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637 lines
22 KiB
C
637 lines
22 KiB
C
/*
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Serval Distributed Numbering Architecture (DNA)
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Copyright (C) 2012 Paul Gardner-Stephen
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; either version 2
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of the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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/*
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Portions Copyright (C) 2013 Petter Reinholdtsen
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Some rights reserved
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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1. Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the
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distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <assert.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <sys/stat.h>
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#include <signal.h>
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#include "sighandlers.h"
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#include "serval.h"
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#include "conf.h"
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#include "str.h"
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#include "uri.h"
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#include "strbuf.h"
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#include "strbuf_helpers.h"
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#include "dataformats.h"
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#include "overlay_address.h"
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/*
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The challenge with making an interface for calling an external program to
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resolve a DID into a URI is that it really should be asynchronous, so that
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servald can't pause due to delays in looking up DIDs by helper applications.
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This can be partially mitigated by having a cache, so that at least for repeated
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requests the helper doesn't need to be called each time. This is very important
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because the DNA protocol relies on pre-emptive retries to ensure reception of
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a request over a lossy network.
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The second part of the solution is to create an asynchronous queue for requests,
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by passing them via file descriptor to a single persistent instance of the DNA
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helper application, and polling the output of that application for results, and
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then passing them out to their destinations. This ensures that the process is
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asynchronous and non-blocking, regardless of how much time the helper application
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requires. Then the helper will just be another file descriptor to poll in the
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main loop.
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*/
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int
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parseDnaReply(const char *buf, size_t len, char *token, char *did, char *name, char *uri, const char **bufp)
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{
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/* Replies look like: TOKEN|URI|DID|NAME| where TOKEN is usually a hex SID */
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const char *b = buf;
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const char *e = buf + len;
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char *p, *q;
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for (p = token, q = token + SID_STRLEN; b != e && *b != '|' && p != q; ++p, ++b)
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*p = *b;
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*p = '\0';
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if (b == e || *b++ != '|')
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return 0;
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for (p = uri, q = uri + 511; b != e && *b != '|' && p != q; ++p, ++b)
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*p = *b;
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*p = '\0';
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if (b == e || *b++ != '|')
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return 0;
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for (p = did, q = did + DID_MAXSIZE; b != e && *b != '|' && p != q; ++p, ++b)
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*p = *b;
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*p = '\0';
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if (b == e || *b++ != '|')
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return 0;
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for (p = name, q = name + 63; b != e && *b != '|' && p != q; ++p, ++b)
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*p = *b;
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*p = '\0';
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if (b == e || *b++ != '|')
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return 0;
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if (bufp)
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*bufp = b;
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return 1;
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}
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static pid_t dna_helper_pid = -1;
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static int dna_helper_stdin = -1;
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static int dna_helper_stdout = -1;
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static int dna_helper_stderr = -1;
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static int dna_helper_started = 0;
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#define DECLARE_SCHED_ENT(FUNCTION, VARIABLE) \
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static void FUNCTION(struct sched_ent *alarm); \
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static struct profile_total VARIABLE##_timing={.name="" #FUNCTION "",._next=NULL,._initialised=0,.max_time=0,.total_time=0,.child_time=0,.calls=0}; \
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static struct sched_ent VARIABLE = {.function = FUNCTION, .stats = & VARIABLE##_timing, .poll={.fd=-1}};
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DECLARE_SCHED_ENT(monitor_requests, sched_requests);
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DECLARE_SCHED_ENT(monitor_replies, sched_replies);
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DECLARE_SCHED_ENT(monitor_errors, sched_errors);
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DECLARE_SCHED_ENT(harvester, sched_harvester);
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DECLARE_SCHED_ENT(restart_delayer, sched_restart);
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DECLARE_SCHED_ENT(reply_timeout, sched_timeout);
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// This buffer must hold "SID|DID|\n\0"
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static char request_buffer[SID_STRLEN + DID_MAXSIZE + 4];
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static char *request_bufptr = NULL;
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static char *request_bufend = NULL;
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static struct subscriber *request_source = NULL;
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static mdp_port_t request_port = 0;
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static char request_did[DID_MAXSIZE + 1];
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static int awaiting_reply = 0;
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static int discarding_until_nl = 0;
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static char reply_buffer[2048];
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static char *reply_bufend = NULL;
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static void
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dna_helper_close_pipes()
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{
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if (dna_helper_stdin != -1) {
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DEBUGF(dnahelper, "DNAHELPER closing stdin pipe fd=%d", dna_helper_stdin);
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close(dna_helper_stdin);
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dna_helper_stdin = -1;
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}
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if (sched_requests.poll.fd != -1) {
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unwatch(&sched_requests);
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sched_requests.poll.fd = -1;
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}
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if (dna_helper_stdout != -1) {
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DEBUGF(dnahelper, "DNAHELPER closing stdout pipe fd=%d", dna_helper_stdout);
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close(dna_helper_stdout);
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dna_helper_stdout = -1;
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}
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if (sched_replies.poll.fd != -1) {
