mirror of
https://github.com/moparisthebest/curl
synced 2024-12-21 23:58:49 -05:00
Moved all signal-based name resolution timeout handling into a single new
Curl_resolv_timeout function to reduce coupling.
This commit is contained in:
Dan Fandrich
parent
9f8c40ed78
commit
4adcf7e9ed
4
CHANGES
4
CHANGES
@ -6,6 +6,10 @@
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Changelog
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Daniel Fandrich (29 Sep 2008)
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- Moved all signal-based name resolution timeout handling into a single new
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Curl_resolv_timeout function to reduce coupling.
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Daniel Stenberg (29 Sep 2008)
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- Ian Lynagh provided a patch that now makes CURLOPT_RANGE work fine for SFTP
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downloads!
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190
lib/hostip.c
190
lib/hostip.c
@ -55,6 +55,9 @@
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#ifdef HAVE_SETJMP_H
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#include <setjmp.h>
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#endif
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#ifdef HAVE_SIGNAL_H
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#include <signal.h>
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#endif
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#ifdef HAVE_PROCESS_H
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#include <process.h>
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@ -76,6 +79,12 @@
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/* The last #include file should be: */
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#include "memdebug.h"
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#if defined(HAVE_ALARM) && defined(SIGALRM) && defined(HAVE_SIGSETJMP) \
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&& !defined(USE_ARES)
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/* alarm-based timeouts can only be used with all the dependencies satisfied */
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#define USE_ALARM_TIMEOUT
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#endif
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/*
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* hostip.c explained
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* ==================
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@ -388,19 +397,8 @@ int Curl_resolv(struct connectdata *conn,
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struct SessionHandle *data = conn->data;
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CURLcode result;
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int rc = CURLRESOLV_ERROR; /* default to failure */
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*entry = NULL;
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#ifdef HAVE_SIGSETJMP
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/* this allows us to time-out from the name resolver, as the timeout
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will generate a signal and we will siglongjmp() from that here */
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if(!data->set.no_signal) {
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if(sigsetjmp(curl_jmpenv, 1)) {
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/* this is coming from a siglongjmp() */
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failf(data, "name lookup timed out");
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return rc;
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}
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}
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#endif
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*entry = NULL;
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/* Create an entry id, based upon the hostname and port */
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entry_id = create_hostcache_id(hostname, port);
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@ -484,6 +482,174 @@ int Curl_resolv(struct connectdata *conn,
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return rc;
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}
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#ifdef USE_ALARM_TIMEOUT
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/*
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* This signal handler jumps back into the main libcurl code and continues
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* execution. This effectively causes the remainder of the application to run
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* within a signal handler which is nonportable and could lead to problems.
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*/
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static
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RETSIGTYPE alarmfunc(int sig)
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{
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/* this is for "-ansi -Wall -pedantic" to stop complaining! (rabe) */
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(void)sig;
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siglongjmp(curl_jmpenv, 1);
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return;
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}
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#endif /* USE_ALARM_TIMEOUT */
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/*
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* Curl_resolv_timeout() is the same as Curl_resolv() but specifies a
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* timeout. This function might return immediately if we're using asynch
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* resolves. See the return codes.
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*
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* The cache entry we return will get its 'inuse' counter increased when this
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* function is used. You MUST call Curl_resolv_unlock() later (when you're
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* done using this struct) to decrease the counter again.
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*
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* If built with a synchronous resolver and use of signals is not
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* disabled by the application, then a nonzero timeout will cause a
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* timeout after the specified number of milliseconds. Otherwise, timeout
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* is ignored.
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*
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* Return codes:
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*
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* CURLRESOLV_TIMEDOUT(-2) = warning, time too short or previous alarm expired
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* CURLRESOLV_ERROR (-1) = error, no pointer
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* CURLRESOLV_RESOLVED (0) = OK, pointer provided
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* CURLRESOLV_PENDING (1) = waiting for response, no pointer
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*/
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int Curl_resolv_timeout(struct connectdata *conn,
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const char *hostname,
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int port,
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struct Curl_dns_entry **entry,
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long timeout)
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{
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#ifdef USE_ALARM_TIMEOUT
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#ifdef HAVE_SIGACTION
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struct sigaction keep_sigact; /* store the old struct here */
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bool keep_copysig=FALSE; /* did copy it? */
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struct sigaction sigact;
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#else
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#ifdef HAVE_SIGNAL
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void (*keep_sigact)(int); /* store the old handler here */
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#endif /* HAVE_SIGNAL */
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#endif /* HAVE_SIGACTION */
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unsigned int prev_alarm=0;
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#endif /* USE_ALARM_TIMEOUT */
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struct SessionHandle *data = conn->data;
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int rc = CURLRESOLV_ERROR; /* error by default */
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*entry = NULL;
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#ifdef USE_ALARM_TIMEOUT
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if (data->set.no_signal)
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/* Ignore the timeout when signals are disabled */
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timeout = 0;
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if(timeout && timeout < 1000)
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/* The alarm() function only provides integer second resolution, so if
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we want to wait less than one second we must bail out already now. */
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return CURLRESOLV_TIMEDOUT;
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if (timeout > 0) {
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/* This allows us to time-out from the name resolver, as the timeout
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will generate a signal and we will siglongjmp() from that here.
