diff options
Diffstat (limited to 'Utilities/cmcurl/lib/hostip.c')
| -rw-r--r-- | Utilities/cmcurl/lib/hostip.c | 1047 |
1 files changed, 1047 insertions, 0 deletions
diff --git a/Utilities/cmcurl/lib/hostip.c b/Utilities/cmcurl/lib/hostip.c new file mode 100644 index 0000000..c2f9def --- /dev/null +++ b/Utilities/cmcurl/lib/hostip.c @@ -0,0 +1,1047 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al. + * + * This software is licensed as described in the file COPYING, which + * you should have received as part of this distribution. The terms + * are also available at https://curl.haxx.se/docs/copyright.html. + * + * You may opt to use, copy, modify, merge, publish, distribute and/or sell + * copies of the Software, and permit persons to whom the Software is + * furnished to do so, under the terms of the COPYING file. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ***************************************************************************/ + +#include "curl_setup.h" + +#ifdef HAVE_NETINET_IN_H +#include <netinet/in.h> +#endif +#ifdef HAVE_NETINET_IN6_H +#include <netinet/in6.h> +#endif +#ifdef HAVE_NETDB_H +#include <netdb.h> +#endif +#ifdef HAVE_ARPA_INET_H +#include <arpa/inet.h> +#endif +#ifdef __VMS +#include <in.h> +#include <inet.h> +#endif + +#ifdef HAVE_SETJMP_H +#include <setjmp.h> +#endif +#ifdef HAVE_SIGNAL_H +#include <signal.h> +#endif + +#ifdef HAVE_PROCESS_H +#include <process.h> +#endif + +#include "urldata.h" +#include "sendf.h" +#include "hostip.h" +#include "hash.h" +#include "rand.h" +#include "share.h" +#include "strerror.h" +#include "url.h" +#include "inet_ntop.h" +#include "multiif.h" +#include "warnless.h" +/* The last 3 #include files should be in this order */ +#include "curl_printf.h" +#include "curl_memory.h" +#include "memdebug.h" + +#if defined(CURLRES_SYNCH) && \ + defined(HAVE_ALARM) && defined(SIGALRM) && defined(HAVE_SIGSETJMP) +/* alarm-based timeouts can only be used with all the dependencies satisfied */ +#define USE_ALARM_TIMEOUT +#endif + +/* + * hostip.c explained + * ================== + * + * The main COMPILE-TIME DEFINES to keep in mind when reading the host*.c + * source file are these: + * + * CURLRES_IPV6 - this host has getaddrinfo() and family, and thus we use + * that. The host may not be able to resolve IPv6, but we don't really have to + * take that into account. Hosts that aren't IPv6-enabled have CURLRES_IPV4 + * defined. + * + * CURLRES_ARES - is defined if libcurl is built to use c-ares for + * asynchronous name resolves. This can be Windows or *nix. + * + * CURLRES_THREADED - is defined if libcurl is built to run under (native) + * Windows, and then the name resolve will be done in a new thread, and the + * supported API will be the same as for ares-builds. + * + * If any of the two previous are defined, CURLRES_ASYNCH is defined too. If + * libcurl is not built to use an asynchronous resolver, CURLRES_SYNCH is + * defined. + * + * The host*.c sources files are split up like this: + * + * hostip.c - method-independent resolver functions and utility functions + * hostasyn.c - functions for asynchronous name resolves + * hostsyn.c - functions for synchronous name resolves + * hostip4.c - IPv4 specific functions + * hostip6.c - IPv6 specific functions + * + * The two asynchronous name resolver backends are implemented in: + * asyn-ares.c - functions for ares-using name resolves + * asyn-thread.c - functions for threaded name resolves + + * The hostip.h is the united header file for all this. It defines