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unwatch(&sched_replies);
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sched_replies.poll.fd = -1;
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}
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if (dna_helper_stderr != -1) {
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DEBUGF(dnahelper, "DNAHELPER closing stderr pipe fd=%d", dna_helper_stderr);
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close(dna_helper_stderr);
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dna_helper_stderr = -1;
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}
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if (sched_errors.poll.fd != -1) {
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unwatch(&sched_errors);
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sched_errors.poll.fd = -1;
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}
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}
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int
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dna_helper_start()
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{
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dna_helper_shutdown();
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if (!config.dna.helper.executable[0]) {
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INFO("DNAHELPER none configured");
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return 0;
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}
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const char *mysid = alloca_tohex_sid_t(get_my_subscriber()->sid);
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int stdin_fds[2], stdout_fds[2], stderr_fds[2];
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if (pipe(stdin_fds) == -1)
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return WHY_perror("pipe");
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if (pipe(stdout_fds) == -1) {
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WHY_perror("pipe");
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close(stdin_fds[0]);
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close(stdin_fds[1]);
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return -1;
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}
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if (pipe(stderr_fds) == -1) {
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WHY_perror("pipe");
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close(stdin_fds[0]);
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close(stdin_fds[1]);
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close(stdout_fds[0]);
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close(stdout_fds[1]);
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return -1;
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}
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// Construct argv[] for execv() and log messages.
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const char *argv[config.dna.helper.argv.ac + 2];
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argv[0] = config.dna.helper.executable;
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unsigned i;
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for (i = 0; i < config.dna.helper.argv.ac; ++i)
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argv[i + 1] = config.dna.helper.argv.av[i].value;
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argv[i + 1] = NULL;
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strbuf argv_sb = strbuf_append_argv(strbuf_alloca(1024), config.dna.helper.argv.ac + 1, argv);
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switch (dna_helper_pid = fork()) {
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case 0:
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/* Child, should exec() to become helper after installing file descriptors. */
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close_log_file();
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setenv("MYSID", mysid, 1);
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signal(SIGTERM, SIG_DFL);
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close(stdin_fds[1]);
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close(stdout_fds[0]);
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close(stderr_fds[0]);
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if (dup2(stderr_fds[1], 2) == -1 || dup2(stdout_fds[1], 1) == -1 || dup2(stdin_fds[0], 0) == -1) {
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LOG_perror(LOG_LEVEL_FATAL, "dup2");
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_exit(-1);
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}
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{
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execv(config.dna.helper.executable, (char **)argv);
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LOGF_perror(LOG_LEVEL_FATAL, "execv(%s, [%s])",
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alloca_str_toprint(config.dna.helper.executable),
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strbuf_str(argv_sb)
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);
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}
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do { _exit(-1); } while (1);
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break;
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case -1:
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/* fork failed */
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WHY_perror("fork");
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close(stdin_fds[0]);
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close(stdin_fds[1]);
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close(stdout_fds[0]);
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close(stdout_fds[1]);
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close(stderr_fds[0]);
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close(stderr_fds[1]);
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return -1;
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default:
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/* Parent, should put file descriptors into place for use */
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close(stdin_fds[0]);
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close(stdout_fds[1]);
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close(stderr_fds[1]);
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dna_helper_started = 0;
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dna_helper_stdin = stdin_fds[1];
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dna_helper_stdout = stdout_fds[0];
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dna_helper_stderr = stderr_fds[0];
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INFOF("STARTED DNA HELPER pid=%u stdin=%d stdout=%d stderr=%d executable=%s argv=[%s]",
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dna_helper_pid,
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dna_helper_stdin,
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dna_helper_stdout,
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dna_helper_stderr,
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alloca_str_toprint(config.dna.helper.executable),
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strbuf_str(argv_sb)
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);
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sched_replies.poll.fd = dna_helper_stdout;
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sched_replies.poll.events = POLLIN;
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sched_errors.poll.fd = dna_helper_stderr;
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sched_errors.poll.events = POLLIN;
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sched_requests.poll.fd = -1;
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sched_requests.poll.events = POLLOUT;
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sched_harvester.alarm = gettime_ms() + 1000;
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sched_harvester.deadline = sched_harvester.alarm + 1000;
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reply_bufend = reply_buffer;
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discarding_until_nl = 0;
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awaiting_reply = 0;
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watch(&sched_replies);
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watch(&sched_errors);
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schedule(&sched_harvester);
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return 0;
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}
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return -1;
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}
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static int
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dna_helper_kill()
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{
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if (awaiting_reply) {
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unschedule(&sched_timeout);
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awaiting_reply = 0;
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}
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if (dna_helper_pid > 0) {
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DEBUGF(dnahelper, "DNAHELPER sending SIGTERM to pid=%d", dna_helper_pid);
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if (kill(dna_helper_pid, SIGTERM) == -1)
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WHYF_perror("kill(%d, SIGTERM)", dna_helper_pid);
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// The process is wait()ed for in dna_helper_monitor() so that we do not block here.