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This technique has problems (see alarmfunc). */
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if(sigsetjmp(curl_jmpenv, 1)) {
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/* this is coming from a siglongjmp() after an alarm signal */
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failf(data, "name lookup timed out");
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return rc;
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}
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/*************************************************************
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* Set signal handler to catch SIGALRM
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* Store the old value to be able to set it back later!
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*************************************************************/
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#ifdef HAVE_SIGACTION
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sigaction(SIGALRM, NULL, &sigact);
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keep_sigact = sigact;
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keep_copysig = TRUE; /* yes, we have a copy */
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sigact.sa_handler = alarmfunc;
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#ifdef SA_RESTART
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/* HPUX doesn't have SA_RESTART but defaults to that behaviour! */
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sigact.sa_flags &= ~SA_RESTART;
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#endif
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/* now set the new struct */
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sigaction(SIGALRM, &sigact, NULL);
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#else /* HAVE_SIGACTION */
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/* no sigaction(), revert to the much lamer signal() */
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#ifdef HAVE_SIGNAL
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keep_sigact = signal(SIGALRM, alarmfunc);
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#endif
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#endif /* HAVE_SIGACTION */
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/* alarm() makes a signal get sent when the timeout fires off, and that
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will abort system calls */
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prev_alarm = alarm((unsigned int) (timeout ? timeout/1000L : timeout));
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}
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#else
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#ifndef CURLRES_ASYNCH
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if(timeout)
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infof(data, "timeout on name lookup is not supported\n");
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#endif
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#endif /* USE_ALARM_TIMEOUT */
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/* Perform the actual name resolution. This might be interrupted by an
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* alarm if it takes too long.
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*/
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rc = Curl_resolv(conn, hostname, port, entry);
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#ifdef USE_ALARM_TIMEOUT
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if (timeout > 0) {
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#ifdef HAVE_SIGACTION
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if(keep_copysig) {
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/* we got a struct as it looked before, now put that one back nice
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and clean */
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sigaction(SIGALRM, &keep_sigact, NULL); /* put it back */
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}
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#else
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#ifdef HAVE_SIGNAL
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/* restore the previous SIGALRM handler */
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signal(SIGALRM, keep_sigact);
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#endif
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#endif /* HAVE_SIGACTION */
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/* switch back the alarm() to either zero or to what it was before minus
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the time we spent until now! */
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if(prev_alarm) {
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/* there was an alarm() set before us, now put it back */
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unsigned long elapsed_ms = Curl_tvdiff(Curl_tvnow(), conn->created);
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/* the alarm period is counted in even number of seconds */
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unsigned long alarm_set = prev_alarm - elapsed_ms/1000;
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if(!alarm_set ||
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((alarm_set >= 0x80000000) && (prev_alarm < 0x80000000)) ) {
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/* if the alarm time-left reached zero or turned "negative" (counted
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with unsigned values), we should fire off a SIGALRM here, but we
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won't, and zero would be to switch it off so we never set it to
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less than 1! */
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alarm(1);
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rc = CURLRESOLV_TIMEDOUT;
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failf(data, "Previous alarm fired off!");
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}
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else
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alarm((unsigned int)alarm_set);
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}
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else
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alarm(0); /* just shut it off */
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}
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#endif /* USE_ALARM_TIMEOUT */
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return rc;
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}
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/*
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* Curl_resolv_unlock() unlocks the given cached DNS entry. When this has been
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* made, the struct may be destroyed due to pruning. It is important that only
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@ -158,11 +158,15 @@ struct Curl_dns_entry {
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* use, or we'll leak memory!