the + * CURLRES_* defines based on the config*.h and curl_setup.h defines. + */ + +/* These two symbols are for the global DNS cache */ +static struct curl_hash hostname_cache; +static int host_cache_initialized; + +static void freednsentry(void *freethis); + +/* + * Curl_global_host_cache_init() initializes and sets up a global DNS cache. + * Global DNS cache is general badness. Do not use. This will be removed in + * a future version. Use the share interface instead! + * + * Returns a struct curl_hash pointer on success, NULL on failure. + */ +struct curl_hash *Curl_global_host_cache_init(void) +{ + int rc = 0; + if(!host_cache_initialized) { + rc = Curl_hash_init(&hostname_cache, 7, Curl_hash_str, + Curl_str_key_compare, freednsentry); + if(!rc) + host_cache_initialized = 1; + } + return rc?NULL:&hostname_cache; +} + +/* + * Destroy and cleanup the global DNS cache + */ +void Curl_global_host_cache_dtor(void) +{ + if(host_cache_initialized) { + Curl_hash_destroy(&hostname_cache); + host_cache_initialized = 0; + } +} + +/* + * Return # of addresses in a Curl_addrinfo struct + */ +int Curl_num_addresses(const Curl_addrinfo *addr) +{ + int i = 0; + while(addr) { + addr = addr->ai_next; + i++; + } + return i; +} + +/* + * Curl_printable_address() returns a printable version of the 1st address + * given in the 'ai' argument. The result will be stored in the buf that is + * bufsize bytes big. + * + * If the conversion fails, it returns NULL. + */ +const char * +Curl_printable_address(const Curl_addrinfo *ai, char *buf, size_t bufsize) +{ + const struct sockaddr_in *sa4; + const struct in_addr *ipaddr4; +#ifdef ENABLE_IPV6 + const struct sockaddr_in6 *sa6; + const struct in6_addr *ipaddr6; +#endif + + switch(ai->ai_family) { + case AF_INET: + sa4 = (const void *)ai->ai_addr; + ipaddr4 = &sa4->sin_addr; + return Curl_inet_ntop(ai->ai_family, (const void *)ipaddr4, buf, + bufsize); +#ifdef ENABLE_IPV6 + case AF_INET6: + sa6 = (const void *)ai->ai_addr; + ipaddr6 = &sa6->sin6_addr; + return Curl_inet_ntop(ai->ai_family, (const void *)ipaddr6, buf, + bufsize); +#endif + default: + break; + } + return NULL; +} + +/* + * Return a hostcache id string for the provided host + port, to be used by + * the DNS caching. + */ +static char * +create_hostcache_id(const char *name, int port) +{ + /* create and return the new allocated entry */ + char *id = aprintf("%s:%d", name, port); + char *ptr = id; + if(ptr) { + /* lower case the name part */ + while(*ptr && (*ptr != ':')) { + *ptr = (char)TOLOWER(*ptr); + ptr++; + } + } + return id; +} + +struct hostcache_prune_data { + long cache_timeout; + time_t now; +}; + +/* + * This function is set as a callback to be called for every entry in the DNS + * cache when we want to prune old unused entries. + * + * Returning non-zero means remove the entry, return 0 to keep it in the + * cache. + */ +static int +hostcache_timestamp_remove(void *datap, void *hc) +{ + struct hostcache_prune_data *data = + (struct hostcache_prune_data *) datap; + struct Curl_dns_entry *c = (struct Curl_dns_entry *) hc; + + return (0 != c->timestamp) + && (data->now - c->timestamp >= data->cache_timeout); +} + +/* + * Prune the DNS cache. This assumes that a lock has already been taken. + */ +static void +hostcache_prune(struct curl_hash *hostcache, long cache_timeout, time_t now) +{ + struct hostcache_prune_data user; + + user.cache_timeout = cache_timeout; + user.now = now; + + Curl_hash_clean_with_criterium(hostcache, + (void *) &user, + hostcache_timestamp_remove); +} + +/* + * Library-wide function for pruning the DNS cache. This function takes and + * returns the appropriate locks. + */ +void Curl_hostcache_prune(struct Curl_easy *data) +{ + time_t now; + + if((data->set.dns_cache_timeout == -1) || !data->dns.hostcache) + /* cache forever means never prune, and NULL hostcache means + we can't do it */ + return; + + if(data->share) + Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE); + + time(&now); + + /* Remove outdated and unused entries from the hostcache */ + hostcache_prune(data->dns.hostcache, + data->set.dns_cache_timeout, + now); + + if(data->share) + Curl_share_unlock(data, CURL_LOCK_DATA_DNS); +} + +#ifdef HAVE_SIGSETJMP +/* Beware this is a global and unique instance. This is used to store the + return address that we can jump back to from inside a signal handler. This + is not thread-safe stuff. */ +sigjmp_buf curl_jmpenv; +#endif + +/* lookup address, returns entry if found and not stale */ +static struct Curl_dns_entry * +fetch_addr(struct connectdata *conn, + const char *hostname, + int port) +{ + char *entry_id = NULL; + struct Curl_dns_entry *dns = NULL; + size_t entry_len; + struct Curl_easy *data = conn->data; + + /* Create an entry id, based upon the hostname and port */ + entry_id = create_hostcache_id(hostname, port); + /* If we can't create the entry id, fail */ + if(!entry_id) + return dns; + + entry_len = strlen(entry_id); + + /* See if its already in our dns cache */ + dns = Curl_hash_pick(data->dns.hostcache, entry_id, entry_len + 1); + + if(dns && (data->set.dns_cache_timeout != -1)) { + /* See whether the returned entry is stale. Done before we release lock */ + struct hostcache_prune_data user; + + time(&user.now); + user.cache_timeout = data->set.dns_cache_timeout; + + if(hostcache_timestamp_remove(&user, dns)) { + infof(data, "Hostname in DNS cache was stale, zapped\n"); + dns = NULL; /* the memory deallocation is being handled by the hash */ + Curl_hash_delete(data->dns.hostcache, entry_id, entry_len + 1); + } + } + + /* free the allocated entry_id again */ + free(entry_id); + + return dns; +} + +/* + * Curl_fetch_addr() fetches a 'Curl_dns_entry' already in the DNS cache. + * + * Curl_resolv() checks initially and multi_runsingle() checks each time + * it discovers the handle in the state WAITRESOLVE whether the hostname + * has already been resolved and the address has already been stored in + * the DNS cache. This short circuits waiting for a lot of pending + * lookups for the same hostname requested by different handles. + * + * Returns the Curl_dns_entry entry pointer or NULL if not in the cache. + * + * The returned data *MUST* be "unlocked" with Curl_resolv_unlock() after + * use, or we'll leak memory! + */ +struct Curl_dns_entry * +Curl_fetch_addr(struct connectdata *conn, + const char *hostname, + int port) +{ + struct Curl_easy *data = conn->data; + struct Curl_dns_entry *dns = NULL; + + if(data->share) + Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE); + + dns = fetch_addr(conn, hostname, port); + + if(dns) + dns->inuse++; /* we use it! */ + + if(data->share) + Curl_share_unlock(data, CURL_LOCK_DATA_DNS); + + return dns; +} + +/* + * Curl_shuffle_addr() shuffles the order of addresses in a 'Curl_addrinfo' + * struct by re-linking its linked list. + * + * The addr argument should be the address of a pointer to the head node of a + * `Curl_addrinfo` list and it will be modified to point to the new head after + * shuffling. + * + * Not declared static only