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Diffstat (limited to '')
| -rw-r--r-- | src/lib/socket.c | 394 |
1 files changed, 394 insertions, 0 deletions
diff --git a/src/lib/socket.c b/src/lib/socket.c new file mode 100644 index 0000000..3c88b78 --- /dev/null +++ b/src/lib/socket.c @@ -0,0 +1,394 @@ +/* + * This program is is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA + */ + +/** + * $Id$ + * @file socket.c + * @brief Functions for establishing and managing low level sockets. + * + * @author Arran Cudbard-Bell <a.cudbardb@freeradius.org> + * @author Alan DeKok <aland@freeradius.org> + * + * @copyright 2015 The FreeRADIUS project + */ + #include <freeradius-devel/libradius.h> + +#ifdef HAVE_SYS_UN_H +# include <sys/un.h> +# ifndef SUN_LEN +# define SUN_LEN(su) (sizeof(*(su)) - sizeof((su)->sun_path) + strlen((su)->sun_path)) +# endif + +/** Open a Unix socket + * + * @note If the file doesn't exist then errno will be set to ENOENT. + * + * The following code demonstrates using this function with a connection timeout: + @code {.c} + sockfd = fr_socket_client_unix(path, true); + if (sockfd < 0) { + fr_perror(); + exit(1); +} + if ((errno == EINPROGRESS) && (fr_socket_wait_for_connect(sockfd, timeout) < 0)) { + error: + fr_perror(); + close(sockfd); + goto error; +} +//Optionally, if blocking operation is required + if (fr_blocking(sockfd) < 0) goto error; + @endcode + * + * @param path to the file bound to the unix socket. + * @param async Whether to set the socket to nonblocking, allowing use of + * #fr_socket_wait_for_connect. + * @return socket FD on success, -1 on error. + */ +int fr_socket_client_unix(char const *path, bool async) +{ + int sockfd = -1; + size_t len; + socklen_t socklen; + struct sockaddr_un saremote; + + len = strlen(path); + if (len >= sizeof(saremote.sun_path)) { + fr_strerror_printf("Path too long, maximum length is %zu", sizeof(saremote.sun_path) - 1); + errno = EINVAL; + return -1; + } + + sockfd = socket(AF_UNIX, SOCK_STREAM, 0); + if (sockfd < 0) { + fr_strerror_printf("Failed creating UNIX socket: %s", fr_syserror(errno)); + return -1; + } + + if (async && (fr_nonblock(sockfd) < 0)) { + close(sockfd); + return -1; + } + + saremote.sun_family = AF_UNIX; + memcpy(saremote.sun_path, path, len + 1); /* SUN_LEN does strlen */ + + socklen = SUN_LEN(&saremote); + + /* + * Although we ignore SIGPIPE, some operating systems + * like BSD and OSX ignore the ignoring. + * + * Fortunately, those operating systems usually support + * SO_NOSIGPIPE, to prevent them raising the signal in + * the first place. + */ +#ifdef SO_NOSIGPIPE + { + int set = 1; + + setsockopt(sockfd, SOL_SOCKET, SO_NOSIGPIPE, (void *)&set, sizeof(int)); + } +#endif + + if (connect(sockfd, (struct sockaddr *)&saremote, socklen) < 0) { + /* + * POSIX says the only time we will get this, + * is if the socket has been marked as + * nonblocking. This is not an error, the caller + * must check the state of errno, and wait for + * the connection to complete. + */ + if (errno == EINPROGRESS) return sockfd; + + close(sockfd); + fr_strerror_printf("Failed connecting to %s: %s", path, fr_syserror(errno)); + + return -1; + } + return sockfd; +} +#else +int fr_socket_client_unix(UNUSED char const *path, UNUSED bool async) +{ + fprintf(stderr, "Unix domain sockets not supported on this system"); + return -1; +} +#endif /* WITH_SYS_UN_H */ + +/** Establish a connected TCP socket + * + * The following code demonstrates