X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=net.c;h=eaa1cfb81146b3dc4fd7bb11cd41df447dc0e825;hp=986660fa8f12fd11649d9bd4b3310b01837811dc;hb=refs%2Fheads%2Fmaint;hpb=bb4e94595a1e57e66deacd4efc3512d947f16f19 diff --git a/net.c b/net.c index 986660fa..91200fc0 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 @@ -18,21 +10,8 @@ #include #include #include - -/* At least NetBSD needs these. */ -#ifndef AI_V4MAPPED -#define AI_V4MAPPED 0 -#endif -#ifndef AI_ALL -#define AI_ALL 0 -#endif -#ifndef AI_ADDRCONFIG -#define AI_ADDRCONFIG 0 -#endif - #include -#include "para.h" #include "error.h" #include "net.h" #include "string.h" @@ -48,8 +27,8 @@ * \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 +88,7 @@ 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 +130,7 @@ 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 +159,7 @@ 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; @@ -190,13 +168,44 @@ failed: return NULL; } +/** + * Pretty-print a host/port pair. + * + * \param url NULL, or any string accepted by \ref parse_url(). + * \param default_port Applies if url has no port. + * + * If the url argument is NULL, the function returns the string + * 0.0.0.0:default_port. Otherwise it calls \ref parse_url() to check the + * syntax of the input string given by url. On errors the string "?" is + * returned. Otherwise, if url contains a port, a copy of url is returned. If + * no port was supplied, a colon and the default port are appended to url. + * + * \return In all cases the returned string is a allocated with malloc(3) and + * has to be freed by the caller. + */ +char *format_url(const char *url, int default_port) +{ + char host[MAX_HOSTLEN]; + int url_port; + + if (!url) + return make_message("0.0.0.0:%d", default_port); + if (!parse_url(url, host, sizeof(host), &url_port)) + return make_message("?"); + if (url_port < 0) + return make_message("%s:%d", url, default_port); + else + return para_strdup(url); +} + /** * 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 +217,7 @@ 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 +229,7 @@ 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 +261,7 @@ 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 +302,7 @@ 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) @@ -381,7 +390,7 @@ 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; @@ -434,15 +443,20 @@ int makesock_addrinfo(unsigned l4type, bool passive, struct addrinfo *ai, for (; ai; ai = ai->ai_next) { int fd; ret = socket(ai->ai_family, sock_type(l4type), l4type); - if (ret < 0) + if (ret < 0) { + PARA_NOTICE_LOG("socket(): %s\n", strerror(errno)); continue; + } fd = ret; flowopt_setopts(fd, fo); if (!passive) { - if (connect(fd, ai->ai_addr, ai->ai_addrlen) == 0) - return fd; - close(fd); - continue; + if (connect(fd, ai->ai_addr, ai->ai_addrlen) < 0) { + PARA_NOTICE_LOG("connect(): %s\n", + strerror(errno)); + close(fd); + continue; + } + return fd; } /* * Reuse the address on passive sockets to avoid failure on @@ -451,10 +465,12 @@ int makesock_addrinfo(unsigned l4type, bool passive, struct addrinfo *ai, */ if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) { + PARA_NOTICE_LOG("setsockopt(): %s\n", strerror(errno)); close(fd); continue; } if (bind(fd, ai->ai_addr, ai->ai_addrlen) < 0) { + PARA_NOTICE_LOG("bind(): %s\n", strerror(errno)); close(fd); continue; } @@ -504,18 +520,28 @@ int makesock(unsigned l4type, bool passive, const char *host, uint16_t port_numb * Create a passive / listening socket. * * \param l4type The transport-layer type (\p IPPROTO_xxx). - * \param port The decimal port number to listen on. - * \param fo Flowopts (if any) to set before starting to listen. + * \param addr Passed to \ref parse_url() if not NULL. + * \param port Ignored if addr contains a port number. * * \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) +int para_listen(unsigned l4type, const char *addr, uint16_t port) { - int ret, fd = makesock(l4type, 1, NULL, port, fo); - + char host[MAX_HOSTLEN]; + int ret, fd, addr_port; + + if (addr) { + if (!parse_url(addr, host, sizeof(host), &addr_port)) + return -ERRNO_TO_PARA_ERROR(EINVAL); + if (addr_port > 0) + port = addr_port; + addr = host; + } + fd = makesock(l4type, true /* passive */, addr, port, + NULL /* no flowopts */); if (fd > 0) { ret = listen(fd, BACKLOG); if (ret < 0) { @@ -529,6 +555,22 @@ int para_listen(unsigned l4type, uint16_t port, struct flowopts *fo) return fd; } +/** + * Create a socket which listens on all network addresses. + * + * \param l4type See \ref para_listen(). + * \param port See \ref para_listen(). + * + * This is a simple wrapper for \ref para_listen() which passes a NULL pointer + * as the address information. + * + * \return See \ref para_listen(). + */ +int para_listen_simple(unsigned l4type, uint16_t port) +{ + return para_listen(l4type, NULL, port); +} + /** * Determine IPv4/v6 socket address length. * \param sa Container of IPv4 or IPv6 address. @@ -556,7 +598,7 @@ 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) @@ -601,14 +643,14 @@ 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; @@ -622,28 +664,26 @@ 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)"); @@ -663,36 +703,6 @@ 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. * @@ -772,7 +782,7 @@ __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) { @@ -855,63 +865,88 @@ 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. If a NULL pointer is passed as the name, the function only + * initializes the static variable. */ static int init_unix_addr(struct sockaddr_un *u, const char *name) { - if (strlen(name) >= UNIX_PATH_MAX) - return -E_NAME_TOO_LONG; + static int use_abstract; + 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 "); + } + if (!name) + return 0; + if (strlen(name) + 1 >= UNIX_PATH_MAX) + return -E_NAME_TOO_LONG; + 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); - if (ret < 0) + ret = init_unix_addr(&unix_addr, name); + if (ret <= 0) /* error, or name was NULL */ 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); @@ -929,7 +964,7 @@ 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) { @@ -937,17 +972,15 @@ 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; @@ -963,16 +996,17 @@ 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) { @@ -985,7 +1019,7 @@ 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(); @@ -1003,7 +1037,7 @@ 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; } @@ -1019,17 +1053,17 @@ 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; @@ -1058,7 +1092,7 @@ 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)); }