X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=net.c;h=3f76d21c6cc9abf60ff5a98d1ac804f4b067ffef;hp=28d11d664c937404e034d65760c00e5fa8cc1a3a;hb=42f69f545fad18480d728bb6f25273976a0c01e0;hpb=c9a917fe5862bb042e36de84685b5c0fafa7f0eb;ds=inline diff --git a/net.c b/net.c index 28d11d66..3f76d21c 100644 --- a/net.c +++ b/net.c @@ -1,16 +1,8 @@ -/* - * Copyright (C) 2005-2013 Andre Noll - * - * Licensed under the GPL v2. For licencing details see COPYING. - */ +/* Copyright (C) 2005 Andre Noll , see file 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 +24,6 @@ #include -#include "para.h" #include "error.h" #include "net.h" #include "string.h" @@ -48,8 +39,8 @@ * \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. - * \sa RFC 4632 + * \return Pointer to \a addr if successful, NULL on error. + * \sa RFC 4632. */ char *parse_cidr(const char *cidr, char *addr, ssize_t addrlen, @@ -109,7 +100,7 @@ static bool is_v4_dot_quad(const char *address) * \param host The host string to check. * \return True if \a host passes the syntax checks. * - * \sa RFC 3986, 3.2.2; RFC 1123, 2.1; RFC 1034, 3.5 + * \sa RFC 3986, 3.2.2; RFC 1123, 2.1; RFC 1034, 3.5. */ static bool host_string_ok(const char *host) { @@ -151,7 +142,7 @@ static bool host_string_ok(const char *host) * \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 + * \sa RFC 3986, 3.2.2/3.2.3. */ char *parse_url(const char *url, char *host, ssize_t hostlen, @@ -180,8 +171,7 @@ char *parse_url(const char *url, } if (*o == ':') - if (para_atoi32(++o, port) < 0 || - *port < 0 || *port > 0xffff) + if (para_atoi32(++o, port) < 0 || *port < 0 || *port > 0xffff) goto failed; if (host_string_ok(host)) return host; @@ -192,11 +182,12 @@ failed: /** * Stringify port number, resolve into service name where defined. + * * \param port 2-byte port number, in host-byte-order. * \param transport Transport protocol name (e.g. "udp", "tcp"), or NULL. * \return Pointer to static result buffer. * - * \sa getservent(3), services(5), nsswitch.conf(5) + * \sa getservent(3), services(5), nsswitch.conf(5). */ const char *stringify_port(int port, const char *transport) { @@ -208,7 +199,7 @@ 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); } @@ -220,7 +211,7 @@ const char *stringify_port(int port, const char *transport) * * \param l4type The symbolic name of the transport-layer protocol. * - * \sa ip(7), socket(2) + * \sa ip(7), socket(2). */ static inline int sock_type(const unsigned l4type) { @@ -252,7 +243,7 @@ static const char *layer4_name(const unsigned l4type) * directly after makesock(). The 'pre_conn_opt' structure is for internal use * only and should not be visible elsewhere. * - * \sa setsockopt(2), makesock() + * \sa setsockopt(2), \ref makesock(). */ struct pre_conn_opt { int sock_level; /**< Second argument to setsockopt() */ @@ -293,7 +284,7 @@ struct flowopts *flowopt_new(void) * \param val The value to set \a opt to. * \param len Length of \a val. * - * \sa setsockopt(2) + * \sa setsockopt(2). */ void flowopt_add(struct flowopts *fo, int lev, int opt, const char *name, const void *val, int len) @@ -333,7 +324,14 @@ 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 +346,7 @@ 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 +364,7 @@ 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; @@ -374,7 +372,7 @@ static int lookup_address(unsigned l4type, bool passive, const char *host, struct addrinfo *addr = NULL, hints; *result = NULL; - sprintf(port, "%u", port_number & 0xffff); + sprintf(port, "%d", port_number & 0xffff); /* Set up address hint structure */ memset(&hints, 0, sizeof(hints)); hints.ai_family = AF_UNSPEC; @@ -402,7 +400,7 @@ 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. @@ -412,49 +410,46 @@ 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) { - int ret = -E_MAKESOCK, on = 1, sockfd = -1; + int ret = -E_MAKESOCK, on = 1; for (; ai; ai = ai->ai_next) { + int fd; ret = socket(ai->ai_family, sock_type(l4type), l4type); if (ret < 0) continue; - sockfd = ret; - flowopt_setopts(sockfd, fo); - if (passive) { - /* - * Reuse the address on passive sockets to avoid - * failure on restart (protocols using listen()) and - * when creating multiple listener instances (UDP - * multicast). - */ - if (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)); - return ret; - } - if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) { - close(sockfd); - continue; - } - return sockfd; - } else { - if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) == 0) - return sockfd; - close(sockfd); + 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 (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, + sizeof(on)) == -1) { + close(fd); + continue; + } + if (bind(fd, ai->ai_addr, ai->ai_addrlen) < 0) { + close(fd); + continue; + } + return fd; } return -E_MAKESOCK; } @@ -488,7 +483,6 @@ 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? @@ -507,7 +501,7 @@ int