X-Git-Url: https://vcs.fsf.org/?a=blobdiff_plain;f=src%2Fsrc%2Fip.c;h=04b86060fa42cd23e31ed36b0641fb71e509cad3;hb=3cc3f7625d68c169d47dadbefa74233e5fe7ed55;hp=af57fa411ca5d825bd3f0654e91b272cb6eca4b3;hpb=184e88237dea64ce48076cdd0184612d057cbafd;p=exim.git diff --git a/src/src/ip.c b/src/src/ip.c index af57fa411..04b86060f 100644 --- a/src/src/ip.c +++ b/src/src/ip.c @@ -1,10 +1,8 @@ -/* $Cambridge: exim/src/src/ip.c,v 1.7 2007/01/08 10:50:18 ph10 Exp $ */ - /************************************************* * Exim - an Internet mail transport agent * *************************************************/ -/* Copyright (c) University of Cambridge 1995 - 2007 */ +/* Copyright (c) University of Cambridge 1995 - 2016 */ /* See the file NOTICE for conditions of use and distribution. */ /* Functions for doing things with sockets. With the advent of IPv6 this has @@ -66,11 +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; @@ -83,7 +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)); @@ -99,24 +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. */ @@ -126,15 +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 */ @@ -144,17 +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); } @@ -174,13 +174,13 @@ Arguments: af AF_INET6 or AF_INET for the socket type address the remote address, in text form port the remote port - timeout a timeout + timeout a timeout (zero for indefinite timeout) 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) { struct sockaddr_in s_in4; struct sockaddr *s_ptr; @@ -210,7 +210,7 @@ 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); } @@ -218,6 +218,7 @@ 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); @@ -228,29 +229,188 @@ 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; } +/************************************************* +* Create connected socket to remote host * +*************************************************/ + +/* Create a socket and connect to host (name or number, ipv6 ok) + at one of port-range. + +Arguments: + type SOCK_DGRAM or SOCK_STREAM + af AF_INET6 or AF_INET for the socket type + address the remote address, in text form + portlo,porthi the remote port range + timeout a timeout + connhost if not NULL, host_item filled in with connection details + errstr pointer for allocated string on error + +Return: + socket fd, or -1 on failure (having allocated an error string) +*/ +int +ip_connectedsocket(int type, const uschar * hostname, int portlo, int porthi, + int timeout, host_item * connhost, uschar ** errstr) +{ +int namelen, port; +host_item shost; +host_item *h; +int af = 0, fd, fd4 = -1, fd6 = -1; + +shost.next = NULL; +shost.address = NULL; +shost.port = portlo; +shost.mx = -1; + +namelen = Ustrlen(hostname); + +/* Anything enclosed in [] must be an IP address. */ + +if (hostname[0] == '[' && + hostname[namelen - 1] == ']') + { + uschar * host = string_copyn(hostname+1, namelen-2); + if (string_is_ip_address(host, NULL) == 0) + { + *errstr = string_sprintf("malformed IP address \"%s\"", hostname); + return -1; + } + shost.name = shost.address = host; + } + +/* Otherwise check for an unadorned IP address */ + +else if (string_is_ip_address(hostname, NULL) != 0) + shost.name = shost.address = string_copyn(hostname, namelen); + +/* Otherwise lookup IP address(es) from the name */ + +else + { + 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; + } + } + +/* Try to connect to the server - test each IP till one works */ + +for (h = &shost; h != NULL; 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; + + if (fd < 0) + { + *errstr = string_sprintf("failed to create socket: %s", strerror(errno)); + goto bad; + } + + for(port = portlo; port <= porthi; port++) + if (ip_connect(fd, af, h->address, port, timeout) == 0) + { + if (fd != fd6) close(fd6); + if (fd != fd4) close(fd4); + if (connhost) + { + h->port = port; + *connhost = *h; + connhost->next = NULL; + } + return fd; + } + } + +*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 * *************************************************/ @@ -266,7 +426,7 @@ 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, @@ -281,39 +441,36 @@ 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; -int start_recv = time(NULL); +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 @@ -322,35 +479,61 @@ 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. */ #ifdef SUPPORT_TLS -if (tls_active == sock) - rc = tls_read(buffer, buffsize); +if (tls_out.active == sock) + rc = tls_read(FALSE, buffer, buffsize); +else if (tls_in.active == sock) + rc = tls_read(TRUE, buffer, buffsize); else #endif rc = recv(sock, buffer, buffsize, 0); @@ -361,4 +544,181 @@ return -1; } + + +/************************************************* +* Lookup address family of potential socket * +*************************************************/ + +/* Given a file-descriptor, check to see if it's a socket and, if so, +return the address family; detects IPv4 vs IPv6. If not a socket then +return -1. + +The value 0 is typically AF_UNSPEC, which should not be seen on a connected +fd. If the return is -1, the errno will be from getsockname(); probably +ENOTSOCK or ECONNRESET. + +Arguments: socket-or-not fd +Returns: address family or -1 +*/ + +int +ip_get_address_family(int fd) +{ +struct sockaddr_storage ss; +socklen_t sslen = sizeof(ss); + +if (getsockname(fd, (struct sockaddr *) &ss, &sslen) < 0) + return -1; + +return (int) ss.ss_family; +} + + + + +/************************************************* +* Lookup DSCP settings for a socket * +*************************************************/ + +struct dscp_name_tableentry { + const uschar *name; + int value; +}; +/* Keep both of these tables sorted! */ +static struct dscp_name_tableentry dscp_table[] = { +#ifdef IPTOS_DSCP_AF11 + { CUS"af11", IPTOS_DSCP_AF11 }, + { CUS"af12", IPTOS_DSCP_AF12 }, + { CUS"af13", IPTOS_DSCP_AF13 }, + { CUS"af21", IPTOS_DSCP_AF21 }, + { CUS"af22", IPTOS_DSCP_AF22 }, + { CUS"af23", IPTOS_DSCP_AF23 }, + { CUS"af31", IPTOS_DSCP_AF31 }, + { CUS"af32", IPTOS_DSCP_AF32 }, + { CUS"af33", IPTOS_DSCP_AF33 }, + { CUS"af41", IPTOS_DSCP_AF41 }, + { CUS"af42", IPTOS_DSCP_AF42 }, + { CUS"af43", IPTOS_DSCP_AF43 }, + { CUS"ef", IPTOS_DSCP_EF }, +#endif +#ifdef IPTOS_LOWCOST + { CUS"lowcost", IPTOS_LOWCOST }, +#endif + { CUS"lowdelay", IPTOS_LOWDELAY }, +#ifdef IPTOS_MINCOST + { CUS"mincost", IPTOS_MINCOST }, +#endif + { CUS"reliability", IPTOS_RELIABILITY }, + { CUS"throughput", IPTOS_THROUGHPUT } +}; +static int dscp_table_size = + sizeof(dscp_table) / sizeof(struct dscp_name_tableentry); + +/* DSCP values change by protocol family, and so do the options used for +setsockopt(); this utility does all the lookups. It takes an unexpanded +option string, expands it, strips off affix whitespace, then checks if it's +a number. If all of what's left is a number, then that's how the option will +be parsed and success/failure is a range check. If it's not all a number, +then it must be a supported keyword. + +Arguments: + dscp_name a string, so far unvalidated + af address_family in use + level setsockopt level to use + optname setsockopt name to use + dscp_value value for dscp_name + +Returns: TRUE if okay to setsockopt(), else FALSE + +*level and *optname may be set even if FALSE is returned +*/ + +BOOL +dscp_lookup(const uschar *dscp_name, int af, + int *level, int *optname, int *dscp_value) +{ +uschar *dscp_lookup, *p; +int first, last; +long rawlong; + +if (af == AF_INET) + { + *level = IPPROTO_IP; + *optname = IP_TOS; + } +#if HAVE_IPV6 && defined(IPV6_TCLASS) +else if (af == AF_INET6) + { + *level = IPPROTO_IPV6; + *optname = IPV6_TCLASS; + } +#endif +else + { + DEBUG(D_transport) + debug_printf("Unhandled address family %d in dscp_lookup()\n", af); + return FALSE; + } +if (!dscp_name) + { + DEBUG(D_transport) + debug_printf("[empty DSCP]\n"); + return FALSE; + } +dscp_lookup = expand_string(US dscp_name); +if (dscp_lookup == NULL || *dscp_lookup == '\0') + return FALSE; + +p = dscp_lookup + Ustrlen(dscp_lookup) - 1; +while (isspace(*p)) *p-- = '\0'; +while (isspace(*dscp_lookup) && dscp_lookup < p) dscp_lookup++; +if (*dscp_lookup == '\0') + return FALSE; + +rawlong = Ustrtol(dscp_lookup, &p, 0); +if (p != dscp_lookup && *p == '\0') + { + /* We have six bits available, which will end up shifted to fit in 0xFC mask. + RFC 2597 defines the values unshifted. */ + if (rawlong < 0 || rawlong > 0x3F) + { + DEBUG(D_transport) + debug_printf("DSCP value %ld out of range, ignored.\n", rawlong); + return FALSE; + } + *dscp_value = rawlong << 2; + return TRUE; + } + +first = 0; +last = dscp_table_size; +while (last > first) + { + int middle = (first + last)/2; + int c = Ustrcmp(dscp_lookup, dscp_table[middle].name); + if (c == 0) + { + *dscp_value = dscp_table[middle].value; + return TRUE; + } + else if (c > 0) + first = middle + 1; + else + last = middle; + } +return FALSE; +} + +void +dscp_list_to_stream(FILE *stream) +{ +int i; +for (i=0; i < dscp_table_size; ++i) + fprintf(stream, "%s\n", dscp_table[i].name); +} + + /* End of ip.c */ +/* vi: aw ai sw=2 +*/