X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=net.c;h=eaa1cfb81146b3dc4fd7bb11cd41df447dc0e825;hp=4d52e4a4e98bd53b3099f7cf8535372a4a270cff;hb=refs%2Fheads%2Fmaint;hpb=c5e38315901ea63efd169af5d4ba3f3c66db7de9 diff --git a/net.c b/net.c index 4d52e4a4..91200fc0 100644 --- a/net.c +++ b/net.c @@ -1,33 +1,17 @@ -/* - * 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 +#include +#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" @@ -43,8 +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, @@ -104,7 +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) { @@ -142,11 +126,11 @@ static bool host_string_ok(const char *host) * \param hostlen The maximum length of \a host. * \param port To return the port number (if any) of \a url. * - * \return Pointer to \a host, or NULL if failed. - * If NULL is returned, \a host and \a portnum are undefined. If no - * port number was present in \a url, \a portnum is set to -1. + * \return Pointer to \a host, or \p NULL if failed. If \p NULL is returned, + * \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, @@ -168,16 +152,15 @@ char *parse_url(const char *url, if (*o++ != ']' || (*o != '\0' && *o != ':')) goto failed; } else { - for (; (*c = *o == ':'? '\0' : *o); c++, o++) - if (c == end) + for (; (*c = *o == ':'? '\0' : *o); c++, o++) { + if (c == end && o[1]) goto failed; + } } 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; failed: @@ -185,13 +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) { @@ -203,7 +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); } @@ -215,7 +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) { @@ -247,7 +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() */ @@ -264,6 +278,12 @@ 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)); @@ -282,7 +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) @@ -305,14 +325,6 @@ 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, - const 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) { @@ -330,7 +342,14 @@ 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; @@ -346,155 +365,183 @@ static void flowopt_cleanup(struct flowopts *fo) } /** - * Resolve IPv4/IPv6 address and create a ready-to-use active or passive socket. + * Resolve an IPv4/IPv6 address. * * \param l4type The layer-4 type (\p IPPROTO_xxx). - * \param passive Whether this is a passive (1) or active (0) socket. + * \param passive Whether \p AI_PASSIVE should be included as hint. * \param host Remote or local hostname or IPv/6 address string. - * \param port_number Decimal port number. - * \param fo Socket options to be set before making the connection. + * \param port_number Used to set the port in each returned address structure. + * \param result addrinfo structures are returned here. * - * This creates a ready-made IPv4/v6 socket structure after looking up the - * necessary parameters. The interpretation of \a host depends on the value of - * \a passive: - * - on a passive socket host is interpreted as an interface IPv4/6 address - * (can be left NULL); - * - on an active socket, \a host is the peer DNS name or IPv4/6 address - * to connect to; - * - \a port_number is in either case the numeric port number (not service - * string). - * - * Furthermore, 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. - * - * \return This function returns 1 on success and \a -E_ADDRESS_LOOKUP when no - * matching connection could be set up (with details in the error log). - * - * \sa ipv6(7), getaddrinfo(3), bind(2), connect(2). - */ -int makesock(unsigned l4type, bool passive, - const char *host, uint16_t port_number, - struct flowopts *fo) -{ - 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); + * The interpretation of \a host depends on the value of \a passive. On a + * passive socket host is interpreted as an interface IPv4/6 address (can be + * left NULL). On an active socket, \a host is the peer DNS name or IPv4/6 + * address to connect to. + * + * \return Standard. + * + * \sa getaddrinfo(3). + */ +int lookup_address(unsigned l4type, bool passive, const char *host, + int port_number, struct addrinfo **result) +{ + int ret; char port[6]; /* port number has at most 5 digits */ + struct addrinfo *addr = NULL, hints; - sprintf(port, "%u", port_number); + *result = NULL; + sprintf(port, "%d", port_number & 0xffff); /* Set up address hint structure */ memset(&hints, 0, sizeof(hints)); - hints.ai_family = l3type; - hints.ai_socktype = socktype; - /* + hints.ai_family = AF_UNSPEC; + hints.ai_socktype = sock_type(l4type); + /* * getaddrinfo does not support SOCK_DCCP, so for the sake of lookup * (and only then) pretend to be UDP. */ if (l4type == IPPROTO_DCCP) hints.ai_socktype = SOCK_DGRAM; - /* only use addresses available on the host */ hints.ai_flags = AI_ADDRCONFIG; - if (l3type == AF_INET6) - /* use v4-mapped-v6 if no v6 addresses found */ - hints.ai_flags |= AI_V4MAPPED | AI_ALL; - if (passive && host == NULL) hints.ai_flags |= AI_PASSIVE; - /* Obtain local/remote address information */ - if ((rc = getaddrinfo(host, port, &hints, passive ? &local : &remote))) { - PARA_ERROR_LOG("can not resolve %s address %s#%s: %s.