X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=net.c;h=ccb9632de9a30f566450cea2e4a62e29bd0c530f;hp=b44d1d3e5d3a2012b1dfe135ddeec74d10b0fe58;hb=06e47cd5c6d93afa59eadfa6e2ee89b7415180e0;hpb=8cf2884a87db0eca0aa2f382c9850335332682b3 diff --git a/net.c b/net.c index b44d1d3e..ccb9632d 100644 --- a/net.c +++ b/net.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2005-2009 Andre Noll + * Copyright (C) 2005-2013 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ @@ -25,13 +25,10 @@ #define AI_ADDRCONFIG 0 #endif -#include #include -#include #include "para.h" #include "error.h" -#include "crypt.h" #include "net.h" #include "string.h" #include "list.h" @@ -145,9 +142,9 @@ static bool host_string_ok(const char *host) * \param hostlen The maximum length of \a host. * \param port To return the port number (if any) of \a url. * - * \return Pointer to \a host, or NULL if failed. - * If NULL is returned, \a host and \a portnum are undefined. If no - * port number was present in \a url, \a portnum is set to -1. + * \return Pointer to \a host, or \p NULL if failed. If \p NULL is returned, + * \a host and \a port are undefined. If no port number was present in \a url, + * \a port is set to -1. * * \sa RFC 3986, 3.2.2/3.2.3 */ @@ -171,16 +168,16 @@ char *parse_url(const char *url, if (*o++ != ']' || (*o != '\0' && *o != ':')) goto failed; } else { - for (; (*c = *o == ':'? '\0' : *o); c++, o++) - if (c == end) + for (; (*c = *o == ':'? '\0' : *o); c++, o++) { + if (c == end && o[1]) goto failed; + } } if (*o == ':') if (para_atoi32(++o, port) < 0 || *port < 0 || *port > 0xffff) goto failed; - if (host_string_ok(host)) return host; failed: @@ -267,6 +264,12 @@ struct flowopts { struct list_head sockopts; }; +/** + * Allocate and initialize a flowopt queue. + * + * \return A new structure to be passed to \ref flowopt_add(). It is + * automatically deallocated in \ref makesock(). + */ struct flowopts *flowopt_new(void) { struct flowopts *new = para_malloc(sizeof(*new)); @@ -279,7 +282,7 @@ struct flowopts *flowopt_new(void) * Append new socket option to flowopt queue. * * \param fo The flowopt queue to append to. - * \param lev Level at which \opt resides. + * \param lev Level at which \a opt resides. * \param opt New option to add. * \param name Stringified name of \a opt. * \param val The value to set \a opt to. @@ -288,7 +291,7 @@ struct flowopts *flowopt_new(void) * \sa setsockopt(2) */ void flowopt_add(struct flowopts *fo, int lev, int opt, - char *name, const void *val, int len) + const char *name, const void *val, int len) { struct pre_conn_opt *new = para_malloc(sizeof(*new)); @@ -308,14 +311,6 @@ void flowopt_add(struct flowopts *fo, int lev, int opt, list_add_tail(&new->node, &fo->sockopts); } -void flowopt_add_bool(struct flowopts *fo, int lev, int opt, - char *optname, bool on_or_off) -{ - int on = on_or_off; /* kernel takes 'int' */ - - flowopt_add(fo, lev, opt, optname, &on, sizeof(on)); -} - /** Set the entire bunch of pre-connection options at once. */ static void flowopt_setopts(int sockfd, struct flowopts *fo) { @@ -348,76 +343,91 @@ static void flowopt_cleanup(struct flowopts *fo) free(fo); } -/** - * Resolve IPv4/IPv6 address and create a ready-to-use active or passive socket. +/* + * Resolve an IPv4/IPv6 address. * - * \param l3type The layer-3 type (\p AF_INET, \p AF_INET6, \p AF_UNSPEC). * \param l4type The layer-4 type (\p IPPROTO_xxx). - * \param passive Whether this is a passive (1) or active (0) socket. + * \param passive