to make it easy to use in a unit test! + * + * @unittest: 1608 + */ +CURLcode Curl_shuffle_addr(struct Curl_easy *data, Curl_addrinfo **addr) +{ + CURLcode result = CURLE_OK; + const int num_addrs = Curl_num_addresses(*addr); + + if(num_addrs > 1) { + Curl_addrinfo **nodes; + infof(data, "Shuffling %i addresses", num_addrs); + + nodes = malloc(num_addrs*sizeof(*nodes)); + if(nodes) { + int i; + unsigned int *rnd; + const size_t rnd_size = num_addrs * sizeof(*rnd); + + /* build a plain array of Curl_addrinfo pointers */ + nodes[0] = *addr; + for(i = 1; i < num_addrs; i++) { + nodes[i] = nodes[i-1]->ai_next; + } + + rnd = malloc(rnd_size); + if(rnd) { + /* Fisher-Yates shuffle */ + if(Curl_rand(data, (unsigned char *)rnd, rnd_size) == CURLE_OK) { + Curl_addrinfo *swap_tmp; + for(i = num_addrs - 1; i > 0; i--) { + swap_tmp = nodes[rnd[i] % (i + 1)]; + nodes[rnd[i] % (i + 1)] = nodes[i]; + nodes[i] = swap_tmp; + } + + /* relink list in the new order */ + for(i = 1; i < num_addrs; i++) { + nodes[i-1]->ai_next = nodes[i]; + } + + nodes[num_addrs-1]->ai_next = NULL; + *addr = nodes[0]; + } + free(rnd); + } + else + result = CURLE_OUT_OF_MEMORY; + free(nodes); + } + else + result = CURLE_OUT_OF_MEMORY; + } + return result; +} + +/* + * Curl_cache_addr() stores a 'Curl_addrinfo' struct in the DNS cache. + * + * When calling Curl_resolv() has resulted in a response with a returned + * address, we call this function to store the information in the dns + * cache etc + * + * Returns the Curl_dns_entry entry pointer or NULL if the storage failed. + */ +struct Curl_dns_entry * +Curl_cache_addr(struct Curl_easy *data, + Curl_addrinfo *addr, + const char *hostname, + int port) +{ + char *entry_id; + size_t entry_len; + struct Curl_dns_entry *dns; + struct Curl_dns_entry *dns2; + + /* shuffle addresses if requested */ + if(data->set.dns_shuffle_addresses) { + CURLcode result = Curl_shuffle_addr(data, &addr); + if(!result) + return NULL; + } + + /* Create an entry id, based upon the hostname and port */ + entry_id = create_hostcache_id(hostname, port); + /* If we can't create the entry id, fail */ + if(!entry_id) + return NULL; + entry_len = strlen(entry_id); + + /* Create a new cache entry */ + dns = calloc(1, sizeof(struct Curl_dns_entry)); + if(!dns) { + free(entry_id); + return NULL; + } + + dns->inuse = 1; /* the cache has the first reference */ + dns->addr = addr; /* this is the address(es) */ + time(&dns->timestamp); + if(dns->timestamp == 0) + dns->timestamp = 1; /* zero indicates CURLOPT_RESOLVE entry */ + + /* Store the resolved data in our DNS cache. */ + dns2 = Curl_hash_add(data->dns.hostcache, entry_id, entry_len + 1, + (void *)dns); + if(!dns2) { + free(dns); + free(entry_id); + return NULL; + } + + dns = dns2; + dns->inuse++; /* mark entry as in-use */ + + /* free the allocated entry_id */ + free(entry_id); + + return dns; +} + +/* + * Curl_resolv() is the main name resolve function within libcurl. It resolves + * a name and returns a pointer to the entry in the 'entry' argument (if one + * is provided). 