\n", - layer4_name(l4type), - host? host : (passive? "[loopback]" : "[localhost]"), - port, gai_strerror(rc)); - rc = -E_ADDRESS_LOOKUP; - goto out; + ret = getaddrinfo(host, port, &hints, &addr); + if (ret != 0) { + PARA_ERROR_LOG("can not resolve %s address %s#%s: %s\n", + layer4_name(l4type), + host? host : (passive? "[loopback]" : "[localhost]"), + port, gai_strerror(ret)); + return -E_ADDRESS_LOOKUP; } + *result = addr; + return 1; +} - /* Iterate over all src/dst combination, exhausting dst first */ - for (src = local, dst = remote; src != NULL || dst != NULL; /* no op */ ) { - if (src && dst && src->ai_family == AF_INET - && dst->ai_family == AF_INET6) - goto get_next_dst; /* v4 -> v6 is not possible */ - - sockfd = socket(src ? src->ai_family : dst->ai_family, - socktype, l4type); - if (sockfd < 0) - goto get_next_dst; +/** + * Create an active or passive socket. + * + * \param l4type \p IPPROTO_TCP, \p IPPROTO_UDP, or \p IPPROTO_DCCP. + * \param passive Whether to call bind(2) or connect(2). + * \param ai Address information as obtained from \ref lookup_address(). + * \param fo Socket options to be set before making the connection. + * + * 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 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). + */ +int makesock_addrinfo(unsigned l4type, bool passive, struct addrinfo *ai, + struct flowopts *fo) +{ + 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) { + 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) { + PARA_NOTICE_LOG("connect(): %s\n", + strerror(errno)); + close(fd); + continue; + } + return fd; + } /* * 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) { - rc = errno; - close(sockfd); - PARA_ERROR_LOG("can not set SO_REUSEADDR: %s\n", - strerror(rc)); - rc = -ERRNO_TO_PARA_ERROR(rc); - break; - } - flowopt_setopts(sockfd, fo); - - if (src) { - if (bind(sockfd, src->ai_addr, src->ai_addrlen) < 0) { - close(sockfd); - goto get_next_src; - } - if (!dst) /* bind-only completed successfully */ - break; + if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, + sizeof(on)) == -1) { + PARA_NOTICE_LOG("setsockopt(): %s\n", strerror(errno)); + 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) { + PARA_NOTICE_LOG("bind(): %s\n", strerror(errno)); + close(fd); continue; -get_next_src: - if (src && (src = src->ai_next)) /* restart inner loop */ - dst = remote; + } + return fd; } -out: - if (local) - freeaddrinfo(local); - if (remote) - freeaddrinfo(remote); - flowopt_cleanup(fo); - - if (src == NULL && dst == NULL) { - 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 rc; + return -E_MAKESOCK; +} + +/** + * Resolve IPv4/IPv6 address and create a ready-to-use active or passive socket. + * + * \param l4type The layer-4 type (\p IPPROTO_xxx). + * \param passive Whether this is a passive or active socket. + * \param host Passed to \ref lookup_address(). + * \param port_number Passed to \ref lookup_address(). + * \param fo Passed to \ref makesock_addrinfo(). + * + * This creates a ready-made IPv4/v6 socket structure after looking up the + * necessary parameters. The function first calls \ref lookup_address() and + * passes the address information to makesock_addrinfo() to create and + * initialize the socket. + * + * \return The newly created file descriptor on success, a negative error code + * on failure. + * + * \sa \ref lookup_address(), \ref makesock_addrinfo(). + */ +int makesock(unsigned l4type, bool passive, const char *host, uint16_t port_number, + struct flowopts *fo) +{ + struct addrinfo *ai; + int ret = lookup_address(l4type, passive, host, port_number, &ai); + + if (ret >= 0) + ret = makesock_addrinfo(l4type, passive, ai, fo); + if (ai) + freeaddrinfo(ai); + if (ret < 0) { + PARA_ERROR_LOG("can not create %s socket %s#%d.\n", + layer4_name(l4type), host? host : (passive? + "[loopback]" : "[localhost]"), port_number); } - return sockfd; + return ret; } /** * 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) { @@ -508,6 +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. @@ -535,7 +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) @@ -580,14 +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; @@ -601,28 +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)"); @@ -643,50 +704,46 @@ static char *__get_sock_name(int fd, typeof(getsockname) getname) } /** - * Look up the local side of a connected socket structure. - * - * \param sockfd The file descriptor of the socket. + * Extract IPv4 or IPv6-mapped-IPv4 address from sockaddr_storage. * - * \return A pointer to a static buffer containing hostname an port. This - * buffer must not be freed by the caller. + * \param ss Container of IPv4/6 address. + * \param ia Extracted IPv4 address (different from 0) or 0 if unsuccessful. * - * \sa remote_name(). + * \sa RFC 3493. */ -char *local_name(int sockfd) +void extract_v4_addr(const struct sockaddr_storage *ss, struct in_addr *ia) { - return __get_sock_name(sockfd, getsockname); -} + const struct sockaddr *sa = normalize_ip_address(ss); -/** - * 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); + memset(ia, 0, sizeof(*ia)); + if (sa->sa_family == AF_INET) + *ia = ((struct sockaddr_in *)sa)->sin_addr; } /** - * 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. + * Compare the address part of IPv4/6 addresses. * - * \sa RFC 3493 + * \param sa1 First address. + * \param sa2 Second address. + * + * \return True iff the IP address of \a sa1 and \a sa2 match. */ -struct in_addr extract_v4_addr(const struct sockaddr_storage *ss) +bool sockaddr_equal(const struct sockaddr *sa1, const struct sockaddr *sa2) { - struct in_addr ia = {.s_addr = 0}; - const struct sockaddr *sa = normalize_ip_address(ss); - - if (sa->sa_family == AF_INET) - ia = ((struct sockaddr_in *)sa)->sin_addr; - return ia; + 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; } /** @@ -725,7 +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) { @@ -808,63 +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); @@ -882,7 +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) { @@ -890,17 +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; @@ -916,16 +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) { @@ -938,7 +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(); @@ -956,7 +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; } @@ -972,17 +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; @@ -1011,7 +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)); }