Whether \p AI_PASSIVE should be included as hint. * \param host Remote or local hostname or IPv/6 address string. - * \param port_number Decimal port number. - * \param fo Socket options to be set before making the connection. + * \param port_number Used to set the port in each returned address structure. + * \param result addrinfo structures are returned here. * - * This creates a ready-made IPv4/v6 socket structure after looking up the - * necessary parameters. The interpretation of \a host depends on the value of - * \a passive: - * - on a passive socket host is interpreted as an interface IPv4/6 address - * (can be left NULL); - * - on an active socket, \a host is the peer DNS name or IPv4/6 address - * to connect to; - * - \a port_number is in either case the numeric port number (not service - * string). - * - * Furthermore, bind(2) is called on passive sockets, and connect(2) on active - * sockets. The algorithm tries all possible address combinations until it - * succeeds. If \a fo is supplied, options are set and cleanup is performed. - * - * \return This function returns 1 on success and \a -E_ADDRESS_LOOKUP when no - * matching connection could be set up (with details in the error log). - * - * \sa ipv6(7), getaddrinfo(3), bind(2), connect(2). + * The interpretation of \a host depends on the value of \a passive. On a + * passive socket host is interpreted as an interface IPv4/6 address (can be + * left NULL). On an active socket, \a host is the peer DNS name or IPv4/6 + * address to connect to. + * + * \return Standard. + * + * \sa getaddrinfo(3). */ -int makesock(unsigned l4type, bool passive, - const char *host, uint16_t port_number, - struct flowopts *fo) +static int lookup_address(unsigned l4type, bool passive, const char *host, + int port_number, struct addrinfo **result) { - struct addrinfo *local = NULL, *src, - *remote = NULL, *dst, hints; - unsigned int l3type = AF_UNSPEC; - int rc, on = 1, sockfd = -1, - socktype = sock_type(l4type); + int ret; char port[6]; /* port number has at most 5 digits */ + struct addrinfo *addr = NULL, hints; - sprintf(port, "%u", port_number); + *result = NULL; + sprintf(port, "%u", port_number & 0xffff); /* Set up address hint structure */ memset(&hints, 0, sizeof(hints)); - hints.ai_family = l3type; - hints.ai_socktype = socktype; - /* + hints.ai_family = AF_UNSPEC; + hints.ai_socktype = sock_type(l4type); + /* * getaddrinfo does not support SOCK_DCCP, so for the sake of lookup * (and only then) pretend to be UDP. */ if (l4type == IPPROTO_DCCP) hints.ai_socktype = SOCK_DGRAM; - /* only use addresses available on the host */ hints.ai_flags = AI_ADDRCONFIG; - if (l3type == AF_INET6) - /* use v4-mapped-v6 if no v6 addresses found */ - hints.ai_flags |= AI_V4MAPPED | AI_ALL; - if (passive && host == NULL) hints.ai_flags |= AI_PASSIVE; - /* Obtain local/remote address information */ - if ((rc = getaddrinfo(host, port, &hints, passive ? &local : &remote))) { - PARA_ERROR_LOG("can not resolve %s address %s#%s: %s.