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return 1;
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}
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return 0;
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}
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static int
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dna_helper_harvest(int blocking)
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{
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if (dna_helper_pid > 0) {
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if (blocking)
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DEBUGF(dnahelper, "DNAHELPER waiting for pid=%d to die", dna_helper_pid);
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int status;
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pid_t pid = waitpid(dna_helper_pid, &status, blocking ? 0 : WNOHANG);
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if (pid == dna_helper_pid) {
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strbuf b = strbuf_alloca(80);
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INFOF("DNAHELPER process pid=%u %s", pid, strbuf_str(strbuf_append_exit_status(b, status)));
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unschedule(&sched_harvester);
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dna_helper_pid = -1;
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if (awaiting_reply) {
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unschedule(&sched_timeout);
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awaiting_reply = 0;
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}
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return 1;
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} else if (pid == -1) {
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return WHYF_perror("waitpid(%d, %s)", dna_helper_pid, blocking ? "0" : "WNOHANG");
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} else if (pid) {
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return WHYF("waitpid(%d, %s) returned %d", dna_helper_pid, blocking ? "0" : "WNOHANG", pid);
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}
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}
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return 0;
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}
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int dna_helper_shutdown()
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{
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DEBUG(dnahelper, "DNAHELPER shutting down");
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dna_helper_close_pipes();
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switch (dna_helper_kill()) {
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case -1:
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return -1;
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case 0:
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return 0;
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default:
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return dna_helper_harvest(1);
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}
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}
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static void monitor_requests(struct sched_ent *alarm)
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{
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DEBUGF(dnahelper, "sched_requests.poll.fd=%d .revents=%s",
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sched_requests.poll.fd,
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strbuf_str(strbuf_append_poll_events(strbuf_alloca(40), sched_requests.poll.revents))
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);
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assert(alarm == &sched_requests);
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// On Linux, poll(2) returns ERR when the remote reader dies. On Mac OS X, poll(2) returns NVAL,
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// which is documented to mean the file descriptor is not open, but testing revealed that in this
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// case it is still open. See issue #5.
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if (sched_requests.poll.revents & (POLLHUP | POLLERR | POLLNVAL)) {
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DEBUGF(dnahelper, "DNAHELPER closing stdin fd=%d", dna_helper_stdin);
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close(dna_helper_stdin);
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dna_helper_stdin = -1;
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unwatch(&sched_requests);
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sched_requests.poll.fd = -1;
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dna_helper_kill();
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}
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else if (sched_requests.poll.revents & POLLOUT) {
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if (request_bufptr) {
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if (request_bufptr < request_bufend) {
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size_t remaining = request_bufend - request_bufptr;
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sigPipeFlag = 0;
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ssize_t written = write_nonblock(dna_helper_stdin, request_bufptr, remaining);
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if (sigPipeFlag) {
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/* Broken pipe is probably due to a dead helper, but make sure the helper is dead, just to be
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sure. It will be harvested at the next harvester() timeout, and restarted on the first
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request that arrives after a suitable pause has elapsed. Losing the current request is not
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a big problem, because DNA preemptively retries.
