X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=net.c;h=49026db0ec91a7b4a1d3d0917723720eb8d0ba30;hp=64693bef51e1b339f398cada9cb07ef3b0c8f05f;hb=8aa0f575bcca12ab63ab53141c2144448c457478;hpb=8a63543fdfbd3b5d00e4afecfbc397795a49ed04 diff --git a/net.c b/net.c index 64693bef..49026db0 100644 --- a/net.c +++ b/net.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2005-2010 Andre Noll + * Copyright (C) 2005-2011 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ @@ -25,13 +25,10 @@ #define AI_ADDRCONFIG 0 #endif -#include #include -#include #include "para.h" #include "error.h" -#include "crypt.h" #include "net.h" #include "string.h" #include "list.h" @@ -288,7 +285,7 @@ struct flowopts *flowopt_new(void) * \sa setsockopt(2) */ void flowopt_add(struct flowopts *fo, int lev, int opt, - char *name, const void *val, int len) + const char *name, const void *val, int len) { struct pre_conn_opt *new = para_malloc(sizeof(*new)); @@ -309,7 +306,7 @@ void flowopt_add(struct flowopts *fo, int lev, int opt, } void flowopt_add_bool(struct flowopts *fo, int lev, int opt, - char *optname, bool on_or_off) + const char *optname, bool on_or_off) { int on = on_or_off; /* kernel takes 'int' */ @@ -380,8 +377,8 @@ int makesock(unsigned l4type, bool passive, const char *host, uint16_t port_number, struct flowopts *fo) { - struct addrinfo *local = NULL, *src, - *remote = NULL, *dst, hints; + 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); @@ -414,7 +411,8 @@ int makesock(unsigned l4type, bool passive, layer4_name(l4type), host? host : (passive? "[loopback]" : "[localhost]"), port, gai_strerror(rc)); - return -E_ADDRESS_LOOKUP; + rc = -E_ADDRESS_LOOKUP; + goto out; } /* Iterate over all src/dst combination, exhausting dst first */ @@ -439,7 +437,8 @@ int makesock(unsigned l4type, bool passive, close(sockfd); PARA_ERROR_LOG("can not set SO_REUSEADDR: %s\n", strerror(rc)); - return -ERRNO_TO_PARA_ERROR(rc); + rc = -ERRNO_TO_PARA_ERROR(rc); + break; } flowopt_setopts(sockfd, fo); @@ -462,6 +461,7 @@ get_next_src: if (src && (src = src->ai_next)) /* restart inner loop */ dst = remote; } +out: if (local) freeaddrinfo(local); if (remote) @@ -469,11 +469,12 @@ get_next_src: flowopt_cleanup(fo); if (src == NULL && dst == NULL) { - rc = errno; + 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 -ERRNO_TO_PARA_ERROR(rc); + return rc; } return sockfd; } @@ -521,6 +522,14 @@ static socklen_t salen(const struct sockaddr *sa) : sizeof(struct sockaddr_in); } +/** True if @ss holds a v6-mapped-v4 address (RFC 4291, 2.5.5.2) */ +static bool SS_IS_ADDR_V4MAPPED(const struct sockaddr_storage *ss) +{ + const struct sockaddr_in6 *ia6 = (const struct sockaddr_in6 *)ss; + + return ss->ss_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&ia6->sin6_addr); +} + /** * Process IPv4/v6 address, turn v6-mapped-v4 address into normal IPv4 address. * \param ss Container of IPv4/6 address. @@ -531,11 +540,10 @@ static socklen_t salen(const struct sockaddr *sa) static const struct sockaddr * normalize_ip_address(const struct sockaddr_storage *ss) { - const struct sockaddr_in6 *ia6 = (const struct sockaddr_in6 *)ss; - assert(ss->ss_family == AF_INET || ss->ss_family == AF_INET6); - if (ss->ss_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&ia6->sin6_addr)) { + if (SS_IS_ADDR_V4MAPPED(ss)) { + const struct sockaddr_in6 *ia6 = (const struct sockaddr_in6 *)ss; static struct sockaddr_in ia; ia.sin_family = AF_INET; @@ -547,31 +555,49 @@ normalize_ip_address(const struct sockaddr_storage *ss) } /** - * Print numeric host and port number (beware - uses static char). + * Generic/fallback MTU values + * + * These are taken from RFC 1122, RFC 2460, and RFC 5405. + * - RFC 1122, 3.3.3 defines EMTU_S ("Effective MTU for sending") and recommends + * to use an EMTU_S size of of 576 bytes if the IPv4 path MTU is unknown; + * - RFC 2460, 5. requires a minimum IPv6 MTU of 1280 bytes; + * - RFC 5405, 3.2 recommends that if path MTU discovery is not done, + * UDP senders should use the respective minimum values of EMTU_S. + */ +static inline int generic_mtu(const int af_type) +{ + return af_type == AF_INET6 ? 1280 : 576; +} + +/** Crude approximation of IP header overhead - neglecting options. */ +static inline int estimated_header_overhead(const int af_type) +{ + return af_type == AF_INET6 ? 