X-Git-Url: https://git.hcoop.net/hcoop/debian/exim4.git/blobdiff_plain/420a0d19af455b8c65ca20e08b500bd9c4995860..d1d56ac364669b9a323ad9494f96398ba502dac0:/src/ip.c diff --git a/src/ip.c b/src/ip.c index b492b9d..bf56466 100644 --- a/src/ip.c +++ b/src/ip.c @@ -2,12 +2,12 @@ * Exim - an Internet mail transport agent * *************************************************/ -/* Copyright (c) University of Cambridge 1995 - 2014 */ +/* Copyright (c) University of Cambridge 1995 - 2017 */ /* See the file NOTICE for conditions of use and distribution. */ /* Functions for doing things with sockets. With the advent of IPv6 this has got messier, so that it's worth pulling out the code into separate functions -that other parts of Exim can call, expecially as there are now several +that other parts of Exim can call, especially as there are now several different places in the code where sockets are used. */ @@ -64,11 +64,11 @@ Returns: nothing - failure provokes a panic-die */ static void -ip_addrinfo(uschar *address, struct sockaddr_in6 *saddr) +ip_addrinfo(const uschar *address, struct sockaddr_in6 *saddr) { #ifdef IPV6_USE_INET_PTON - if (inet_pton(AF_INET6, CS address, &saddr->sin6_addr) != 1) + if (inet_pton(AF_INET6, CCS address, &saddr->sin6_addr) != 1) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "unable to parse \"%s\" as an " "IP address", address); saddr->sin6_family = AF_INET6; @@ -81,7 +81,7 @@ ip_addrinfo(uschar *address, struct sockaddr_in6 *saddr) hints.ai_family = AF_INET6; hints.ai_socktype = SOCK_STREAM; hints.ai_flags = AI_NUMERICHOST; - if ((rc = getaddrinfo(CS address, NULL, &hints, &res)) != 0 || res == NULL) + if ((rc = getaddrinfo(CCS address, NULL, &hints, &res)) != 0 || res == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "unable to parse \"%s\" as an " "IP address: %s", address, (rc == 0)? "NULL result returned" : gai_strerror(rc)); @@ -97,24 +97,11 @@ ip_addrinfo(uschar *address, struct sockaddr_in6 *saddr) * Bind socket to interface and port * *************************************************/ -/* This function binds a socket to a local interface address and port. For a -wildcard IPv6 bind, the address is ":". - -Arguments: - sock the socket - af AF_INET or AF_INET6 - the socket type - address the IP address, in text form - port the IP port (host order) - -Returns: the result of bind() -*/ - int -ip_bind(int sock, int af, uschar *address, int port) +ip_addr(void * sin_, int af, const uschar * address, int port) { -int s_len; -union sockaddr_46 sin; -memset(&sin, 0, sizeof(sin)); +union sockaddr_46 * sin = sin_; +memset(sin, 0, sizeof(*sin)); /* Setup code when using an IPv6 socket. The wildcard address is ":", to ensure an IPv6 socket is used. */ @@ -124,15 +111,13 @@ if (af == AF_INET6) { if (address[0] == ':' && address[1] == 0) { - sin.v6.sin6_family = AF_INET6; - sin.v6.sin6_addr = in6addr_any; + sin->v6.sin6_family = AF_INET6; + sin->v6.sin6_addr = in6addr_any; } else - { - ip_addrinfo(address, &sin.v6); /* Panic-dies on error */ - } - sin.v6.sin6_port = htons(port); - s_len = sizeof(sin.v6); + ip_addrinfo(address, &sin->v6); /* Panic-dies on error */ + sin->v6.sin6_port = htons(port); + return sizeof(sin->v6); } else #else /* HAVE_IPv6 */ @@ -142,17 +127,34 @@ af = af; /* Avoid compiler warning */ /* Setup code when using IPv4 socket. The wildcard address is "". */ { - sin.v4.sin_family = AF_INET; - sin.v4.sin_port = htons(port); - s_len = sizeof(sin.v4); - if (address[0] == 0) - sin.v4.sin_addr.s_addr = (S_ADDR_TYPE)INADDR_ANY; - else - sin.v4.sin_addr.s_addr = (S_ADDR_TYPE)inet_addr(CS address); + sin->v4.sin_family = AF_INET; + sin->v4.sin_port = htons(port); + sin->v4.sin_addr.s_addr = address[0] == 0 + ? (S_ADDR_TYPE)INADDR_ANY + : (S_ADDR_TYPE)inet_addr(CS