\n", - layer4_name(l4type), - host? host : (passive? "[loopback]" : "[localhost]"), - port, gai_strerror(rc)); + ret = getaddrinfo(host, port, &hints, &addr); + if (ret != 0) { + PARA_ERROR_LOG("can not resolve %s address %s#%s: %s\n", + layer4_name(l4type), + host? host : (passive? "[loopback]" : "[localhost]"), + port, gai_strerror(ret)); return -E_ADDRESS_LOOKUP; } + *result = addr; + return 1; +} + +/** + * Resolve IPv4/IPv6 address and create a ready-to-use active or passive socket. + * + * \param l4type The layer-4 type (\p IPPROTO_xxx). + * \param passive Whether this is a passive or active socket. + * \param host Passed to \ref \a lookup_address(). + * \param port_number Passed to \ref \a lookup_address(). + * \param fo Socket options to be set before making the connection. + * + * This creates a ready-made IPv4/v6 socket structure after looking up the + * necessary parameters. + * + * bind(2) is called on passive sockets, and connect(2) on active sockets. The + * algorithm tries all possible address combinations until it succeeds. If \a + * fo is supplied, options are set and cleanup is performed. + * + * \return Standard. + * + * \sa \ref lookup_address(), ipv6(7), getaddrinfo(3), bind(2), connect(2). + */ +int makesock(unsigned l4type, bool passive, + const char *host, uint16_t port_number, + struct flowopts *fo) +{ + struct addrinfo *local = NULL, *src = NULL, *remote = NULL, *dst = NULL; + int rc, on = 1, sockfd = -1; + rc = lookup_address(l4type, passive, host, port_number, passive? + &local : &remote); + if (rc < 0) + goto out; /* Iterate over all src/dst combination, exhausting dst first */ for (src = local, dst = remote; src != NULL || dst != NULL; /* no op */ ) { if (src && dst && src->ai_family == AF_INET @@ -425,7 +435,7 @@ int makesock(unsigned l4type, bool passive, goto get_next_dst; /* v4 -> v6 is not possible */ sockfd = socket(src ? src->ai_family : dst->ai_family, - socktype, l4type); + sock_type(l4type), l4type); if (sockfd < 0) goto get_next_dst; @@ -437,9 +447,11 @@ int makesock(unsigned l4type, bool passive, if (passive && setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) { rc = errno; + close(sockfd); PARA_ERROR_LOG("can not set SO_REUSEADDR: %s\n", strerror(rc)); - return -ERRNO_TO_PARA_ERROR(rc); + rc = -ERRNO_TO_PARA_ERROR(rc); + break; } flowopt_setopts(sockfd, fo); @@ -462,6 +474,7 @@ get_next_src: if (src && (src = src->ai_next)) /* restart inner loop */ dst = remote; } +out: if (local) freeaddrinfo(local); if (remote) @@ -469,11 +482,12 @@ get_next_src: flowopt_cleanup(fo); if (src == NULL && dst == NULL) { - rc = errno; - PARA_ERROR_LOG("can not create %s socket %s#%s.\n", + if (rc >= 0) + rc = -E_MAKESOCK; + PARA_ERROR_LOG("can not create %s socket %s#%d.\n", layer4_name(l4type), host? host : (passive? - "[loopback]" : "[localhost]"), port); - return -ERRNO_TO_PARA_ERROR(rc); + "[loopback]" : "[localhost]"), port_number); + return rc; } return sockfd; } @@ -521,6 +535,14 @@ static socklen_t salen(const struct sockaddr *sa) : sizeof(struct sockaddr_in); } +/** True if @ss holds a v6-mapped-v4 address (RFC 4291, 2.5.5.2) */ +static bool SS_IS_ADDR_V4MAPPED(const struct sockaddr_storage *ss) +{ + const struct sockaddr_in6 *ia6 = (const struct sockaddr_in6 *)ss; + + return ss->ss_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&ia6->sin6_addr); +} + /** * Process IPv4/v6 address, turn v6-mapped-v4 address into normal IPv4 address. * \param ss Container of IPv4/6 address. @@ -531,11 +553,10 @@ static socklen_t salen(const struct sockaddr *sa) static const struct sockaddr * normalize_ip_address(const struct sockaddr_storage *ss) { - const struct sockaddr_in6 *ia6 = (const struct sockaddr_in6 *)ss; - assert(ss->ss_family == AF_INET || ss->ss_family == AF_INET6); - if (ss->ss_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&ia6->sin6_addr)) { + if (SS_IS_ADDR_V4MAPPED(ss)) { + const struct sockaddr_in6 *ia6 = (const struct sockaddr_in6 *)ss; static struct sockaddr_in ia; ia.sin_family = AF_INET; @@ -547,31 +568,49 @@ normalize_ip_address(const struct sockaddr_storage *ss) } /** - * Print numeric host and port number (beware - uses static char). + * Generic/fallback MTU values + * + * These are taken from RFC 1122, RFC 2460, and RFC 5405. + * - RFC 1122, 3.3.3 defines EMTU_S ("Effective MTU for sending") and recommends + * to use an EMTU_S size of of 576 bytes if the IPv4 path MTU is unknown; + * - RFC 2460, 5. requires a minimum IPv6 MTU of 1280 bytes; + * - RFC 5405, 3.2 recommends that if path MTU discovery is not done, + * UDP senders should use the respective minimum values of EMTU_S. + */ +static inline int generic_mtu(const int af_type) +{ + return af_type == AF_INET6 ? 1280 : 576; +} + +/** Crude approximation of IP header overhead - neglecting options. */ +static inline int estimated_header_overhead(const int af_type) +{ + return af_type == AF_INET6 ? 40 : 20; +} + +/** + * Get the maximum transport-layer message size (MMS_S). + * + * \param sockfd The socket file descriptor. * - * \param sa The IPv4/IPv6 socket address to use. + * The socket must be connected. See RFC 1122, 3.3.3. If the protocol familiy + * could not be determined, \p AF_INET is assumed. * - * \sa getnameinfo(3), services(5), nsswitch.conf(5) + * \return The maximum message size of the address family type. */ -static char *host_and_port(const struct sockaddr_storage *ss) +int generic_max_transport_msg_size(int sockfd) { - const struct sockaddr *sa = normalize_ip_address(ss); - char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV]; - static char output[sizeof(hbuf) + sizeof(sbuf) + 2]; - int ret; + struct sockaddr_storage ss; + socklen_t sslen = sizeof(ss); + int af_type = AF_INET; - ret = getnameinfo(sa, salen(sa), - hbuf, sizeof(hbuf), - sbuf, sizeof(sbuf), - NI_NUMERICHOST); - if (ret == 0) { - snprintf(output, sizeof(output), "%s#%s", hbuf, sbuf); - } else { - snprintf(output, sizeof(output), "(unknown)"); - PARA_WARNING_LOG("hostname lookup error (%s).\n", - gai_strerror(ret)); + if (getpeername(sockfd, (struct sockaddr *)&ss, &sslen) < 0) { + PARA_ERROR_LOG("can not determine remote address type: %s\n", + strerror(errno)); + } else if (!SS_IS_ADDR_V4MAPPED(&ss)) { + af_type = ss.ss_family; } - return output; + return generic_mtu(af_type) - estimated_header_overhead(af_type); } /** @@ -582,23 +621,38 @@ static char *host_and_port(const struct sockaddr_storage *ss) * remote side. * * \return A static character string identifying hostname and port of the - * chosen side. + * chosen side in numeric host:port format. * - * \sa getsockname(2), getpeername(2). + * \sa getsockname(2), getpeername(2), parse_url(), getnameinfo(3), + * services(5), nsswitch.conf(5). */ -static char *__get_sock_name(int fd, int (*getname)(int, struct sockaddr*, - socklen_t *)) +static char *__get_sock_name(int fd, typeof(getsockname) getname) { struct sockaddr_storage ss; + const struct sockaddr *sa; socklen_t sslen = sizeof(ss); + char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV]; + static char output[sizeof(hbuf) + sizeof(sbuf) + 4]; + int ret; if (getname(fd, (struct sockaddr *)&ss, &sslen) < 0) { - static char *dont_know = "(don't know)"; PARA_ERROR_LOG("can not determine address from fd %d: %s\n", fd, strerror(errno)); - return dont_know; + snprintf(output, sizeof(output), "(unknown)"); + return output; } - return host_and_port(&ss); + sa = normalize_ip_address(&ss); + ret = getnameinfo(sa, salen(sa), hbuf, sizeof(hbuf), sbuf, + sizeof(sbuf), NI_NUMERICHOST | NI_NUMERICSERV); + if (ret) { + PARA_WARNING_LOG("hostname lookup error (%s).