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. + * + * In debug mode, we specifically test for an interface name "LocalHost" + * and resolve "localhost" instead as a means to permit test cases + * to connect to a local test server with any host name. + * + * Return codes: + * + * CURLRESOLV_ERROR (-1) = error, no pointer + * CURLRESOLV_RESOLVED (0) = OK, pointer provided + * CURLRESOLV_PENDING (1) = waiting for response, no pointer + */ + +int Curl_resolv(struct connectdata *conn, + const char *hostname, + int port, + struct Curl_dns_entry **entry) +{ + struct Curl_dns_entry *dns = NULL; + struct Curl_easy *data = conn->data; + CURLcode result; + int rc = CURLRESOLV_ERROR; /* default to failure */ + + *entry = NULL; + + if(data->share) + Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE); + + dns = fetch_addr(conn, hostname, port); + + if(dns) { + infof(data, "Hostname %s was found in DNS cache\n", hostname); + dns->inuse++; /* we use it! */ + rc = CURLRESOLV_RESOLVED; + } + + if(data->share) + Curl_share_unlock(data, CURL_LOCK_DATA_DNS); + + if(!dns) { + /* The entry was not in the cache. Resolve it to IP address */ + + Curl_addrinfo *addr; + int respwait; + + /* Check what IP specifics the app has requested and if we can provide it. + * If not, bail out. */ + if(!Curl_ipvalid(conn)) + return CURLRESOLV_ERROR; + + /* notify the resolver start callback */ + if(data->set.resolver_start) { + int st; + Curl_set_in_callback(data, true); + st = data->set.resolver_start(data->state.resolver, NULL, + data->set.resolver_start_client); + Curl_set_in_callback(data, false); + if(st) + return CURLRESOLV_ERROR; + } + + /* If Curl_getaddrinfo() returns NULL, 'respwait' might be set to a + non-zero value indicating that we need to wait for the response to the + resolve call */ + addr = Curl_getaddrinfo(conn, +#ifdef DEBUGBUILD + (data->set.str[STRING_DEVICE] + && !strcmp(data->set.str[STRING_DEVICE], + "LocalHost"))?"localhost": +#endif + hostname, port, &respwait); + + if(!addr) { + if(respwait) { + /* the response to our resolve call will come asynchronously at + a later time, good or bad */ + /* First, check that we haven't received the info by now */ + result = Curl_resolver_is_resolved(conn, &dns); + if(result) /* error detected */ + return CURLRESOLV_ERROR; + if(dns) + rc = CURLRESOLV_RESOLVED; /* pointer provided */ + else + rc = CURLRESOLV_PENDING; /* no info yet */ + } + } + else { + if(data->share) + Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE); + + /* we got a response, store it in the cache */ + dns = Curl_cache_addr(data, addr, hostname, port); + + if(data->share) + Curl_share_unlock(data, CURL_LOCK_DATA_DNS); + + if(!dns) + /* returned failure, bail out nicely */ + Curl_freeaddrinfo(addr); + else + rc = CURLRESOLV_RESOLVED; + } + } + + *entry = dns; + + 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); +} +#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, + time_t timeoutms) +{ +#ifdef USE_ALARM_TIMEOUT +#ifdef HAVE_SIGACTION + struct sigaction keep_sigact; /* store the old struct here */ + volatile bool keep_copysig = FALSE; /* whether old sigact has been saved */ + struct sigaction sigact; +#else +#ifdef HAVE_SIGNAL + void (*keep_sigact)(int); /* store the old handler here */ +#endif /* HAVE_SIGNAL */ +#endif /* HAVE_SIGACTION */ + volatile long timeout; + volatile unsigned int prev_alarm = 0; + struct Curl_easy *data = conn->data; +#endif /* USE_ALARM_TIMEOUT */ + int rc; + + *entry = NULL; + + if(timeoutms < 0) + /* got an already expired timeout */ + return CURLRESOLV_TIMEDOUT; + +#ifdef USE_ALARM_TIMEOUT + if(data->set.no_signal) + /* Ignore the timeout when signals are disabled */ + timeout = 0; + else + timeout = (timeoutms > LONG_MAX) ? LONG_MAX : (long)timeoutms; + + if(!timeout) + /* USE_ALARM_TIMEOUT defined, but no timeout actually requested */ + return Curl_resolv(conn, hostname, port, entry); + + if(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. */ + failf(data, + "remaining