address); + return sizeof(sin->v4); } +} + + + +/* This function binds a socket to a local interface address and port. For a +wildcard IPv6 bind, the address is ":". + +Arguments: + sock the socket + af AF_INET or AF_INET6 - the socket type + address the IP address, in text form + port the IP port (host order) -/* Now we can call the bind() function */ +Returns: the result of bind() +*/ +int +ip_bind(int sock, int af, uschar *address, int port) +{ +union sockaddr_46 sin; +int s_len = ip_addr(&sin, af, address, port); return bind(sock, (struct sockaddr *)&sin, s_len); } @@ -173,12 +175,14 @@ Arguments: address the remote address, in text form port the remote port timeout a timeout (zero for indefinite timeout) + fastopen TRUE iff TCP_FASTOPEN can be used Returns: 0 on success; -1 on failure, with errno set */ int -ip_connect(int sock, int af, uschar *address, int port, int timeout) +ip_connect(int sock, int af, const uschar *address, int port, int timeout, + BOOL fastopen) { struct sockaddr_in s_in4; struct sockaddr *s_ptr; @@ -208,7 +212,7 @@ IPv6 support. */ memset(&s_in4, 0, sizeof(s_in4)); s_in4.sin_family = AF_INET; s_in4.sin_port = htons(port); - s_in4.sin_addr.s_addr = (S_ADDR_TYPE)inet_addr(CS address); + s_in4.sin_addr.s_addr = (S_ADDR_TYPE)inet_addr(CCS address); s_ptr = (struct sockaddr *)&s_in4; s_len = sizeof(s_in4); } @@ -216,9 +220,34 @@ IPv6 support. */ /* If no connection timeout is set, just call connect() without setting a timer, thereby allowing the inbuilt OS timeout to operate. */ +callout_address = string_sprintf("[%s]:%d", address, port); sigalrm_seen = FALSE; if (timeout > 0) alarm(timeout); -rc = connect(sock, s_ptr, s_len); + +#if defined(TCP_FASTOPEN) && defined(MSG_FASTOPEN) +/* TCP Fast Open, if the system has a cookie from a previous call to +this peer, can send data in the SYN packet. The peer can send data +before it gets our ACK of its SYN,ACK - the latter is useful for +the SMTP banner. Is there any usage where the former might be? +We might extend the ip_connect() args for data if so. For now, +connect in FASTOPEN mode but with zero data. +*/ + +if (fastopen) + { + if ( (rc = sendto(sock, NULL, 0, MSG_FASTOPEN, s_ptr, s_len)) < 0 + && errno == EOPNOTSUPP + ) + { + DEBUG(D_transport) + debug_printf("Tried TCP Fast Open but apparently not enabled by sysctl\n"); + rc = connect(sock, s_ptr, s_len); + } + } +else +#endif + rc = connect(sock, s_ptr, s_len); + save_errno = errno; alarm(0); @@ -226,24 +255,22 @@ alarm(0); can't think of any other way of doing this. It converts a connection refused into a timeout if the timeout is set to 999999. */ -if (running_in_test_harness) +if (running_in_test_harness && save_errno == ECONNREFUSED && timeout == 999999) { - if (save_errno == ECONNREFUSED && timeout == 999999) - { - rc = -1; - save_errno = EINTR; - sigalrm_seen = TRUE; - } + rc = -1; + save_errno = EINTR; + sigalrm_seen = TRUE; } /* Success */ -if (rc >= 0) return 0; +if (rc >= 0) + return 0; /* A failure whose error code is "Interrupted system call" is in fact an externally applied timeout if the signal handler has been run. */ -errno = (save_errno == EINTR && sigalrm_seen)? ETIMEDOUT : save_errno; +errno = save_errno == EINTR && sigalrm_seen ? ETIMEDOUT : save_errno; return -1; } @@ -276,6 +303,7 @@ int namelen, port; host_item shost; host_item *h; int af = 0, fd, fd4 = -1, fd6 = -1; +BOOL fastopen = tcp_fastopen_ok && type == SOCK_STREAM; shost.next = NULL; shost.address = NULL; @@ -289,9 +317,7 @@ namelen = Ustrlen(hostname); if (hostname[0] == '[' && hostname[namelen - 1] == ']') { - uschar * host = string_copy(hostname); - host[namelen - 1] = 0; - host++; + uschar * host = string_copyn(hostname+1, namelen-2); if (string_is_ip_address(host, NULL) == 0) { *errstr = string_sprintf("malformed IP address \"%s\"", hostname); @@ -303,15 +329,15 @@ if (hostname[0] == '[' && /* Otherwise check for an unadorned IP address */ else if (string_is_ip_address(hostname, NULL) != 0) - shost.name = shost.address = string_copy(hostname); + shost.name = shost.address = string_copyn(hostname, namelen); /* Otherwise lookup IP address(es) from the name */ else { - shost.name = string_copy(hostname); - if (host_find_byname(&shost, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, - FALSE) != HOST_FOUND) + shost.name = string_copyn(hostname, namelen); + if (host_find_byname(&shost, NULL, HOST_FIND_QUALIFY_SINGLE, + NULL, FALSE) != HOST_FOUND) { *errstr = string_sprintf("no IP address found for host %s", shost.name); return -1; @@ -320,11 +346,11 @@ else /* Try to connect to the server - test each IP till one works */ -for (h = &shost; h != NULL; h = h->next) +for (h = &shost; h; h = h->next) { - fd = (Ustrchr(h->address, ':') != 0) - ? (fd6 < 0) ? (fd6 = ip_socket(type, af = AF_INET6)) : fd6 - : (fd4 < 0) ? (fd4 = ip_socket(type, af = AF_INET )) : fd4; + fd = Ustrchr(h->address, ':') != 0 + ? fd6 < 0 ? (fd6 = ip_socket(type, af = AF_INET6)) : fd6 + : fd4 < 0 ? (fd4 = ip_socket(type, af = AF_INET )) : fd4; if (fd < 0) { @@ -333,11 +359,12 @@ for (h = &shost; h != NULL; h = h->next) } for(port = portlo; port <= porthi; port++) - if (ip_connect(fd, af, h->address, port, timeout) == 0) + if (ip_connect(fd, af, h->address, port, timeout, fastopen) == 0) { if (fd != fd6) close(fd6); if (fd != fd4) close(fd4); - if (connhost) { + if (connhost) + { h->port = port; *connhost = *h; connhost->next = NULL; @@ -346,14 +373,71 @@ for (h = &shost; h != NULL; h = h->next) } } -*errstr = string_sprintf("failed to connect to %s: " - "couldn't connect to any host: %s", hostname, strerror(errno)); +*errstr = string_sprintf("failed to connect to any address for %s: %s", + hostname, strerror(errno)); bad: close(fd4); close(fd6); return -1; } +int +ip_tcpsocket(const uschar * hostport, uschar ** errstr, int tmo) +{ +int scan; +uschar hostname[256]; +unsigned int portlow, porthigh; + +/* extract host and port part */ +scan = sscanf(CS hostport, "%255s %u-%u", hostname, &portlow, &porthigh); +if (scan != 3) + { + if (scan != 2) + { + *errstr = string_sprintf("invalid socket '%s'", hostport); + return -1; + } + porthigh = portlow; + } + +return ip_connectedsocket(SOCK_STREAM, hostname, portlow, porthigh, + tmo, NULL, errstr); +} + +int +ip_unixsocket(const uschar * path, uschar ** errstr) +{ +int sock; +struct sockaddr_un server; + +if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) + { + *errstr = US"can't open UNIX socket."; + return -1; + } + +callout_address = string_copy(path); +server.sun_family = AF_UNIX; +Ustrncpy(server.sun_path, path, sizeof(server.sun_path)-1); +server.sun_path[sizeof(server.sun_path)-1] = '\0'; +if (connect(sock, (struct sockaddr *) &server, sizeof(server)) < 0) + { + int err = errno; + (void)close(sock); + *errstr = string_sprintf("unable to connect to UNIX socket (%s): %s", + path, strerror(err)); + return -1; + } +return sock; +} + +int +ip_streamsocket(const uschar * spec, uschar ** errstr, int tmo) +{ +return *spec == '/' + ? ip_unixsocket(spec, errstr) : ip_tcpsocket(spec, errstr, tmo); +} + /************************************************* * Set keepalive on a socket * *************************************************/ @@ -369,7 +453,7 @@ Returns: nothing */ void -ip_keepalive(int sock, uschar *address, BOOL torf) +ip_keepalive(int sock, const uschar *address, BOOL torf) { int fodder = 1; if (setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, @@ -384,39 +468,36 @@ if (setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, * Receive from