\n", + gai_strerror(ret)); + snprintf(output, sizeof(output), "(lookup error)"); + } else if (sa->sa_family == AF_INET6) + snprintf(output, sizeof(output), "[%s]:%s", hbuf, sbuf); + else + snprintf(output, sizeof(output), "%s:%s", hbuf, sbuf); + return output; } /** @@ -633,72 +687,19 @@ char *remote_name(int sockfd) /** * Extract IPv4 or IPv6-mapped-IPv4 address from sockaddr_storage. - * \param ss Container of IPv4/6 address - * \return Extracted IPv4 address (different from 0) or 0 if unsuccessful. * - * \sa RFC 3493 + * \param ss Container of IPv4/6 address. + * \param ia Extracted IPv4 address (different from 0) or 0 if unsuccessful. + * + * \sa RFC 3493. */ -struct in_addr extract_v4_addr(const struct sockaddr_storage *ss) +void extract_v4_addr(const struct sockaddr_storage *ss, struct in_addr *ia) { - struct in_addr ia = {.s_addr = 0}; const struct sockaddr *sa = normalize_ip_address(ss); + memset(ia, 0, sizeof(*ia)); if (sa->sa_family == AF_INET) - ia = ((struct sockaddr_in *)sa)->sin_addr; - return ia; -} - -/** - * Send a binary buffer. - * - * \param fd The file descriptor. - * \param buf The buffer to be sent. - * \param len The length of \a buf. - * - * Send out the buffer and try to resend the remaining part in case of short - * writes. - * - * \return Standard. - */ -int send_bin_buffer(int fd, const char *buf, size_t len) -{ - if (!len) - PARA_CRIT_LOG("len == 0\n"); - return write_all(fd, buf, &len); -} - -/** - * Send a \p NULL-terminated buffer. - * - * \param fd The file descriptor. - * \param buf The null-terminated buffer to be send. - * - * This is equivalent to send_bin_buffer(fd, buf, strlen(buf)). - * - * \return Standard. - */ -int send_buffer(int fd, const char *buf) -{ - return send_bin_buffer(fd, buf, strlen(buf)); -} - -/** - * Send a buffer given by a format string. - * - * \param fd The file descriptor. - * \param fmt A format string. - * - * \return Standard. - */ -__printf_2_3 int send_va_buffer(int fd, const char *fmt, ...) -{ - char *msg; - int ret; - - PARA_VSPRINTF(fmt, msg); - ret = send_buffer(fd, msg); - free(msg); - return ret; + *ia = ((struct sockaddr_in *)sa)->sin_addr; } /** @@ -756,50 +757,68 @@ int recv_buffer(int fd, char *buf, size_t size) * Wrapper around the accept system call. * * \param fd The listening socket. + * \param rfds An optional fd_set pointer. * \param addr Structure which is filled in with the address of the peer socket. * \param size Should contain the size of the structure pointed to by \a addr. + * \param new_fd Result pointer. * - * Accept incoming connections on \a addr. Retry if interrupted. + * Accept incoming connections on \a addr, retry if interrupted. If \a rfds is + * not \p NULL, return 0 if \a fd is not set in \a rfds without calling accept(). * - * \return The new file descriptor on success, negative on errors. + * \return Negative on errors, zero if no connections are present to be accepted, + * one otherwise. * * \sa accept(2). */ -int para_accept(int fd, void *addr, socklen_t size) +int para_accept(int fd, fd_set *rfds, void *addr, socklen_t size, int *new_fd) { - int new_fd; + int ret; + if (rfds && !FD_ISSET(fd, rfds)) + return 0; do - new_fd = accept(fd, (struct sockaddr *) addr, &size); - while (new_fd < 0 && errno == EINTR); - return new_fd < 0? -ERRNO_TO_PARA_ERROR(errno) : new_fd; + ret = accept(fd, (struct sockaddr *) addr, &size); + while (ret < 0 && errno == EINTR); + + if (ret >= 0) { + *new_fd = ret; + return 1; + } + if (errno == EAGAIN || errno == EWOULDBLOCK) + return 0; + return -ERRNO_TO_PARA_ERROR(errno); } /** - * Probe the list of DCCP CCIDs supported locally by the host. - * \param ccids Array to be filled in. - * \param nccids Length of \a ccids. - * \return Pointer to \a ccids, NULL on failure. + * Probe the list of DCCP CCIDs configured on this host. + * \param ccid_array Pointer to return statically allocated array in. + * \return Number of elements returned in \a ccid_array or error. * * NB: This feature is only available on Linux > 2.6.30; on older kernels * ENOPROTOOPT ("Protocol not available") will be returned. */ -const uint8_t *dccp_available_ccids(uint8_t *ccids, uint8_t *nccids) +int dccp_available_ccids(uint8_t **ccid_array) { - int fd = makesock(IPPROTO_DCCP, 1, NULL, 0, NULL); + static uint8_t ccids[DCCP_MAX_HOST_CCIDS]; + socklen_t nccids = sizeof(ccids); + int ret, fd; - if (fd < 0) - return NULL; + ret = fd = makesock(IPPROTO_DCCP, 1, NULL, 0, NULL); + if (ret < 0) + return ret; if (getsockopt(fd, SOL_DCCP, DCCP_SOCKOPT_AVAILABLE_CCIDS, - ccids, (socklen_t *)nccids) < 0) { + ccids, &nccids) < 0) { + ret = errno; + close(fd); PARA_ERROR_LOG("No DCCP_SOCKOPT_AVAILABLE_CCIDS: %s\n", - strerror(errno)); - *nccids = 0; + strerror(ret)); + return -ERRNO_TO_PARA_ERROR(ret); } - close(fd); - return *nccids ? ccids : NULL; + close(fd); + *ccid_array = ccids; + return nccids; } /** @@ -873,15 +892,17 @@ err: * This function creates a local socket for sequenced, reliable, two-way, * connection-based byte streams. * - * \return The file descriptor, on success, negative on errors. + * \return The file descriptor of the connected socket on success, negative on + * errors. * * \sa create_local_socket(), unix(7), connect(2). */ -int create_remote_socket(const char *name) +int connect_local_socket(const char *name) { struct sockaddr_un unix_addr; int fd, ret; + PARA_DEBUG_LOG("connecting to %s\n", name); ret = init_unix_addr(&unix_addr, name); if (ret < 0) return ret; @@ -901,7 +922,7 @@ err: #ifndef HAVE_UCRED ssize_t send_cred_buffer(int sock, char *buf) { - return send_buffer(sock, buf); + return write_buffer(sock, buf); } int recv_cred_buffer(int fd, char *buf, size_t size) { @@ -1012,41 +1033,3 @@ int recv_cred_buffer(int fd, char *buf, size_t size) return result; } #endif /* HAVE_UCRED */ - -/** - * Receive a buffer and check for a pattern. - * - * \param fd The file descriptor to receive from. - * \param pattern The expected pattern. - * \param bufsize The size of the internal buffer. - * - * \return Positive if \a pattern was received, negative otherwise. - * - * This function tries to receive at most \a bufsize bytes from file descriptor - * \a fd. If at least \p strlen(\a pattern) bytes were received, the beginning - * of the received buffer is compared with \a pattern, ignoring case. - * - * \sa recv_buffer(), \sa strncasecmp(3). - */ -int recv_pattern(int fd, const char *pattern, size_t bufsize) -{ - size_t len = strlen(pattern); - char *buf = para_malloc(bufsize + 1); - int ret = -E_RECV_PATTERN, n = recv_buffer(fd, buf, bufsize + 1); - - if (n < len) - goto out; - if (strncasecmp(buf, pattern, len)) - goto out; - ret = 1; -out: - if (ret < 0) { - PARA_NOTICE_LOG("did not receive pattern '%s'\n", pattern); - if (n > 0) - PARA_NOTICE_LOG("recvd %d bytes: %s\n", n, buf); - else if (n < 0) - PARA_NOTICE_LOG("%s\n", para_strerror(-n)); - } - free(buf); - return ret; -}