X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=net.c;h=4a31f013446877e45c780e7eb24a27a0a1042c3a;hp=b9729b6988f894a3e346a591b477ed0fb9012149;hb=081c8921f827c1ed482c45ba22bd8bb97db2838b;hpb=eecc102ad0abeb0335fe994bb72031a15b9090d7 diff --git a/net.c b/net.c index b9729b69..4a31f013 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" @@ -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)); @@ -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) { @@ -380,8 +375,8 @@ int makesock(unsigned l4type, bool passive, const char *host, uint16_t port_number, struct flowopts *fo) { - struct addrinfo *local = NULL, *src, - *remote = NULL, *dst, hints; + struct addrinfo *local = NULL, *src = NULL, *remote = NULL, + *dst = NULL, hints; unsigned int l3type = AF_UNSPEC; int rc, on = 1, sockfd = -1, socktype = sock_type(l4type); @@ -414,7 +409,8 @@ int makesock(unsigned l4type, bool passive, layer4_name(l4type), host? host : (passive? "[loopback]" : "[localhost]"), port, gai_strerror(rc)); - return -E_ADDRESS_LOOKUP; + rc = -E_ADDRESS_LOOKUP; + goto out; } /* Iterate over all src/dst combination, exhausting dst first */ @@ -436,9 +432,11 @@ 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); @@ -461,6 +459,7 @@ get_next_src: if (src && (src = src->ai_next)) /* restart inner loop */ dst = remote; } +out: if (local) freeaddrinfo(local); if (remote) @@ -468,11 +467,12 @@ get_next_src: flowopt_cleanup(fo); if (src == NULL && dst == NULL) { - rc = errno; + if (rc >= 0) + rc = -E_MAKESOCK; PARA_ERROR_LOG("can not create %s socket %s#%s.\n", layer4_name(l4type), host? host : (passive? "[loopback]" : "[localhost]"), port); - return -ERRNO_TO_PARA_ERROR(rc); + return rc; } return sockfd; } @@ -520,6 +520,14 @@ 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. @@ -530,11 +538,10 @@ 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; @@ -546,31 +553,49 @@ 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); } /** @@ -581,23 +606,38 @@ 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; } /** @@ -632,72 +672,19 @@ 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; } /** @@ -755,50 +742,68 @@ 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; } /** @@ -872,15 +877,17 @@ 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; @@ -900,7 +907,7 @@ 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) { @@ -1011,41 +1018,3 @@ 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; -}