timeout of %ld too small to resolve via SIGALRM method", + timeout); + return CURLRESOLV_TIMEDOUT; + } + /* 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). + This should be the last thing we do before calling Curl_resolv(), + as otherwise we'd have to worry about variables that get modified + before we invoke Curl_resolv() (and thus use "volatile"). */ + if(sigsetjmp(curl_jmpenv, 1)) { + /* this is coming from a siglongjmp() after an alarm signal */ + failf(data, "name lookup timed out"); + rc = CURLRESOLV_ERROR; + goto clean_up; + } + else { + /************************************************************* + * 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(curlx_sltoui(timeout/1000L)); + } + +#else +#ifndef CURLRES_ASYNCH + if(timeoutms) + infof(conn->data, "timeout on name lookup is not supported\n"); +#else + (void)timeoutms; /* timeoutms not used with an async resolver */ +#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 +clean_up: + + if(!prev_alarm) + /* deactivate a possibly active alarm before uninstalling the handler */ + alarm(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 */ + timediff_t elapsed_secs = Curl_timediff(Curl_now(), + conn->created) / 1000; + + /* the alarm period is counted in even number of seconds */ + unsigned long alarm_set = prev_alarm - elapsed_secs; + + 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); + } +#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 + * one unlock is made for each Curl_resolv() call. + * + * May be called with 'data' == NULL for global cache. + */ +void Curl_resolv_unlock(struct Curl_easy *data, struct Curl_dns_entry *dns) +{ + if(data && data->share) + Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE); + + freednsentry(dns); + + if(data && data->share) + Curl_share_unlock(data, CURL_LOCK_DATA_DNS); +} + +/* + * File-internal: release cache dns entry reference, free if inuse drops to 0 + */ +static void freednsentry(void *freethis) +{ + struct Curl_dns_entry *dns = (struct Curl_dns_entry *) freethis; + DEBUGASSERT(dns && (dns->inuse>0)); + + dns->inuse--; + if(dns->inuse == 0) { + Curl_freeaddrinfo(dns->addr); + free(dns); + } +} + +/* + * Curl_mk_dnscache() inits a new DNS cache and returns success/failure. + */ +int Curl_mk_dnscache(struct curl_hash *hash) +{ + return Curl_hash_init(hash, 7, Curl_hash_str, Curl_str_key_compare, + freednsentry); +} + +/* + * Curl_hostcache_clean() + * + * This _can_ be called with 'data' == NULL but then of course no locking + * can be done! + */ + +void Curl_hostcache_clean(struct Curl_easy *data, + struct curl_hash *hash) +{ + if(data && data->share) + Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE); + + Curl_hash_clean(hash); + + if(data && data->share) + Curl_share_unlock(data, CURL_LOCK_DATA_DNS); +} + + +CURLcode Curl_loadhostpairs(struct Curl_easy *data) +{ + struct curl_slist *hostp; + char hostname[256]; + int port = 0; + + for(hostp = data->change.resolve; hostp; hostp = hostp->next) { + if(!hostp->data) + continue; + if(hostp->data[0] == '-') { + char *entry_id; + size_t entry_len; + + if(2 != sscanf(hostp->data + 1, "%255[^:]:%d", hostname, &port)) { + infof(data, "Couldn't parse CURLOPT_RESOLVE removal entry '%s'!