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*/
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INFO("DNAHELPER got SIGPIPE on write -- stopping process");
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dna_helper_kill();
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} else if (written > 0) {
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DEBUGF(dnahelper, "DNAHELPER wrote request %s", alloca_toprint(-1, request_bufptr, written));
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request_bufptr += written;
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}
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}
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if (request_bufptr >= request_bufend) {
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// Request sent successfully. Start watching for reply.
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request_bufptr = request_bufend = NULL;
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awaiting_reply = 1;
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sched_timeout.alarm = gettime_ms() + 1500;
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sched_timeout.deadline = sched_timeout.alarm + 3000;
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schedule(&sched_timeout);
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}
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}
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// If no request to send, stop monitoring the helper's stdin pipe.
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if (!request_bufptr) {
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unwatch(&sched_requests);
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sched_requests.poll.fd = -1;
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}
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}
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}
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static char *srv_strnstr(char *haystack, size_t haystack_len, const char *needle)
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{
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size_t needle_len = strlen(needle);
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for (; haystack_len >= needle_len; ++haystack, --haystack_len) {
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if (strncmp(haystack, needle, needle_len) == 0)
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return haystack;
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}
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return NULL;
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}
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void handle_reply_line(const char *bufp, size_t len)
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{
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if (!dna_helper_started) {
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if (len == 8 && strncmp(bufp, "STARTED\n", 8) == 0) {
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DEBUGF(dnahelper, "DNAHELPER got STARTED ACK");
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dna_helper_started = 1;
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// Start sending request if there is one pending.
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if (request_bufptr) {
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sched_requests.poll.fd = dna_helper_stdin;
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watch(&sched_requests);
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}
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} else {
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WHYF("DNAHELPER malformed start ACK %s", alloca_toprint(-1, bufp, len));
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dna_helper_kill();
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}
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} else if (awaiting_reply) {
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if (len == 5 && strncmp(bufp, "DONE\n", 5) == 0) {
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DEBUG(dnahelper, "DNAHELPER reply DONE");
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unschedule(&sched_timeout);
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awaiting_reply = 0;
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} else {
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char sidhex[SID_STRLEN + 1];
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char did[DID_MAXSIZE + 1];
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char name[64];
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char uri[512];
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const char *replyend = NULL;
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if (!parseDnaReply(bufp, len, sidhex, did, name, uri, &replyend))
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WHYF("DNAHELPER reply %s invalid -- ignored", alloca_toprint(-1, bufp, len));
