 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";
}
}
/* 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.
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(100 + strlen(result_string));
strbuf_sprintf(cb, "<html><h1>%03u %s</h1></html>", hr.result_code, result_string);
hr.content = strbuf_str(cb);
hr.header.content_type = "text/html";
hr.header.resource_length = hr.header.content_length = strbuf_len(cb);
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);
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");
}
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);
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 'body' 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 'body' 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 *body)
{
assert(r->phase == RECEIVE);
strbuf h = NULL;
if (body) {
size_t html_len = strlen(body) + 40;
h = strbuf_alloca(html_len);
strbuf_sprintf(h, "<html><h1>%03u %s</h1></html>", result, body);
}
r->response.result_code = result;
r->response.header.content_type = "text/html";
r->response.header.content_range_start = 0;
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);
}
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