using this function with a connection timeout: + @code {.c} + sockfd = fr_socket_client_tcp(NULL, ipaddr, port, true); + if (sockfd < 0) { + fr_perror(); + exit(1); +} + if ((errno == EINPROGRESS) && (fr_socket_wait_for_connect(sockfd, timeout) < 0)) { + error: + fr_perror(); + close(sockfd); + goto error; +} +//Optionally, if blocking operation is required + if (fr_blocking(sockfd) < 0) goto error; + @endcode + * + * @param src_ipaddr to bind socket to, may be NULL if socket is not bound to any specific + * address. + * @param dst_ipaddr Where to connect to. + * @param dst_port Where to connect to. + * @param async Whether to set the socket to nonblocking, allowing use of + * #fr_socket_wait_for_connect. + * @return FD on success, -1 on failure. + */ +int fr_socket_client_tcp(fr_ipaddr_t *src_ipaddr, fr_ipaddr_t *dst_ipaddr, uint16_t dst_port, bool async) +{ + int sockfd; + struct sockaddr_storage salocal; + socklen_t salen; + + if (!dst_ipaddr) return -1; + + sockfd = socket(dst_ipaddr->af, SOCK_STREAM, 0); + if (sockfd < 0) { + fr_strerror_printf("Error creating TCP socket: %s", fr_syserror(errno)); + return sockfd; + } + + if (async && (fr_nonblock(sockfd) < 0)) { + close(sockfd); + return -1; + } + + /* + * Allow the caller to bind us to a specific source IP. + */ + if (src_ipaddr && (src_ipaddr->af != AF_UNSPEC)) { + if (!fr_ipaddr2sockaddr(src_ipaddr, 0, &salocal, &salen)) { + close(sockfd); + return -1; + } + + if (bind(sockfd, (struct sockaddr *) &salocal, salen) < 0) { + fr_strerror_printf("Failure binding to IP: %s", fr_syserror(errno)); + close(sockfd); + return -1; + } + } + + if (!fr_ipaddr2sockaddr(dst_ipaddr, dst_port, &salocal, &salen)) { + close(sockfd); + return -1; + } + + /* + * Although we ignore SIGPIPE, some operating systems + * like BSD and OSX ignore the ignoring. + * + * Fortunately, those operating systems usually support + * SO_NOSIGPIPE, to prevent them raising the signal in + * the first place. + */ +#ifdef SO_NOSIGPIPE + { + int set = 1; + + setsockopt(sockfd, SOL_SOCKET, SO_NOSIGPIPE, (void *)&set, sizeof(int)); + } +#endif + + if (connect(sockfd, (struct sockaddr *) &salocal, salen) < 0) { + /* + * POSIX says the only time we will get this, + * is if the socket has been marked as + * nonblocking. This is not an error, the caller + * must check the state of errno, and wait for + * the connection to complete. + */ + if (errno == EINPROGRESS) return sockfd; + + fr_strerror_printf("Failed connecting socket: %s", fr_syserror(errno)); + close(sockfd); + return -1; + } + + return sockfd; +} + +/** Establish a connected UDP socket + * + * Connected UDP sockets can be used with write(), unlike unconnected sockets + * which must be used with sendto and recvfrom. + * + * The following code demonstrates using this function with a connection timeout: + @code {.c} + sockfd = fr_socket_client_udp(NULL, ipaddr, port, true); + if (sockfd < 0) { + fr_perror(); + exit(1); +} + if ((errno == EINPROGRESS) && (fr_socket_wait_for_connect(sockfd, timeout) < 0)) { + error: + fr_perror(); + close(sockfd); + goto error; +} +//Optionally, if blocking operation is required + if (fr_blocking(sockfd) < 0) goto error; + @endcode + * + * @param src_ipaddr to bind socket to, may be NULL if socket is not bound to any specific + * address. + * @param dst_ipaddr Where to send datagrams. + * @param dst_port Where to send datagrams. + * @param async Whether to set the socket to nonblocking, allowing use of + * #fr_socket_wait_for_connect. + * @return FD on success, -1 on failure. + */ +int fr_socket_client_udp(fr_ipaddr_t *src_ipaddr, fr_ipaddr_t *dst_ipaddr, uint16_t dst_port, bool async) +{ + int sockfd; + struct sockaddr_storage salocal; + socklen_t salen; + + if (!dst_ipaddr) return -1; + + sockfd = socket(dst_ipaddr->af, SOCK_DGRAM, 0); + if (sockfd < 0) { + fr_strerror_printf("Error creating UDP socket: %s", fr_syserror(errno)); + return sockfd; + } + + if (async && (fr_nonblock(sockfd) < 0)) { + close(sockfd); + return -1; + } + + /* + * Allow the caller to bind us to a specific source IP. + */ + if (src_ipaddr && (src_ipaddr->af != AF_UNSPEC)) { + if (!fr_ipaddr2sockaddr(src_ipaddr, 0, &salocal, &salen)) { + close(sockfd); + return -1; + } + + if (bind(sockfd, (struct sockaddr *) &salocal, salen) < 0) { + fr_strerror_printf("Failure binding to IP: %s", fr_syserror(errno)); + close(sockfd); + return -1; + } + } + + if (!fr_ipaddr2sockaddr(dst_ipaddr, dst_port, &salocal, &salen)) { + close(sockfd); + return -1; + } + + /* + * Although we ignore SIGPIPE, some operating systems + * like BSD and OSX ignore the ignoring. + * + * Fortunately, those operating systems usually support + * SO_NOSIGPIPE, to prevent them raising the signal in + * the first place. + */ +#ifdef SO_NOSIGPIPE + { + int set = 1; + + setsockopt(sockfd, SOL_SOCKET, SO_NOSIGPIPE, (void *)&set, sizeof(int)); + } +#endif + + if (connect(sockfd, (struct sockaddr *) &salocal, salen) < 0) { + /* + * POSIX says the only time we will get this, + * is if the socket has been marked as + * nonblocking. This is not an error, the caller + * must check the state of errno, and wait for + * the connection to complete. + */ + if (errno == EINPROGRESS) return sockfd; + + fr_strerror_printf("Failed connecting socket: %s", fr_syserror(errno)); + close(sockfd); + return -1; + } + + return sockfd; +} + +/** Wait for a socket to be connected, with an optional timeout + * + * @note On error the caller is expected to ``close(sockfd)``. + * + * @param sockfd the socket to wait on. + * @param timeout How long to wait for socket to open. + * @return 0 on success, -1 on connection error, -2 on timeout, -3 on select error. + */ +int fr_socket_wait_for_connect(int sockfd, struct timeval *timeout) +{ + int ret; + fd_set error_set; + fd_set write_set; /* POSIX says sockets are open when they become writeable */ + + FD_ZERO(&error_set); + FD_ZERO(&write_set); + + FD_SET(sockfd, &error_set); + FD_SET(sockfd, &write_set); + + /* Don't let signals mess up the select */ + do { + ret = select(sockfd + 1, NULL, &write_set, &error_set, timeout); + } while ((ret == -1) && (errno == EINTR)); + + switch (ret) { + case 1: /* ok (maybe) */ + { + int error; + socklen_t socklen = sizeof(error); + + if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, (void *)&error, &socklen)) { + fr_strerror_printf("Failed connecting socket: %s", fr_syserror(errno)); + return -1; + } + + if (FD_ISSET(sockfd, &error_set)) { + fr_strerror_printf("Failed connecting socket: Unknown error"); + return -1; + } + } + return 0; + + case 0: /* timeout */ + if (!fr_assert(timeout)) return -1; + fr_strerror_printf("Connection timed out after %" PRIu64"ms", + (timeout->tv_sec * (uint64_t)1000) + (timeout->tv_usec / 1000)); + return -2; + + case -1: /* select error */ + fr_strerror_printf("Failed waiting for connection: %s", fr_syserror(errno)); + return -3; + + default: + fr_assert(0); + return -1; + } +} |