diff options
| -rw-r--r-- | CHANGES | 4 | ||||
| -rw-r--r-- | lib/hostip.c | 190 | ||||
| -rw-r--r-- | lib/hostip.h | 4 | ||||
| -rw-r--r-- | lib/url.c | 143 |
4 files changed, 203 insertions, 138 deletions
@@ -6,6 +6,10 @@ Changelog +Daniel Fandrich (29 Sep 2008) +- Moved all signal-based name resolution timeout handling into a single new + Curl_resolv_timeout function to reduce coupling. + Daniel Stenberg (29 Sep 2008) - Ian Lynagh provided a patch that now makes CURLOPT_RANGE work fine for SFTP downloads! diff --git a/lib/hostip.c b/lib/hostip.c index 722c4b525..69f3c997f 100644 --- a/lib/hostip.c +++ b/lib/hostip.c @@ -55,6 +55,9 @@ #ifdef HAVE_SETJMP_H #include <setjmp.h> #endif +#ifdef HAVE_SIGNAL_H +#include <signal.h> +#endif #ifdef HAVE_PROCESS_H #include <process.h> @@ -76,6 +79,12 @@ /* The last #include file should be: */ #include "memdebug.h" +#if defined(HAVE_ALARM) && defined(SIGALRM) && defined(HAVE_SIGSETJMP) \ + && !defined(USE_ARES) +/* alarm-based timeouts can only be used with all the dependencies satisfied */ +#define USE_ALARM_TIMEOUT +#endif + /* * hostip.c explained * ================== @@ -388,19 +397,8 @@ int Curl_resolv(struct connectdata *conn, struct SessionHandle *data = conn->data; CURLcode result; int rc = CURLRESOLV_ERROR; /* default to failure */ - *entry = NULL; -#ifdef HAVE_SIGSETJMP - /* this allows us to time-out from the name resolver, as the timeout - will generate a signal and we will siglongjmp() from that here */ - if(!data->set.no_signal) { - if(sigsetjmp(curl_jmpenv, 1)) { - /* this is coming from a siglongjmp() */ - failf(data, "name lookup timed out"); - return rc; - } - } -#endif + *entry = NULL; /* Create an entry id, based upon the hostname and port */ entry_id = create_hostcache_id(hostname, port); @@ -484,6 +482,174 @@ int Curl_resolv(struct connectdata *conn, return rc; } +#ifdef USE_ALARM_TIMEOUT +/* + * This signal handler jumps back into the main libcurl code and continues + * execution. This effectively causes the remainder of the application to run + * within a signal handler which is nonportable and could lead to problems. + */ +static +RETSIGTYPE alarmfunc(int sig) +{ + /* this is for "-ansi -Wall -pedantic" to stop complaining! (rabe) */ + (void)sig; + siglongjmp(curl_jmpenv, 1); + return; +} +#endif /* USE_ALARM_TIMEOUT */ + +/* + * Curl_resolv_timeout() is the same as Curl_resolv() but specifies a + * timeout. This function might return immediately if we're using asynch + * resolves. See the return codes. + * + * The cache entry we return will get its 'inuse' counter increased when this + * function is used. You MUST call Curl_resolv_unlock() later (when you're + * done using this struct) to decrease the counter again. + * + * If built with a synchronous resolver and use of signals is not + * disabled by the application, then a nonzero timeout will cause a + * timeout after the specified number of milliseconds. Otherwise, timeout + * is ignored. + * + * Return codes: + * + * CURLRESOLV_TIMEDOUT(-2) = warning, time too short or previous alarm expired + * CURLRESOLV_ERROR (-1) = error, no pointer + * CURLRESOLV_RESOLVED (0) = OK, pointer provided + * CURLRESOLV_PENDING (1) = waiting for response, no pointer + */ + +int Curl_resolv_timeout(struct connectdata *conn, + const char *hostname, + int port, + struct Curl_dns_entry **entry, + long timeout) +{ +#ifdef USE_ALARM_TIMEOUT +#ifdef HAVE_SIGACTION + struct sigaction keep_sigact; /* store the old struct here */ + bool keep_copysig=FALSE; /* did copy it? */ + struct sigaction sigact; +#else +#ifdef HAVE_SIGNAL + void (*keep_sigact)(int); /* store the old handler here */ +#endif /* HAVE_SIGNAL */ +#endif /* HAVE_SIGACTION */ + + unsigned int prev_alarm=0; +#endif /* USE_ALARM_TIMEOUT */ + + struct SessionHandle *data = conn->data; + int rc = CURLRESOLV_ERROR; /* error by default */ + + *entry = NULL; + +#ifdef USE_ALARM_TIMEOUT + if (data->set.no_signal) + /* Ignore the timeout when signals are disabled */ + timeout = 0; + + if(timeout && timeout < 1000) + /* The alarm() function only provides integer second resolution, so if + we want to wait less than one second we must bail out already now. */ + return CURLRESOLV_TIMEDOUT; + + if (timeout > 0) { + /* This allows us to time-out from the name resolver, as the timeout + will generate a signal and we will siglongjmp() from that here. + This technique has problems (see alarmfunc). */ + if(sigsetjmp(curl_jmpenv, 1)) { + /* this is coming from a siglongjmp() after an alarm signal */ + failf(data, "name lookup timed out"); + return rc; + } + + /************************************************************* + * Set signal handler to catch SIGALRM + * Store the old value to be able to set it back later! + *************************************************************/ +#ifdef HAVE_SIGACTION + sigaction(SIGALRM, NULL, &sigact); + keep_sigact = sigact; + keep_copysig = TRUE; /* yes, we have a copy */ + sigact.sa_handler = alarmfunc; +#ifdef SA_RESTART + /* HPUX doesn't have SA_RESTART but defaults to that behaviour! */ + sigact.sa_flags &= ~SA_RESTART; +#endif + /* now set the new struct */ + sigaction(SIGALRM, &sigact, NULL); +#else /* HAVE_SIGACTION */ + /* no sigaction(), revert to the much lamer signal() */ +#ifdef HAVE_SIGNAL + keep_sigact = signal(SIGALRM, alarmfunc); +#endif +#endif /* HAVE_SIGACTION */ + + /* alarm() makes a signal get sent when the timeout fires off, and that + will abort system calls */ + prev_alarm = alarm((unsigned int) (timeout ? timeout/1000L : timeout)); + } + +#else +#ifndef CURLRES_ASYNCH + if(timeout) + infof(data, "timeout on name lookup is not supported\n"); +#endif +#endif /* USE_ALARM_TIMEOUT */ + + /* Perform the actual name resolution. This might be interrupted by an + * alarm if it takes too long. + */ + rc = Curl_resolv(conn, hostname, port, entry); + +#ifdef USE_ALARM_TIMEOUT + if (timeout > 0) { + +#ifdef HAVE_SIGACTION + if(keep_copysig) { + /* we got a struct as it looked before, now put that one back nice + and clean */ + sigaction(SIGALRM, &keep_sigact, NULL); /* put it back */ + } +#else +#ifdef HAVE_SIGNAL + /* restore the previous SIGALRM handler */ + signal(SIGALRM, keep_sigact); +#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); + + /* the alarm period is counted in even number of seconds */ + unsigned long 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); + rc = CURLRESOLV_TIMEDOUT; + failf(data, "Previous alarm fired off!"); + } + else + alarm((unsigned int)alarm_set); + } + else + alarm(0); /* just shut it off */ + } +#endif /* USE_ALARM_TIMEOUT */ + + return rc; +} + /* * Curl_resolv_unlock() unlocks the given cached DNS entry. When this has been * made, the struct may be destroyed due to pruning. It is important that only diff --git a/lib/hostip.h b/lib/hostip.h index c6172be0f..3864dd90b 100644 --- a/lib/hostip.h +++ b/lib/hostip.h @@ -158,11 +158,15 @@ struct Curl_dns_entry { * use, or we'll leak memory! */ /* return codes */ +#define CURLRESOLV_TIMEDOUT -2 #define CURLRESOLV_ERROR -1 #define CURLRESOLV_RESOLVED 0 #define CURLRESOLV_PENDING 1 int Curl_resolv(struct connectdata *conn, const char *hostname, int port, struct Curl_dns_entry **dnsentry); +int Curl_resolv_timeout(struct connectdata *conn, const char *hostname, + int port, struct Curl_dns_entry **dnsentry, + long timeout); /* * Curl_ipvalid() checks what CURL_IPRESOLVE_* requirements that might've @@ -60,9 +60,6 @@ #ifdef HAVE_SYS_IOCTL_H #include <sys/ioctl.h> #endif -#ifdef HAVE_SIGNAL_H -#include <signal.h> -#endif #ifdef HAVE_SYS_PARAM_H #include <sys/param.h> @@ -73,10 +70,6 @@ #include <inet.h> #endif -#ifdef HAVE_SETJMP_H -#include <setjmp.h> -#endif - #ifndef HAVE_SOCKET #error "We can't compile without socket() support!" #endif @@ -169,27 +162,6 @@ static void flush_cookies(struct SessionHandle *data, int cleanup); #define verboseconnect(x) do { } while (0) #endif -#ifndef WIN32 -/* not for WIN32 builds */ - -#if defined(HAVE_ALARM) && defined(SIGALRM) && !defined(USE_ARES) -/* - * This signal handler jumps back into the main libcurl code and continues - * execution. This effectively causes the remainder of the application to run - * within a signal handler which is nonportable and could lead to problems. - */ -static -RETSIGTYPE alarmfunc(int sig) -{ - /* this is for "-ansi -Wall -pedantic" to stop complaining! (rabe) */ - (void)sig; -#ifdef HAVE_SIGSETJMP - siglongjmp(curl_jmpenv, 1); -#endif - return; -} -#endif /* HAVE_ALARM && SIGALRM && !USE_ARES */ -#endif /* WIN32 */ /* * Protocol table. @@ -3788,34 +3760,19 @@ static CURLcode resolve_server(struct SessionHandle *data, bool *async) { CURLcode result=CURLE_OK; - -#if defined(HAVE_ALARM) && defined(SIGALRM) && !defined(USE_ARES) -#ifdef HAVE_SIGACTION - struct sigaction keep_sigact; /* store the old struct here */ - bool keep_copysig=FALSE; /* did copy it? */ -#else -#ifdef HAVE_SIGNAL - void (*keep_sigact)(int); /* store the old handler here */ -#endif /* HAVE_SIGNAL */ -#endif /* HAVE_SIGACTION */ - - unsigned int prev_alarm=0; + long shortest = 0; /* default to no timeout */ /************************************************************* - * Set timeout if that is being used, and we're not using an asynchronous - * name resolve. + * Set timeout if that is being used *************************************************************/ - if((data->set.timeout || data->set.connecttimeout) && !data->set.no_signal) { -#ifdef HAVE_SIGACTION - struct sigaction sigact; -#endif /* HAVE_SIGACTION */ + if(data->set.timeout || data->set.connecttimeout) { /* We set the timeout on the name resolving phase first, separately from * the download/upload part to allow a maximum time on everything. This is * a signal-based timeout, why it won't work and shouldn't be used in * multi-threaded environments. */ - long shortest = data->set.timeout; /* default to this timeout value */ + shortest = data->set.timeout; /* default to this timeout value */ if(shortest && data->set.connecttimeout && (data->set.connecttimeout < shortest)) /* if both are set, pick the shortest */ @@ -3823,42 +3780,10 @@ static CURLcode resolve_server(struct SessionHandle *data, else if(!shortest) /* if timeout is not set, use the connect timeout */ shortest = data->set.connecttimeout; - - if(shortest < 1000) - /* the alarm() function only provide integer second resolution, so if - we want to wait less than one second we must bail out already now. */ - return CURLE_OPERATION_TIMEDOUT; - - /************************************************************* - * Set signal handler to catch SIGALRM - * Store the old value to be able to set it back later! - *************************************************************/ -#ifdef HAVE_SIGACTION - sigaction(SIGALRM, NULL, &sigact); - keep_sigact = sigact; - keep_copysig = TRUE; /* yes, we have a copy */ - sigact.sa_handler = alarmfunc; -#ifdef SA_RESTART - /* HPUX doesn't have SA_RESTART but defaults to that behaviour! */ - sigact.sa_flags &= ~SA_RESTART; -#endif - /* now set the new struct */ - sigaction(SIGALRM, &sigact, NULL); -#else /* HAVE_SIGACTION */ - /* no sigaction(), revert to the much lamer signal() */ -#ifdef HAVE_SIGNAL - keep_sigact = signal(SIGALRM, alarmfunc); -#endif -#endif /* HAVE_SIGACTION */ - - /* alarm() makes a signal get sent when the timeout fires off, and that - will abort system calls */ - prev_alarm = alarm((unsigned int) (shortest ? shortest/1000L : shortest)); - /* We can expect the conn->created time to be "now", as that was just - recently set in the beginning of this function and nothing slow - has been done since then until now. */ + /* We can expect the conn->created time to be "now", as that was just + recently set in the beginning of this function and nothing slow + has been done since then until now. */ } -#endif /* HAVE_ALARM && SIGALRM && !USE_ARES */ /************************************************************* * Resolve the name of the server or proxy @@ -3885,10 +3810,14 @@ static CURLcode resolve_server(struct SessionHandle *data, conn->port = conn->remote_port; /* it is the same port */ /* Resolve target host right on */ - rc = Curl_resolv(conn, conn->host.name, (int)conn->port, &hostaddr); + rc = Curl_resolv_timeout(conn, conn->host.name, (int)conn->port, + &hostaddr, shortest); if(rc == CURLRESOLV_PENDING) *async = TRUE; + else if (rc == CURLRESOLV_TIMEDOUT) + result = CURLE_OPERATION_TIMEDOUT; + else if(!hostaddr) { failf(data, "Couldn't resolve host '%s'", conn->host.dispname); result = CURLE_COULDNT_RESOLVE_HOST; @@ -3902,11 +3831,15 @@ static CURLcode resolve_server(struct SessionHandle *data, fix_hostname(data, conn, &conn->proxy); /* resolve proxy */ - rc = Curl_resolv(conn, conn->proxy.name, (int)conn->port, &hostaddr); + rc = Curl_resolv_timeout(conn, conn->proxy.name, (int)conn->port, + &hostaddr, shortest); if(rc == CURLRESOLV_PENDING) *async = TRUE; + else if (rc == CURLRESOLV_TIMEDOUT) + result = CURLE_OPERATION_TIMEDOUT; + else if(!hostaddr) { failf(data, "Couldn't resolve proxy '%s'", conn->proxy.dispname); result = CURLE_COULDNT_RESOLVE_PROXY; @@ -3916,48 +3849,6 @@ static CURLcode resolve_server(struct SessionHandle *data, *addr = hostaddr; } -#if defined(HAVE_ALARM) && defined(SIGALRM) && !defined(USE_ARES) - if((data->set.timeout || data->set.connecttimeout) && !data->set.no_signal) { -#ifdef HAVE_SIGACTION - if(keep_copysig) { - /* we got a struct as it looked before, now put that one back nice - and clean */ - sigaction(SIGALRM, &keep_sigact, NULL); /* put it back */ - } -#else -#ifdef HAVE_SIGNAL - /* restore the previous SIGALRM handler */ - signal(SIGALRM, keep_sigact); -#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; } |