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*/
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/* return codes */
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#define CURLRESOLV_TIMEDOUT -2
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#define CURLRESOLV_ERROR -1
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#define CURLRESOLV_RESOLVED 0
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#define CURLRESOLV_PENDING 1
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int Curl_resolv(struct connectdata *conn, const char *hostname,
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int port, struct Curl_dns_entry **dnsentry);
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int Curl_resolv_timeout(struct connectdata *conn, const char *hostname,
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int port, struct Curl_dns_entry **dnsentry,
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long timeout);
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/*
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* Curl_ipvalid() checks what CURL_IPRESOLVE_* requirements that might've
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137
lib/url.c
137
lib/url.c
@ -60,9 +60,6 @@
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#ifdef HAVE_SYS_IOCTL_H
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#include <sys/ioctl.h>
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#endif
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#ifdef HAVE_SIGNAL_H
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#include <signal.h>
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#endif
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#ifdef HAVE_SYS_PARAM_H
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#include <sys/param.h>
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@ -73,10 +70,6 @@
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#include <inet.h>
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#endif
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#ifdef HAVE_SETJMP_H
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#include <setjmp.h>
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#endif
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#ifndef HAVE_SOCKET
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#error "We can't compile without socket() support!"
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#endif
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@ -169,27 +162,6 @@ static void flush_cookies(struct SessionHandle *data, int cleanup);
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#define verboseconnect(x) do { } while (0)
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#endif
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#ifndef WIN32
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/* not for WIN32 builds */
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#if defined(HAVE_ALARM) && defined(SIGALRM) && !defined(USE_ARES)
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/*
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* This signal handler jumps back into the main libcurl code and continues
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* execution. This effectively causes the remainder of the application to run
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* within a signal handler which is nonportable and could lead to problems.
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*/
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static
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RETSIGTYPE alarmfunc(int sig)
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{
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/* this is for "-ansi -Wall -pedantic" to stop complaining! (rabe) */
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(void)sig;
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#ifdef HAVE_SIGSETJMP
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siglongjmp(curl_jmpenv, 1);
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#endif
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return;
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}
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#endif /* HAVE_ALARM && SIGALRM && !USE_ARES */
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#endif /* WIN32 */
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/*
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* Protocol table.
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@ -3788,34 +3760,19 @@ static CURLcode resolve_server(struct SessionHandle *data,
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bool *async)
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{
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CURLcode result=CURLE_OK;
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#if defined(HAVE_ALARM) && defined(SIGALRM) && !defined(USE_ARES)
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#ifdef HAVE_SIGACTION
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struct sigaction keep_sigact; /* store the old struct here */
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bool keep_copysig=FALSE; /* did copy it? */
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#else
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#ifdef HAVE_SIGNAL
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void (*keep_sigact)(int); /* store the old handler here */
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#endif /* HAVE_SIGNAL */
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#endif /* HAVE_SIGACTION */
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unsigned int prev_alarm=0;
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long shortest = 0; /* default to no timeout */
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/*************************************************************
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* Set timeout if that is being used, and we're not using an asynchronous
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* name resolve.
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* Set timeout if that is being used
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*************************************************************/
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if((data->set.timeout || data->set.connecttimeout) && !data->set.no_signal) {
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#ifdef HAVE_SIGACTION
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struct sigaction sigact;
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#endif /* HAVE_SIGACTION */
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if(data->set.timeout || data->set.connecttimeout) {
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/* We set the timeout on the name resolving phase first, separately from
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* the download/upload part to allow a maximum time on everything. This is
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* a signal-based timeout, why it won't work and shouldn't be used in
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* multi-threaded environments. */
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long shortest = data->set.timeout; /* default to this timeout value */
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shortest = data->set.timeout; /* default to this timeout value */
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if(shortest && data->set.connecttimeout &&
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(data->set.connecttimeout < shortest))
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/* if both are set, pick the shortest */
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@ -3823,42 +3780,10 @@ static CURLcode resolve_server(struct SessionHandle *data,
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else if(!shortest)
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/* if timeout is not set, use the connect timeout */
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shortest = data->set.connecttimeout;
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if(shortest < 1000)
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/* the alarm() function only provide integer second resolution, so if
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we want to wait less than one second we must bail out already now. */
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return CURLE_OPERATION_TIMEDOUT;
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/*************************************************************
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* Set signal handler to catch SIGALRM
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* Store the old value to be able to set it back later!