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else if (uri[0] == '\0')
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WHYF("DNAHELPER reply %s contains empty URI -- ignored", alloca_toprint(-1, bufp, len));
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else if (!str_is_uri(uri))
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WHYF("DNAHELPER reply %s contains invalid URI -- ignored", alloca_toprint(-1, bufp, len));
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else if (sidhex[0] == '\0')
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WHYF("DNAHELPER reply %s contains empty token -- ignored", alloca_toprint(-1, bufp, len));
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else if (!str_is_subscriber_id(sidhex))
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WHYF("DNAHELPER reply %s contains invalid token -- ignored", alloca_toprint(-1, bufp, len));
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else if (strncmp(sidhex, request_buffer, SID_STRLEN) != 0)
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WHYF("DNAHELPER reply %s contains mismatched token -- ignored", alloca_toprint(-1, bufp, len));
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else if (did[0] == '\0')
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WHYF("DNAHELPER reply %s contains empty DID -- ignored", alloca_toprint(-1, bufp, len));
|
|
else if (!str_is_did(did))
|
|
WHYF("DNAHELPER reply %s contains invalid DID -- ignored", alloca_toprint(-1, bufp, len));
|
|
else if (strcmp(did, request_did) != 0)
|
|
WHYF("DNAHELPER reply %s contains mismatched DID -- ignored", alloca_toprint(-1, bufp, len));
|
|
else if (*replyend != '\n')
|
|
WHYF("DNAHELPER reply %s contains spurious trailing chars -- ignored", alloca_toprint(-1, bufp, len));
|
|
else {
|
|
DEBUGF(dnahelper, "DNAHELPER reply %s", alloca_toprint(-1, bufp, len));
|
|
overlay_mdp_dnalookup_reply(request_source, request_port, get_my_subscriber(), uri, did, name);
|
|
}
|
|
}
|
|
} else {
|
|
WARNF("DNAHELPER spurious output %s -- ignored", alloca_toprint(-1, bufp, len));
|
|
}
|
|
}
|
|
|
|
static void monitor_replies(struct sched_ent *alarm)
|
|
{
|
|
DEBUGF(dnahelper, "sched_replies.poll.fd=%d .revents=%s",
|
|
sched_replies.poll.fd,
|
|
strbuf_str(strbuf_append_poll_events(strbuf_alloca(40), sched_replies.poll.revents))
|
|
);
|
|
assert(alarm == &sched_replies);
|
|
if (sched_replies.poll.revents & POLLIN) {
|
|
size_t remaining = reply_buffer + sizeof reply_buffer - reply_bufend;
|
|
ssize_t nread = read_nonblock(sched_replies.poll.fd, reply_bufend, remaining);
|
|
if (nread > 0) {
|
|
char *bufp = reply_buffer;
|
|
char *readp = reply_bufend;
|
|
reply_bufend += nread;
|
|
char *nl;
|
|
while (nread > 0 && (nl = srv_strnstr(readp, nread, "\n"))) {
|
|
size_t len = nl - bufp + 1;
|
|
if (discarding_until_nl) {
|
|
DEBUGF(dnahelper, "Discarding %s", alloca_toprint(-1, bufp, len));
|
|
discarding_until_nl = 0;
|
|
} else {
|
|
handle_reply_line(bufp, len);
|
|
}
|
|
readp = bufp = nl + 1;
|
|
nread = reply_bufend - readp;
|
|
}
|
|
if (bufp != reply_buffer) {
|
|
size_t len = reply_bufend - bufp;
|
|
memmove(reply_buffer, bufp, len);
|
|
reply_bufend = reply_buffer + len;
|
|
} else if (reply_bufend >= reply_buffer + sizeof reply_buffer) {
|
|
WHY("DNAHELPER reply buffer overrun");
|
|
DEBUGF(dnahelper, "Discarding %s", alloca_toprint(-1, reply_buffer, sizeof reply_buffer));
|
|
reply_bufend = reply_buffer;
|
|
discarding_until_nl = 1;
|
|
}
|
|
} else if(nread==0 || nread==-1){
|
|
close(dna_helper_stdout);
|
|
dna_helper_stdout = -1;
|
|
unwatch(&sched_replies);
|
|
sched_replies.poll.fd = -1;
|
|
}
|
|
}
|
|
if (sched_replies.poll.revents & (POLLHUP | POLLERR | POLLNVAL)) {
|
|
DEBUGF(dnahelper, "DNAHELPER closing stdout fd=%d", dna_helper_stdout);
|
|
close(dna_helper_stdout);
|
|
dna_helper_stdout = -1;
|
|
unwatch(&sched_replies);
|
|
sched_replies.poll.fd = -1;
|
|
dna_helper_kill();
|
|
}
|
|
}
|
|
|
|
static void monitor_errors(struct sched_ent *alarm)
|
|
{
|
|
DEBUGF(dnahelper, "sched_errors.poll.fd=%d .revents=%s",
|
|
sched_errors.poll.fd,
|
|
strbuf_str(strbuf_append_poll_events(strbuf_alloca(40), sched_errors.poll.revents))
|
|
);
|
|
assert(alarm == &sched_errors);
|
|
if (sched_errors.poll.revents & POLLIN) {
|
|
char buffer[1024];
|
|
ssize_t nread = read_nonblock(sched_errors.poll.fd, buffer, sizeof buffer);
|
|
if (nread > 0)
|
|
WHYF("DNAHELPER stderr %s", alloca_toprint(-1, buffer, nread));
|
|
if (nread==0 || nread==-1){
|
|
close(dna_helper_stderr);
|
|
dna_helper_stderr = -1;
|
|
unwatch(&sched_errors);
|
|
sched_errors.poll.fd = -1;
|
|
}
|
|
}
|
|
if (sched_errors.poll.revents & (POLLHUP | POLLERR | POLLNVAL)) {
|
|
DEBUGF(dnahelper, "DNAHELPER closing stderr fd=%d", dna_helper_stderr);
|
|
close(dna_helper_stderr);
|
|
dna_helper_stderr = -1;
|
|
unwatch(&sched_errors);
|
|
sched_errors.poll.fd = -1;
|
|
}
|
|
}
|
|
|
|
static void harvester(struct sched_ent *alarm)
|
|
{
|
|
assert(alarm == &sched_harvester);
|
|
// While the helper process appears to still be running, keep calling this function.