\n", + hostp->data); + continue; + } + + /* Create an entry id, based upon the hostname and port */ + entry_id = create_hostcache_id(hostname, port); + /* If we can't create the entry id, fail */ + if(!entry_id) { + return CURLE_OUT_OF_MEMORY; + } + + entry_len = strlen(entry_id); + + if(data->share) + Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE); + + /* delete entry, ignore if it didn't exist */ + Curl_hash_delete(data->dns.hostcache, entry_id, entry_len + 1); + + if(data->share) + Curl_share_unlock(data, CURL_LOCK_DATA_DNS); + + /* free the allocated entry_id again */ + free(entry_id); + } + else { + struct Curl_dns_entry *dns; + Curl_addrinfo *head = NULL, *tail = NULL; + char *entry_id; + size_t entry_len; + char address[64]; + char *addresses = NULL; + char *addr_begin; + char *addr_end; + char *port_ptr; + char *end_ptr; + char *host_end; + unsigned long tmp_port; + bool error = true; + + host_end = strchr(hostp->data, ':'); + if(!host_end || + ((host_end - hostp->data) >= (ptrdiff_t)sizeof(hostname))) + goto err; + + memcpy(hostname, hostp->data, host_end - hostp->data); + hostname[host_end - hostp->data] = '\0'; + + port_ptr = host_end + 1; + tmp_port = strtoul(port_ptr, &end_ptr, 10); + if(tmp_port > USHRT_MAX || end_ptr == port_ptr || *end_ptr != ':') + goto err; + + port = (int)tmp_port; + addresses = end_ptr + 1; + + while(*end_ptr) { + size_t alen; + Curl_addrinfo *ai; + + addr_begin = end_ptr + 1; + addr_end = strchr(addr_begin, ','); + if(!addr_end) + addr_end = addr_begin + strlen(addr_begin); + end_ptr = addr_end; + + /* allow IP(v6) address within [brackets] */ + if(*addr_begin == '[') { + if(addr_end == addr_begin || *(addr_end - 1) != ']') + goto err; + ++addr_begin; + --addr_end; + } + + alen = addr_end - addr_begin; + if(!alen) + continue; + + if(alen >= sizeof(address)) + goto err; + + memcpy(address, addr_begin, alen); + address[alen] = '\0'; + +#ifndef ENABLE_IPV6 + if(strchr(address, ':')) { + infof(data, "Ignoring resolve address '%s', missing IPv6 support.\n", + address); + continue; + } +#endif + + ai = Curl_str2addr(address, port); + if(!ai) { + infof(data, "Resolve address '%s' found illegal!\n", address); + goto err; + } + + if(tail) { + tail->ai_next = ai; + tail = tail->ai_next; + } + else { + head = tail = ai; + } + } + + if(!head) + goto err; + + error = false; + err: + if(error) { + infof(data, "Couldn't parse CURLOPT_RESOLVE entry '%s'!\n", + hostp->data); + Curl_freeaddrinfo(head); + continue; + } + + /* Create an entry id, based upon the hostname and port */ + entry_id = create_hostcache_id(hostname, port); + /* If we can't create the entry id, fail */ + if(!entry_id) { + Curl_freeaddrinfo(head); + return CURLE_OUT_OF_MEMORY; + } + entry_len = strlen(entry_id); + + if(data->share) + Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE); + + /* See if its already in our dns cache */ + dns = Curl_hash_pick(data->dns.hostcache, entry_id, entry_len + 1); + + /* free the allocated entry_id again */ + free(entry_id); + + if(!dns) { + /* if not in the cache already, put this host in the cache */ + dns = Curl_cache_addr(data, head, hostname, port); + if(dns) { + dns->timestamp = 0; /* mark as added by CURLOPT_RESOLVE */ + /* release the returned reference; the cache itself will keep the + * entry alive: */ + dns->inuse--; + } + } + else { + /* this is a duplicate, free it again */ + infof(data, "RESOLVE %s:%d is already cached, %s not stored!\n", + hostname, port, addresses); + Curl_freeaddrinfo(head); + } + + if(data->share) + Curl_share_unlock(data, CURL_LOCK_DATA_DNS); + + if(!dns) { + Curl_freeaddrinfo(head); + return CURLE_OUT_OF_MEMORY; + } + infof(data, "Added %s:%d:%s to DNS cache\n", + hostname, port, addresses); + } + } + data->change.resolve = NULL; /* dealt with now */ + + return CURLE_OK; +} |