X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=net.c;h=1b142a3cd4a25b87fe2e31c86caaf32e4be5f51e;hp=205041fdaec3881c4196d3d7bada084036fea3bf;hb=a13a1e0d202a8969374b9a70562556e689597f2d;hpb=63a8840ff755de24d7a205f7ccc07ad0c68dc844 diff --git a/net.c b/net.c index 205041fd..1b142a3c 100644 --- a/net.c +++ b/net.c @@ -1,16 +1,12 @@ /* - * Copyright (C) 2005-2013 Andre Noll + * Copyright (C) 2005 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ /** \file net.c Networking-related helper functions. */ -/* - * Since glibc 2.8, the _GNU_SOURCE feature test macro must be defined in order - * to obtain the definition of the ucred structure. - */ -#define _GNU_SOURCE +#include "para.h" #include #include @@ -32,7 +28,6 @@ #include -#include "para.h" #include "error.h" #include "net.h" #include "string.h" @@ -48,7 +43,7 @@ * \param netmask Value of the netmask part in \a cidr or the * default of 32 if not specified. * - * \return Pointer to \a addr if succesful, NULL on error. + * \return Pointer to \a addr if successful, NULL on error. * \sa RFC 4632 */ char *parse_cidr(const char *cidr, @@ -208,7 +203,7 @@ const char *stringify_port(int port, const char *transport) struct servent *se = getservbyport(htons(port), transport); if (se == NULL) - snprintf(service, sizeof(service), "%u", port); + snprintf(service, sizeof(service), "%d", port); else snprintf(service, sizeof(service), "%s", se->s_name); } @@ -333,7 +328,14 @@ static void flowopt_setopts(int sockfd, struct flowopts *fo) } } -static void flowopt_cleanup(struct flowopts *fo) +/** + * Deallocate all resources of a flowopts structure. + * + * \param fo A pointer as returned from flowopt_new(). + * + * It's OK to pass \p NULL here in which case the function does nothing. + */ +void flowopt_cleanup(struct flowopts *fo) { struct pre_conn_opt *cur, *next; @@ -348,7 +350,7 @@ static void flowopt_cleanup(struct flowopts *fo) free(fo); } -/* +/** * Resolve an IPv4/IPv6 address. * * \param l4type The layer-4 type (\p IPPROTO_xxx). @@ -366,7 +368,7 @@ static void flowopt_cleanup(struct flowopts *fo) * * \sa getaddrinfo(3). */ -static int lookup_address(unsigned l4type, bool passive, const char *host, +int lookup_address(unsigned l4type, bool passive, const char *host, int port_number, struct addrinfo **result) { int ret; @@ -402,7 +404,7 @@ static int lookup_address(unsigned l4type, bool passive, const char *host, return 1; } -/* +/** * Create an active or passive socket. * * \param l4type \p IPPROTO_TCP, \p IPPROTO_UDP, or \p IPPROTO_DCCP. @@ -412,71 +414,48 @@ static int lookup_address(unsigned l4type, bool passive, const char *host, * * 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. + * fo is supplied, options are set but cleanup must be performed in the caller. * * \return File descriptor on success, \p E_MAKESOCK on errors. * * \sa \ref lookup_address(), \ref makesock(), ip(7), ipv6(7), bind(2), * connect(2). */ -static int makesock_addrinfo(unsigned l4type, bool passive, struct addrinfo *ai, +int makesock_addrinfo(unsigned l4type, bool passive, struct addrinfo *ai, struct flowopts *fo) { - struct addrinfo *local, *remote, *src, *dst; - int ret = -E_MAKESOCK, on = 1, sockfd = -1; + int ret = -E_MAKESOCK, on = 1; - if (passive) { - local = ai; - remote = NULL; - } else { - local = NULL; - remote = ai; - } - - /* Iterate over all src/dst combination, exhausting dst first */ - for (src = local, dst = remote; src != NULL || dst != NULL; /* no op */ ) { - ret = socket(src ? src->ai_family : dst->ai_family, - sock_type(l4type), l4type); + for (; ai; ai = ai->ai_next) { + int fd; + ret = socket(ai->ai_family, sock_type(l4type), l4type); if (ret < 0) - goto get_next_dst; - sockfd = ret; + continue; + fd = ret; + flowopt_setopts(fd, fo); + if (!passive) { + if (connect(fd, ai->ai_addr, ai->ai_addrlen) == 0) + return fd; + close(fd); + continue; + } /* * Reuse the address on passive sockets to avoid failure on * restart (protocols using listen()) and when creating * multiple listener instances (UDP multicast). */ - if (passive && setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, - &on, sizeof(on)) == -1) { - ret = -ERRNO_TO_PARA_ERROR(errno); - close(sockfd); - PARA_ERROR_LOG("can not set SO_REUSEADDR: %s\n", - para_strerror(-ret)); - break; - } - flowopt_setopts(sockfd, fo); - - if (src) { - if (bind(sockfd, src->ai_addr, src->ai_addrlen) < 0) { - close(sockfd); - goto get_next_src; - } - /* bind completed successfully */ - break; + if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, + sizeof(on)) == -1) { + close(fd); + continue; } - - if (dst && connect(sockfd, dst->ai_addr, dst->ai_addrlen) == 0) - break; /* connection completed successfully */ - close(sockfd); -get_next_dst: - if (dst && (dst = dst->ai_next)) + if (bind(fd, ai->ai_addr, ai->ai_addrlen) < 0) { + close(fd); continue; -get_next_src: - if (src && (src = src->ai_next)) /* restart inner loop */ - dst = remote; + } + return fd; } - if (src == NULL && dst == NULL) - return ret < 0? ret : -E_MAKESOCK; - return sockfd; + return -E_MAKESOCK; } /** @@ -508,7 +487,6 @@ int makesock(unsigned l4type, bool passive, const char *host, uint16_t port_numb ret = makesock_addrinfo(l4type, passive, ai, fo); if (ai) freeaddrinfo(ai); - flowopt_cleanup(fo); if (ret < 0) { PARA_ERROR_LOG("can not create %s socket %s#%d.\n", layer4_name(l4type), host? host : (passive? @@ -618,7 +596,7 @@ static inline int estimated_header_overhead(const int af_type) * * \param sockfd The socket file descriptor. * - * The socket must be connected. See RFC 1122, 3.3.3. If the protocol familiy + * The socket must be connected. See RFC 1122, 3.3.3. If the protocol family * could not be determined, \p AF_INET is assumed. * * \return The maximum message size of the address family type. @@ -639,11 +617,9 @@ int generic_max_transport_msg_size(int sockfd) } /** - * Look up the local or remote side of a connected socket structure. + * Look up the remote side of a connected socket structure. * * \param fd The socket descriptor of the connected socket. - * \param getname Either \p getsockname() for local, or \p getpeername() for - * remote side. * * \return A static character string identifying hostname and port of the * chosen side in numeric host:port format. @@ -651,7 +627,7 @@ int generic_max_transport_msg_size(int sockfd) * \sa getsockname(2), getpeername(2), parse_url(), getnameinfo(3), * services(5), nsswitch.conf(5). */ -static char *__get_sock_name(int fd, typeof(getsockname) getname) +char *remote_name(int fd) { struct sockaddr_storage ss; const struct sockaddr *sa; @@ -660,7 +636,7 @@ static char *__get_sock_name(int fd, typeof(getsockname) getname) static char output[sizeof(hbuf) + sizeof(sbuf) + 4]; int ret; - if (getname(fd, (struct sockaddr *)&ss, &sslen) < 0) { + if (getpeername(fd, (struct sockaddr *)&ss, &sslen) < 0) { PARA_ERROR_LOG("can not determine address from fd %d: %s\n", fd, strerror(errno)); snprintf(output, sizeof(output), "(unknown)"); @@ -680,36 +656,6 @@ static char *__get_sock_name(int fd, typeof(getsockname) getname) return output; } -/** - * Look up the local side of a connected socket structure. - * - * \param sockfd The file descriptor of the socket. - * - * \return A pointer to a static buffer containing hostname an port. This - * buffer must not be freed by the caller. - * - * \sa remote_name(). - */ -char *local_name(int sockfd) -{ - return __get_sock_name(sockfd, getsockname); -} - -/** - * Look up the remote side of a connected socket structure. - * - * \param sockfd The file descriptor of the socket. - * - * \return Analogous to the return value of \ref local_name() but for the - * remote side. - * - * \sa local_name(). - */ -char *remote_name(int sockfd) -{ - return __get_sock_name(sockfd, getpeername); -} - /** * Extract IPv4 or IPv6-mapped-IPv4 address from sockaddr_storage. * @@ -727,6 +673,32 @@ void extract_v4_addr(const struct sockaddr_storage *ss, struct in_addr *ia) *ia = ((struct sockaddr_in *)sa)->sin_addr; } +/** + * Compare the address part of IPv4/6 addresses. + * + * \param sa1 First address. + * \param sa2 Second address. + * + * \return True iff the IP address of \a sa1 and \a sa2 match. + */ +bool sockaddr_equal(const struct sockaddr *sa1, const struct sockaddr *sa2) +{ + if (!sa1 || !sa2) + return false; + if (sa1->sa_family != sa2->sa_family) + return false; + if (sa1->sa_family == AF_INET) { + struct sockaddr_in *a1 = (typeof(a1))sa1, + *a2 = (typeof (a2))sa2; + return a1->sin_addr.s_addr == a2->sin_addr.s_addr; + } else if (sa1->sa_family == AF_INET6) { + struct sockaddr_in6 *a1 = (typeof(a1))sa1, + *a2 = (typeof (a2))sa2; + return !memcmp(a1, a2, sizeof(*a1)); + } else + return false; +} + /** * Receive data from a file descriptor. * @@ -857,52 +829,66 @@ int dccp_available_ccids(uint8_t **ccid_array) * \return Positive on success, \p -E_NAME_TOO_LONG if \a name is longer * than \p UNIX_PATH_MAX. */ -static int init_unix_addr(struct sockaddr_un *u, const char *name) +static int init_unix_addr(struct sockaddr_un *u, const char *name, + bool abstract) { - if (strlen(name) >= UNIX_PATH_MAX) + if (strlen(name) + abstract >= UNIX_PATH_MAX) return -E_NAME_TOO_LONG; memset(u->sun_path, 0, UNIX_PATH_MAX); u->sun_family = PF_UNIX; - strcpy(u->sun_path, name); + strcpy(u->sun_path + abstract, name); return 1; } /** - * Prepare, create, and bind a socket for local communication. + * Create a socket for local communication and listen on it. * * \param name The socket pathname. - * \param unix_addr Pointer to the \p AF_UNIX socket structure. - * \param mode The desired mode of the socket. + * \param mode The desired permissions of the socket. + * + * This function creates a passive local socket for sequenced, reliable, + * two-way, connection-based byte streams. The socket file descriptor is set to + * nonblocking mode and listen(2) is called to prepare the socket for + * accepting incoming connection requests. * - * This function creates a local socket for sequenced, reliable, - * two-way, connection-based byte streams. + * If mode is zero, an abstract socket (a non-portable Linux extension) is + * created. In this case the socket name has no connection with filesystem + * pathnames. * - * \return The file descriptor, on success, negative on errors. + * \return The file descriptor on success, negative error code on failure. * - * \sa socket(2) - * \sa bind(2) - * \sa chmod(2) + * \sa socket(2), \sa bind(2), \sa chmod(2), listen(2), unix(7). */ -int create_local_socket(const char *name, struct sockaddr_un *unix_addr, - mode_t mode) +int create_local_socket(const char *name, mode_t mode) { + struct sockaddr_un unix_addr; int fd, ret; + bool abstract = mode == 0; - ret = init_unix_addr(unix_addr, name); + ret = init_unix_addr(&unix_addr, name, abstract); if (ret < 0) return ret; ret = socket(PF_UNIX, SOCK_STREAM, 0); if (ret < 0) return -ERRNO_TO_PARA_ERROR(errno); fd = ret; - ret = bind(fd, (struct sockaddr *) unix_addr, UNIX_PATH_MAX); + ret = mark_fd_nonblocking(fd); + if (ret < 0) + goto err; + ret = bind(fd, (struct sockaddr *)&unix_addr, sizeof(unix_addr)); if (ret < 0) { ret = -ERRNO_TO_PARA_ERROR(errno); goto err; } - ret = -E_CHMOD; - if (chmod(name, mode) < 0) + if (!abstract) { + ret = -E_CHMOD; + if (chmod(name, mode) < 0) + goto err; + } + if (listen(fd , 5) < 0) { + ret = -ERRNO_TO_PARA_ERROR(errno); goto err; + } return fd; err: close(fd); @@ -928,17 +914,22 @@ int connect_local_socket(const char *name) int fd, ret; PARA_DEBUG_LOG("connecting to %s\n", name); - ret = init_unix_addr(&unix_addr, name); - if (ret < 0) - return ret; fd = socket(PF_UNIX, SOCK_STREAM, 0); if (fd < 0) return -ERRNO_TO_PARA_ERROR(errno); - if (connect(fd, (struct sockaddr *)&unix_addr, sizeof(unix_addr)) == -1) { - ret = -ERRNO_TO_PARA_ERROR(errno); + /* first try (linux-only) abstract socket */ + ret = init_unix_addr(&unix_addr, name, true); + if (ret < 0) goto err; - } - return fd; + if (connect(fd, (struct sockaddr *)&unix_addr, sizeof(unix_addr)) != -1) + return fd; + /* next try pathname socket */ + ret = init_unix_addr(&unix_addr, name, false); + if (ret < 0) + goto err; + if (connect(fd, (struct sockaddr *)&unix_addr, sizeof(unix_addr)) != -1) + return fd; + ret = -ERRNO_TO_PARA_ERROR(errno); err: close(fd); return ret; @@ -954,16 +945,18 @@ int recv_cred_buffer(int fd, char *buf, size_t size) return recv_buffer(fd, buf, size) > 0? 1 : -E_RECVMSG; } #else /* HAVE_UCRED */ + /** - * Send \p NULL-terminated buffer and Unix credentials of the current process. + * Send a buffer and the credentials of the current process to a socket. * - * \param sock The socket file descriptor. - * \param buf The buffer to be sent. + * \param sock The file descriptor of the sending socket. + * \param buf The zero-terminated buffer to send. * - * \return On success, this call returns the number of characters sent. On - * error, \p -E_SENDMSG is returned. + * \return On success, this call returns the number of bytes sent. On errors, + * \p -E_SENDMSG is returned. * - * \sa sendmsg(2), okir's Black Hats Manual. + * \sa \ref recv_cred_buffer, sendmsg(2), socket(7), unix(7), okir's Black Hats + * Manual. */ ssize_t send_cred_buffer(int sock, char *buf) { @@ -976,7 +969,7 @@ ssize_t send_cred_buffer(int sock, char *buf) /* Response data */ iov.iov_base = buf; - iov.iov_len = strlen(buf); + iov.iov_len = strlen(buf); c.pid = getpid(); c.uid = getuid(); c.gid = getgid(); @@ -994,7 +987,7 @@ ssize_t send_cred_buffer(int sock, char *buf) *(struct ucred *)CMSG_DATA(cmsg) = c; msg.msg_controllen = cmsg->cmsg_len; ret = sendmsg(sock, &msg, 0); - if (ret < 0) + if (ret < 0) ret = -E_SENDMSG; return ret; } @@ -1010,17 +1003,17 @@ static void dispose_fds(int *fds, unsigned num) /** * Receive a buffer and the Unix credentials of the sending process. * - * \param fd the socket file descriptor. - * \param buf the buffer to store the message. - * \param size the size of \a buffer. + * \param fd The file descriptor of the receiving socket. + * \param buf The buffer to store the received message. + * \param size The length of \a buf in bytes. * - * \return negative on errors, the user id on success. + * \return Negative on errors, the user id of the sending process on success. * - * \sa recvmsg(2), okir's Black Hats Manual. + * \sa \ref send_cred_buffer and the references given there. */ int recv_cred_buffer(int fd, char *buf, size_t size) { - char control[255]; + char control[255] __a_aligned(8); struct msghdr msg; struct cmsghdr *cmsg; struct iovec iov; @@ -1049,7 +1042,7 @@ int recv_cred_buffer(int fd, char *buf, size_t size) } else if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { - dispose_fds((int *) CMSG_DATA(cmsg), + dispose_fds((int *)CMSG_DATA(cmsg), (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int)); }