makesock(unsigned l4type, bool passive, const char *host, uint16_t port_numb * \return Positive integer (socket descriptor) on success, negative value * otherwise. * - * \sa makesock(), ip(7), ipv6(7), bind(2), listen(2). + * \sa \ref makesock(), ip(7), ipv6(7), bind(2), listen(2). */ int para_listen(unsigned l4type, uint16_t port, struct flowopts *fo) { @@ -553,7 +547,7 @@ static bool SS_IS_ADDR_V4MAPPED(const struct sockaddr_storage *ss) * \param ss Container of IPv4/6 address. * \return Pointer to normalized address (may be static storage). * - * \sa RFC 3493 + * \sa RFC 3493. */ static const struct sockaddr * normalize_ip_address(const struct sockaddr_storage *ss) @@ -598,14 +592,14 @@ 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. */ int generic_max_transport_msg_size(int sockfd) { - struct sockaddr_storage ss; + struct sockaddr_storage ss = {.ss_family = 0}; socklen_t sslen = sizeof(ss); int af_type = AF_INET; @@ -619,28 +613,26 @@ 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. * - * \sa getsockname(2), getpeername(2), parse_url(), getnameinfo(3), + * \sa getsockname(2), getpeername(2), \ref 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; + struct sockaddr_storage ss = {.ss_family = 0}; 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) { + 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)"); @@ -660,36 +652,6 @@ 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. * @@ -707,6 +669,32 @@ 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. * @@ -743,7 +731,7 @@ __must_check int recv_bin_buffer(int fd, char *buf, size_t size) * * \return The return value of the underlying call to \a recv_bin_buffer(). * - * \sa recv_bin_buffer() + * \sa \ref recv_bin_buffer() */ int recv_buffer(int fd, char *buf, size_t size) { @@ -826,63 +814,85 @@ int dccp_available_ccids(uint8_t **ccid_array) return nccids; } -/** - * Prepare a structure for \p AF_UNIX socket addresses. - * - * \param u Pointer to the struct to be prepared. - * \param name The socket pathname. +/* + * Prepare a structure for AF_UNIX socket addresses. * - * This just copies \a name to the sun_path component of \a u. + * This just copies name to the sun_path component of u, prepending a zero byte + * if abstract sockets are supported. * - * \return Positive on success, \p -E_NAME_TOO_LONG if \a name is longer - * than \p UNIX_PATH_MAX. + * The first call to this function tries to bind a socket to the abstract name + * space. The result of this test is stored in a static variable. Subsequent + * calls read this variable and create abstract sockets on systems that support + * them. */ static int init_unix_addr(struct sockaddr_un *u, const char *name) { - if (strlen(name) >= UNIX_PATH_MAX) + static int use_abstract; + + if (strlen(name) + 1 >= 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); + if (use_abstract == 0) { /* executed only once */ + int fd = socket(PF_UNIX, SOCK_STREAM, 0); + memcpy(u->sun_path, "\0x\0", 3); + if (bind(fd, (struct sockaddr *)u, sizeof(*u)) == 0) + use_abstract = 1; /* yes */ + else + use_abstract = -1; /* no */ + close(fd); + PARA_NOTICE_LOG("%susing abstract socket namespace\n", + use_abstract == 1? "" : "not "); + } + strcpy(u->sun_path + (use_abstract == 1? 1 : 0), 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. * - * This function creates a local socket for sequenced, reliable, - * two-way, connection-based byte streams. + * 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. * - * \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) { + struct sockaddr_un unix_addr; int fd, ret; - ret = init_unix_addr(unix_addr, name); + ret = init_unix_addr(&unix_addr, name); 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 (unix_addr.sun_path[0] != 0) { /* pathname socket */ + mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP + | S_IROTH | S_IWOTH; + 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); @@ -900,7 +910,7 @@ err: * \return The file descriptor of the connected socket on success, negative on * errors. * - * \sa create_local_socket(), unix(7), connect(2). + * \sa \ref create_local_socket(), unix(7), connect(2). */ int connect_local_socket(const char *name) { @@ -908,17 +918,15 @@ 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); + ret = init_unix_addr(&unix_addr, name); + if (ret < 0) goto err; - } - return fd; + if (connect(fd, (struct sockaddr *)&unix_addr, sizeof(unix_addr)) != -1) + return fd; + ret = -ERRNO_TO_PARA_ERROR(errno); err: close(fd); return ret; @@ -934,16 +942,17 @@ 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). */ ssize_t send_cred_buffer(int sock, char *buf) { @@ -956,7 +965,7 @@ 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(); @@ -974,7 +983,7 @@ 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; } @@ -990,17 +999,17 @@ 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; @@ -1029,7 +1038,7 @@ 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)); }