a socket with timeout * *************************************************/ -/* The timeout is implemented using select(), and we loop to cover select() -getting interrupted, and the possibility of select() returning with a positive -result but no ready descriptor. Is this in fact possible? - +/* Arguments: - sock the socket - buffer to read into - bufsize the buffer size - timeout the timeout - -Returns: > 0 => that much data read - <= 0 on error or EOF; errno set - zero for EOF + fd the file descriptor + timeout the timeout, seconds +Returns: TRUE => ready for i/o + FALSE => timed out, or other error */ - -int -ip_recv(int sock, uschar *buffer, int buffsize, int timeout) +BOOL +fd_ready(int fd, int timeout) { fd_set select_inset; -struct timeval tv; time_t start_recv = time(NULL); +int time_left = timeout; int rc; +if (time_left <= 0) + { + errno = ETIMEDOUT; + return FALSE; + } /* Wait until the socket is ready */ -for (;;) +do { + struct timeval tv = { time_left, 0 }; FD_ZERO (&select_inset); - FD_SET (sock, &select_inset); - tv.tv_sec = timeout; - tv.tv_usec = 0; + FD_SET (fd, &select_inset); - DEBUG(D_transport) debug_printf("waiting for data on socket\n"); - rc = select(sock + 1, (SELECT_ARG2_TYPE *)&select_inset, NULL, NULL, &tv); + /*DEBUG(D_transport) debug_printf("waiting for data on fd\n");*/ + rc = select(fd + 1, (SELECT_ARG2_TYPE *)&select_inset, NULL, NULL, &tv); /* If some interrupt arrived, just retry. We presume this to be rare, but it can happen (e.g. the SIGUSR1 signal sent by exiwhat causes @@ -425,28 +506,52 @@ for (;;) Aug 2004: Somebody set up a cron job that ran exiwhat every 2 minutes, making the interrupt not at all rare. Since the timeout is typically more than 2 minutes, the effect was to block the timeout completely. To prevent this - happening again, we do an explicit time test. */ + happening again, we do an explicit time test and adjust the timeout + accordingly */ if (rc < 0 && errno == EINTR) { DEBUG(D_transport) debug_printf("EINTR while waiting for socket data\n"); - if (time(NULL) - start_recv < timeout) continue; - DEBUG(D_transport) debug_printf("total wait time exceeds timeout\n"); - } - /* Handle a timeout, and treat any other select error as a timeout, including - an EINTR when we have been in this loop for longer than timeout. */ + /* Watch out, 'continue' jumps to the condition, not to the loops top */ + time_left = timeout - (time(NULL) - start_recv); + if (time_left > 0) continue; + } if (rc <= 0) { errno = ETIMEDOUT; - return -1; + return FALSE; } - /* If the socket is ready, break out of the loop. */ - - if (FD_ISSET(sock, &select_inset)) break; + /* Checking the FD_ISSET is not enough, if we're interrupted, the + select_inset may still contain the 'input'. */ } +while (rc < 0 || !FD_ISSET(fd, &select_inset)); +return TRUE; +} + +/* The timeout is implemented using select(), and we loop to cover select() +getting interrupted, and the possibility of select() returning with a positive +result but no ready descriptor. Is this in fact possible? + +Arguments: + sock the socket + buffer to read into + bufsize the buffer size + timeout the timeout + +Returns: > 0 => that much data read + <= 0 on error or EOF; errno set - zero for EOF +*/ + +int +ip_recv(int sock, uschar *buffer, int buffsize, int timeout) +{ +int rc; + +if (!fd_ready(sock, timeout)) + return -1; /* The socket is ready, read from it (via TLS if it's active). On EOF (i.e. close down of the connection), set errno to zero; otherwise leave it alone. */ @@ -625,13 +730,9 @@ while (last > first) return TRUE; } else if (c > 0) - { first = middle + 1; - } else - { last = middle; - } } return FALSE; } @@ -646,3 +747,5 @@ for (i=0; i < dscp_table_size; ++i) /* End of ip.c */ +/* vi: aw ai sw=2 +*/