40 : 20; +} + +/** + * Get the maximum transport-layer message size (MMS_S). + * + * \param sockfd The socket file descriptor. * - * \param sa The IPv4/IPv6 socket address to use. + * The socket must be connected. See RFC 1122, 3.3.3. If the protocol familiy + * could not be determined, \p AF_INET is assumed. * - * \sa getnameinfo(3), services(5), nsswitch.conf(5) + * \return The maximum message size of the address family type. */ -static char *host_and_port(const struct sockaddr_storage *ss) +int generic_max_transport_msg_size(int sockfd) { - const struct sockaddr *sa = normalize_ip_address(ss); - char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV]; - static char output[sizeof(hbuf) + sizeof(sbuf) + 2]; - int ret; + struct sockaddr_storage ss; + socklen_t sslen = sizeof(ss); + int af_type = AF_INET; - ret = getnameinfo(sa, salen(sa), - hbuf, sizeof(hbuf), - sbuf, sizeof(sbuf), - NI_NUMERICHOST); - if (ret == 0) { - snprintf(output, sizeof(output), "%s#%s", hbuf, sbuf); - } else { - snprintf(output, sizeof(output), "(unknown)"); - PARA_WARNING_LOG("hostname lookup error (%s).\n", - gai_strerror(ret)); + if (getpeername(sockfd, (struct sockaddr *)&ss, &sslen) < 0) { + PARA_ERROR_LOG("can not determine remote address type: %s\n", + strerror(errno)); + } else if (!SS_IS_ADDR_V4MAPPED(&ss)) { + af_type = ss.ss_family; } - return output; + return generic_mtu(af_type) - estimated_header_overhead(af_type); } /** @@ -582,23 +608,38 @@ static char *host_and_port(const struct sockaddr_storage *ss) * remote side. * * \return A static character string identifying hostname and port of the - * chosen side. + * chosen side in numeric host:port format. * - * \sa getsockname(2), getpeername(2). + * \sa getsockname(2), getpeername(2), parse_url(), getnameinfo(3), + * services(5), nsswitch.conf(5). */ -static char *__get_sock_name(int fd, int (*getname)(int, struct sockaddr*, - socklen_t *)) +static char *__get_sock_name(int fd, typeof(getsockname) getname) { struct sockaddr_storage ss; + 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) { - static char *dont_know = "(don't know)"; PARA_ERROR_LOG("can not determine address from fd %d: %s\n", fd, strerror(errno)); - return dont_know; + snprintf(output, sizeof(output), "(unknown)"); + return output; } - return host_and_port(&ss); + sa = normalize_ip_address(&ss); + ret = getnameinfo(sa, salen(sa), hbuf, sizeof(hbuf), sbuf, + sizeof(sbuf), NI_NUMERICHOST | NI_NUMERICSERV); + if (ret) { + PARA_WARNING_LOG("hostname lookup error (%s).\n", + gai_strerror(ret)); + snprintf(output, sizeof(output), "(lookup error)"); + } else if (sa->sa_family == AF_INET6) + snprintf(output, sizeof(output), "[%s]:%s", hbuf, sbuf); + else + snprintf(output, sizeof(output), "%s:%s", hbuf, sbuf); + return output; } /** @@ -756,23 +797,36 @@ int recv_buffer(int fd, char *buf, size_t size) * Wrapper around the accept system call. * * \param fd The listening socket. + * \param rfds An optional fd_set pointer. * \param addr Structure which is filled in with the address of the peer socket. * \param size Should contain the size of the structure pointed to by \a addr. + * \param new_fd Result pointer. * - * Accept incoming connections on \a addr. Retry if interrupted. + * Accept incoming connections on \a addr, retry if interrupted. If \a rfds is + * not \p NULL, return 0 if \a fd is not set in \a rfds without calling accept(). * - * \return The new file descriptor on success, negative on errors. + * \return Negative on errors, zero if no connections are present to be accepted, + * one otherwise. * * \sa accept(2). */ -int para_accept(int fd, void *addr, socklen_t size) +int para_accept(int fd, fd_set *rfds, void *addr, socklen_t size, int *new_fd) { - int new_fd; + int ret; + if (rfds && !FD_ISSET(fd, rfds)) + return 0; do - new_fd = accept(fd, (struct sockaddr *) addr, &size); - while (new_fd < 0 && errno == EINTR); - return new_fd < 0? -ERRNO_TO_PARA_ERROR(errno) : new_fd; + ret = accept(fd, (struct sockaddr *) addr, &size); + while (ret < 0 && errno == EINTR); + + if (ret >= 0) { + *new_fd = ret; + return 1; + } + if (errno == EAGAIN || errno == EWOULDBLOCK) + return 0; + return -ERRNO_TO_PARA_ERROR(errno); } /** @@ -878,15 +932,17 @@ err: * This function creates a local socket for sequenced, reliable, two-way, * connection-based byte streams. * - * \return The file descriptor, on success, negative on errors. + * \return The file descriptor of the connected socket on success, negative on + * errors. * * \sa create_local_socket(), unix(7), connect(2). */ -int create_remote_socket(const char *name) +int connect_local_socket(const char *name) { struct sockaddr_un unix_addr; int fd, ret; + PARA_DEBUG_LOG("connecting to %s\n", name); ret = init_unix_addr(&unix_addr, name); if (ret < 0) return ret;