From 090b55c100be4364ac035b5a1b7440cf94e71904 Mon Sep 17 00:00:00 2001 From: Kim Vandry Date: Wed, 3 Apr 2013 16:06:51 -0400 Subject: connect: treat an interface bindlocal() problem as a non-fatal error I am using curl_easy_setopt(CURLOPT_INTERFACE, "if!something") to force transfers to use a particular interface but the transfer fails with CURLE_INTERFACE_FAILED, "Failed binding local connection end" if the interface I specify has no IPv6 address. The cause is as follows: The remote hostname resolves successfully and has an IPv6 address and an IPv4 address. cURL attempts to connect to the IPv6 address first. bindlocal (in lib/connect.c) fails because Curl_if2ip cannot find an IPv6 address on the interface. This is a fatal error in singleipconnect() This change will make cURL try the next IP address in the list. Also included are two changes related to IPv6 address scope: - Filter the choice of address in Curl_if2ip to only consider addresses with the same scope ID as the connection address (mismatched scope for local and remote address does not result in a working connection). - bindlocal was ignoring the scope ID of addresses returned by Curl_if2ip . Now it uses them. Bug: http://curl.haxx.se/bug/view.cgi?id=1189 --- lib/if2ip.c | 92 +++++++++++++++++++++++++++++++++++++------------------------ 1 file changed, 56 insertions(+), 36 deletions(-) (limited to 'lib/if2ip.c') diff --git a/lib/if2ip.c b/lib/if2ip.c index cc191201e..99fa01106 100644 --- a/lib/if2ip.c +++ b/lib/if2ip.c @@ -83,42 +83,59 @@ bool Curl_if_is_interface_name(const char *interf) return result; } -char *Curl_if2ip(int af, const char *interf, char *buf, int buf_size) +if2ip_result_t Curl_if2ip(int af, unsigned int remote_scope, + const char *interf, char *buf, int buf_size) { struct ifaddrs *iface, *head; - char *ip = NULL; + if2ip_result_t res = IF2IP_NOT_FOUND; if(getifaddrs(&head) >= 0) { for(iface=head; iface != NULL; iface=iface->ifa_next) { - if((iface->ifa_addr != NULL) && - (iface->ifa_addr->sa_family == af) && - curl_strequal(iface->ifa_name, interf)) { - void *addr; - char scope[12]=""; - char ipstr[64]; + if(iface->ifa_addr != NULL) { + if(iface->ifa_addr->sa_family == af) { + if(curl_strequal(iface->ifa_name, interf)) { + void *addr; + char *ip; + char scope[12]=""; + char ipstr[64]; #ifdef ENABLE_IPV6 - if(af == AF_INET6) { - unsigned int scopeid = 0; - addr = &((struct sockaddr_in6 *)iface->ifa_addr)->sin6_addr; + if(af == AF_INET6) { + unsigned int scopeid = 0; + addr = &((struct sockaddr_in6 *)iface->ifa_addr)->sin6_addr; #ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID - /* Include the scope of this interface as part of the address */ - scopeid = ((struct sockaddr_in6 *)iface->ifa_addr)->sin6_scope_id; + /* Include the scope of this interface as part of the address */ + scopeid = + ((struct sockaddr_in6 *)iface->ifa_addr)->sin6_scope_id; #endif - if(scopeid) - snprintf(scope, sizeof(scope), "%%%u", scopeid); - } - else + if(scopeid != remote_scope) { + /* We are interested only in interface addresses whose + scope ID matches the remote address we want to + connect to: global (0) for global, link-local for + link-local, etc... */ + if(res == IF2IP_NOT_FOUND) res = IF2IP_AF_NOT_SUPPORTED; + continue; + } + if(scopeid) + snprintf(scope, sizeof(scope), "%%%u", scopeid); + } + else #endif - addr = &((struct sockaddr_in *)iface->ifa_addr)->sin_addr; - ip = (char *) Curl_inet_ntop(af, addr, ipstr, sizeof(ipstr)); - snprintf(buf, buf_size, "%s%s", ip, scope); - ip = buf; - break; + addr = &((struct sockaddr_in *)iface->ifa_addr)->sin_addr; + res = IF2IP_FOUND; + ip = (char *) Curl_inet_ntop(af, addr, ipstr, sizeof(ipstr)); + snprintf(buf, buf_size, "%s%s", ip, scope); + break; + } + } + else if((res == IF2IP_NOT_FOUND) && + curl_strequal(iface->ifa_name, interf)) { + res = IF2IP_AF_NOT_SUPPORTED; + } } } freeifaddrs(head); } - return ip; + return res; } #elif defined(HAVE_IOCTL_SIOCGIFADDR) @@ -128,30 +145,29 @@ bool Curl_if_is_interface_name(const char *interf) /* This is here just to support the old interfaces */ char buf[256]; - char *ip = Curl_if2ip(AF_INET, interf, buf, sizeof(buf)); - - return (ip != NULL) ? TRUE : FALSE; + return (Curl_if2ip(AF_INET, 0, interf, buf, sizeof(buf)) == + IF2IP_NOT_FOUND) ? FALSE : TRUE; } -char *Curl_if2ip(int af, const char *interf, char *buf, int buf_size) +if2ip_result_t Curl_if2ip(int af, unsigned int remote_scope, + const char *interf, char *buf, int buf_size) { struct ifreq req; struct in_addr in; struct sockaddr_in *s; curl_socket_t dummy; size_t len; - char *ip; if(!interf || (af != AF_INET)) - return NULL; + return IF2IP_NOT_FOUND; len = strlen(interf); if(len >= sizeof(req.ifr_name)) - return NULL; + return IF2IP_NOT_FOUND; dummy = socket(AF_INET, SOCK_STREAM, 0); if(CURL_SOCKET_BAD == dummy) - return NULL; + return IF2IP_NOT_FOUND; memset(&req, 0, sizeof(req)); memcpy(req.ifr_name, interf, len+1); @@ -159,15 +175,18 @@ char *Curl_if2ip(int af, const char *interf, char *buf, int buf_size) if(ioctl(dummy, SIOCGIFADDR, &req) < 0) { sclose(dummy); - return NULL; + /* With SIOCGIFADDR, we cannot tell the difference between an interface + that does not exist and an interface that has no address of the + correct family. Assume the interface does not exist */ + return IF2IP_NOT_FOUND; } s = (struct sockaddr_in *)&req.ifr_addr; memcpy(&in, &s->sin_addr, sizeof(in)); - ip = (char *) Curl_inet_ntop(s->sin_family, &in, buf, buf_size); + Curl_inet_ntop(s->sin_family, &in, buf, buf_size); sclose(dummy); - return ip; + return IF2IP_FOUND; } #else @@ -179,13 +198,14 @@ bool Curl_if_is_interface_name(const char *interf) return FALSE; } -char *Curl_if2ip(int af, const char *interf, char *buf, int buf_size) +if2ip_result_t Curl_if2ip(int af, unsigned int remote_scope, + const char *interf, char *buf, int buf_size) { (void) af; (void) interf; (void) buf; (void) buf_size; - return NULL; + return IF2IP_NOT_FOUND; } #endif -- cgit v1.2.3