|
|
// Otherwise, wait a while before re-starting the helper.
|
|
if (dna_helper_harvest(0) <= 0) {
|
|
sched_harvester.alarm = gettime_ms() + 1000;
|
|
sched_harvester.deadline = sched_harvester.alarm + 1000;
|
|
schedule(&sched_harvester);
|
|
} else {
|
|
const int delay_ms = 500;
|
|
DEBUGF(dnahelper, "DNAHELPER process died, pausing %d ms before restart", delay_ms);
|
|
dna_helper_pid = 0; // Will be set to -1 after delay
|
|
sched_restart.function = restart_delayer;
|
|
sched_restart.alarm = gettime_ms() + delay_ms;
|
|
sched_restart.deadline = sched_restart.alarm + 500;
|
|
schedule(&sched_restart);
|
|
}
|
|
}
|
|
|
|
static void restart_delayer(struct sched_ent *alarm)
|
|
{
|
|
assert(alarm == &sched_restart);
|
|
if (dna_helper_pid == 0) {
|
|
DEBUG(dnahelper, "DNAHELPER re-enable restart");
|
|
dna_helper_pid = -1;
|
|
}
|
|
}
|
|
|
|
static void reply_timeout(struct sched_ent *alarm)
|
|
{
|
|
assert(alarm == &sched_timeout);
|
|
if (awaiting_reply) {
|
|
WHY("DNAHELPER reply timeout");
|
|
dna_helper_kill();
|
|
}
|
|
}
|
|
|
|
int
|
|
dna_helper_enqueue(struct subscriber *source, mdp_port_t source_port, const char *did)
|
|
{
|
|
DEBUGF(dnahelper, "DNAHELPER request did=%s sid=%s", did, alloca_tohex_sid_t(source->sid));
|
|
if (dna_helper_pid == 0)
|
|
return 0;
|
|
// Only try to restart a DNA helper process if the previous one is well and truly gone.
|
|
if (dna_helper_pid == -1 && dna_helper_stdin == -1 && dna_helper_stdout == -1 && dna_helper_stderr == -1) {
|
|
if (dna_helper_start() == -1) {
|
|
/* Something broke, bail out */
|
|
return WHY("DNAHELPER start failed");
|
|
}
|
|
}
|
|
/* Write request to dna helper.
|
|
Request takes form: SID-of-Requestor|DID|\n
|
|
By passing the requestor's SID to the helper, we don't need to maintain
|
|
any state, as all we have to do is wait for responses from the helper,
|
|
which will include the requestor's SID.
|
|
*/
|
|
if (dna_helper_stdin == -1)
|
|
return 0;
|
|
if (request_bufptr && request_bufptr != request_buffer) {
|
|
WARNF("DNAHELPER currently sending request %s -- dropping new request", request_buffer);
|
|
return 0;
|
|
}
|
|
if (awaiting_reply) {
|
|
WARN("DNAHELPER currently awaiting reply -- dropping new request");
|
|
return 0;
|
|
}
|
|
char buffer[sizeof request_buffer];
|
|
strbuf b = request_bufptr == request_buffer ? strbuf_local_buf(buffer) : strbuf_local_buf(request_buffer);
|
|
strbuf_tohex(b, SID_STRLEN, source->sid.binary);
|
|
strbuf_putc(b, '|');
|
|
strbuf_puts(b, did);
|
|
strbuf_putc(b, '|');
|
|
strbuf_putc(b, '\n');
|
|
if (strbuf_overrun(b)) {
|
|
WHYF("DNAHELPER request buffer overrun: %s -- request not sent", strbuf_str(b));
|
|
request_bufptr = request_bufend = NULL;
|
|
} else {
|
|
if (strbuf_str(b) != request_buffer) {
|
|
if (strcmp(strbuf_str(b), request_buffer) != 0)
|
|
WARNF("DNAHELPER overwriting unsent request %s", request_buffer);
|
|
strcpy(request_buffer, strbuf_str(b));
|
|
}
|
|
request_bufptr = request_buffer;
|
|
request_bufend = request_buffer + strbuf_len(b);
|
|
request_source = source;
|
|
request_port = source_port;
|
|
buf_strncpy_nul(request_did, did);
|
|
}
|
|
if (dna_helper_started) {
|
|
sched_requests.poll.fd = dna_helper_stdin;
|
|
watch(&sched_requests);
|
|
}
|
|
return 1;
|
|
}
|