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*************************************************************/
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#ifdef HAVE_SIGACTION
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sigaction(SIGALRM, NULL, &sigact);
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keep_sigact = sigact;
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keep_copysig = TRUE; /* yes, we have a copy */
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sigact.sa_handler = alarmfunc;
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#ifdef SA_RESTART
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/* HPUX doesn't have SA_RESTART but defaults to that behaviour! */
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sigact.sa_flags &= ~SA_RESTART;
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#endif
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/* now set the new struct */
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sigaction(SIGALRM, &sigact, NULL);
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#else /* HAVE_SIGACTION */
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/* no sigaction(), revert to the much lamer signal() */
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#ifdef HAVE_SIGNAL
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keep_sigact = signal(SIGALRM, alarmfunc);
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#endif
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#endif /* HAVE_SIGACTION */
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/* alarm() makes a signal get sent when the timeout fires off, and that
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will abort system calls */
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prev_alarm = alarm((unsigned int) (shortest ? shortest/1000L : shortest));
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/* We can expect the conn->created time to be "now", as that was just
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recently set in the beginning of this function and nothing slow
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has been done since then until now. */
|
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}
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#endif /* HAVE_ALARM && SIGALRM && !USE_ARES */
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/*************************************************************
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* Resolve the name of the server or proxy
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@ -3885,10 +3810,14 @@ static CURLcode resolve_server(struct SessionHandle *data,
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conn->port = conn->remote_port; /* it is the same port */
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/* Resolve target host right on */
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rc = Curl_resolv(conn, conn->host.name, (int)conn->port, &hostaddr);
|
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rc = Curl_resolv_timeout(conn, conn->host.name, (int)conn->port,
|
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&hostaddr, shortest);
|
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if(rc == CURLRESOLV_PENDING)
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*async = TRUE;
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else if (rc == CURLRESOLV_TIMEDOUT)
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result = CURLE_OPERATION_TIMEDOUT;
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else if(!hostaddr) {
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failf(data, "Couldn't resolve host '%s'", conn->host.dispname);
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result = CURLE_COULDNT_RESOLVE_HOST;
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@ -3902,11 +3831,15 @@ static CURLcode resolve_server(struct SessionHandle *data,
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fix_hostname(data, conn, &conn->proxy);
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/* resolve proxy */
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rc = Curl_resolv(conn, conn->proxy.name, (int)conn->port, &hostaddr);
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rc = Curl_resolv_timeout(conn, conn->proxy.name, (int)conn->port,
|
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&hostaddr, shortest);
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if(rc == CURLRESOLV_PENDING)
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*async = TRUE;
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else if (rc == CURLRESOLV_TIMEDOUT)
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result = CURLE_OPERATION_TIMEDOUT;
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||||
|
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else if(!hostaddr) {
|
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failf(data, "Couldn't resolve proxy '%s'", conn->proxy.dispname);
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result = CURLE_COULDNT_RESOLVE_PROXY;
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@ -3916,48 +3849,6 @@ static CURLcode resolve_server(struct SessionHandle *data,
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*addr = hostaddr;
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}
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#if defined(HAVE_ALARM) && defined(SIGALRM) && !defined(USE_ARES)
|
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if((data->set.timeout || data->set.connecttimeout) && !data->set.no_signal) {
|
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#ifdef HAVE_SIGACTION
|
||||
if(keep_copysig) {
|
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/* we got a struct as it looked before, now put that one back nice
|
||||
and clean */
|
||||
sigaction(SIGALRM, &keep_sigact, NULL); /* put it back */
|
||||
}
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#else
|
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#ifdef HAVE_SIGNAL
|
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/* restore the previous SIGALRM handler */
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signal(SIGALRM, keep_sigact);
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||||
#endif
|
||||
#endif /* HAVE_SIGACTION */
|
||||
|
||||
/* switch back the alarm() to either zero or to what it was before minus
|
||||
the time we spent until now! */
|
||||
if(prev_alarm) {
|
||||
/* there was an alarm() set before us, now put it back */
|
||||
unsigned long elapsed_ms = Curl_tvdiff(Curl_tvnow(), conn->created);
|
||||
unsigned long alarm_set;
|
||||
|
||||
/* the alarm period is counted in even number of seconds */
|
||||
alarm_set = prev_alarm - elapsed_ms/1000;
|
||||
|
||||
if(!alarm_set ||
|
||||
((alarm_set >= 0x80000000) && (prev_alarm < 0x80000000)) ) {
|
||||
/* if the alarm time-left reached zero or turned "negative" (counted
|
||||
with unsigned values), we should fire off a SIGALRM here, but we
|
||||
won't, and zero would be to switch it off so we never set it to
|
||||
less than 1! */
|
||||
alarm(1);
|
||||
result = CURLE_OPERATION_TIMEDOUT;
|
||||
failf(data, "Previous alarm fired off!");
|
||||
}
|
||||
else
|
||||
alarm((unsigned int)alarm_set);
|
||||
}
|
||||
else
|
||||
alarm(0); /* just shut it off */
|
||||
}
|
||||
#endif /* HAVE_ALARM && SIGALRM && !USE_ARES */
|
||||
return result;
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user