X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fsocket-util.c;h=12f04321beb9df16b6097f9be3295eec2ff683f8;hb=ca261b65354f522ba43c823221763ca6f4604e2d;hp=935e7477771b494edcc09170c490492b1d62e913;hpb=b2fda3effc787f265b5ad5dfa967ac00627bd075;p=openvswitch diff --git a/lib/socket-util.c b/lib/socket-util.c index 935e7477..12f04321 100644 --- a/lib/socket-util.c +++ b/lib/socket-util.c @@ -59,6 +59,9 @@ VLOG_DEFINE_THIS_MODULE(socket_util); #define O_DIRECTORY 0 #endif +static int getsockopt_int(int fd, int level, int option, const char *optname, + int *valuep); + /* Sets 'fd' to non-blocking mode. Returns 0 if successful, otherwise a * positive errno value. */ int @@ -145,17 +148,46 @@ lookup_ipv6(const char *host_name, struct in6_addr *addr) return 0; } +/* Translates 'host_name', which must be a host name or a string representation + * of an IP address, into a numeric IP address in '*addr'. Returns 0 if + * successful, otherwise a positive errno value. + * + * Most Open vSwitch code should not use this because it causes deadlocks: + * gethostbyname() sends out a DNS request but that starts a new flow for which + * OVS must set up a flow, but it can't because it's waiting for a DNS reply. + * The synchronous lookup also delays other activty. (Of course we can solve + * this but it doesn't seem worthwhile quite yet.) */ +int +lookup_hostname(const char *host_name, struct in_addr *addr) +{ + struct hostent *h; + + if (inet_aton(host_name, addr)) { + return 0; + } + + h = gethostbyname(host_name); + if (h) { + *addr = *(struct in_addr *) h->h_addr; + return 0; + } + + return (h_errno == HOST_NOT_FOUND ? ENOENT + : h_errno == TRY_AGAIN ? EAGAIN + : h_errno == NO_RECOVERY ? EIO + : h_errno == NO_ADDRESS ? ENXIO + : EINVAL); +} + /* Returns the error condition associated with socket 'fd' and resets the * socket's error status. */ int get_socket_error(int fd) { int error; - socklen_t len = sizeof(error); - if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &error, &len) < 0) { - static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10); + + if (getsockopt_int(fd, SOL_SOCKET, SO_ERROR, "SO_ERROR", &error)) { error = errno; - VLOG_ERR_RL(&rl, "getsockopt(SO_ERROR): %s", strerror(error)); } return error; } @@ -190,15 +222,13 @@ check_connection_completion(int fd) int drain_rcvbuf(int fd) { - socklen_t rcvbuf_len; - size_t rcvbuf; + int rcvbuf; - rcvbuf_len = sizeof rcvbuf; - if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &rcvbuf, &rcvbuf_len) < 0) { - static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10); - VLOG_ERR_RL(&rl, "getsockopt(SO_RCVBUF) failed: %s", strerror(errno)); - return errno; + rcvbuf = get_socket_rcvbuf(fd); + if (rcvbuf < 0) { + return -rcvbuf; } + while (rcvbuf > 0) { /* In Linux, specifying MSG_TRUNC in the flags argument causes the * datagram length to be returned, even if that is longer than the @@ -219,6 +249,18 @@ drain_rcvbuf(int fd) return 0; } +/* Returns the size of socket 'sock''s receive buffer (SO_RCVBUF), or a + * negative errno value if an error occurs. */ +int +get_socket_rcvbuf(int sock) +{ + int rcvbuf; + int error; + + error = getsockopt_int(sock, SOL_SOCKET, SO_RCVBUF, "SO_RCVBUF", &rcvbuf); + return error ? -error : rcvbuf; +} + /* Reads and discards up to 'n' datagrams from 'fd', stopping as soon as no * more data can be immediately read. ('fd' should therefore be in * non-blocking mode.)*/ @@ -554,9 +596,7 @@ exit: return error; } -/* Opens a non-blocking IPv4 socket of the specified 'style', binds to - * 'target', and listens for incoming connections. 'target' should be a string - * in the format "[][:]": +/* Parses 'target', which should be a string in the format "[][:]": * * - If 'default_port' is -1, then is required. Otherwise, if * is omitted, then 'default_port' is used instead. @@ -566,106 +606,128 @@ exit: * * - If is omitted then the IP address is wildcarded. * - * 'style' should be SOCK_STREAM (for TCP) or SOCK_DGRAM (for UDP). - * - * For TCP, the socket will have SO_REUSEADDR turned on. - * - * On success, returns a non-negative file descriptor. On failure, returns a - * negative errno value. - * - * If 'sinp' is non-null, then on success the bound address is stored into - * '*sinp'. */ -int -inet_open_passive(int style, const char *target_, int default_port, - struct sockaddr_in *sinp) + * If successful, stores the address into '*sinp' and returns true; otherwise + * zeros '*sinp' and returns false. */ +bool +inet_parse_passive(const char *target_, int default_port, + struct sockaddr_in *sinp) { char *target = xstrdup(target_); char *string_ptr = target; - struct sockaddr_in sin; const char *host_name; const char *port_string; - int fd = 0, error, port; - unsigned int yes = 1; + bool ok = false; + int port; /* Address defaults. */ - memset(&sin, 0, sizeof sin); - sin.sin_family = AF_INET; - sin.sin_addr.s_addr = htonl(INADDR_ANY); - sin.sin_port = htons(default_port); + memset(sinp, 0, sizeof *sinp); + sinp->sin_family = AF_INET; + sinp->sin_addr.s_addr = htonl(INADDR_ANY); + sinp->sin_port = htons(default_port); /* Parse optional port number. */ port_string = strsep(&string_ptr, ":"); if (port_string && str_to_int(port_string, 10, &port)) { - sin.sin_port = htons(port); + sinp->sin_port = htons(port); } else if (default_port < 0) { VLOG_ERR("%s: port number must be specified", target_); - error = EAFNOSUPPORT; goto exit; } /* Parse optional bind IP. */ host_name = strsep(&string_ptr, ":"); - if (host_name && host_name[0]) { - error = lookup_ip(host_name, &sin.sin_addr); - if (error) { - goto exit; - } + if (host_name && host_name[0] && lookup_ip(host_name, &sinp->sin_addr)) { + goto exit; + } + + ok = true; + +exit: + if (!ok) { + memset(sinp, 0, sizeof *sinp); + } + free(target); + return ok; +} + + +/* Opens a non-blocking IPv4 socket of the specified 'style', binds to + * 'target', and listens for incoming connections. Parses 'target' in the same + * way was inet_parse_passive(). + * + * 'style' should be SOCK_STREAM (for TCP) or SOCK_DGRAM (for UDP). + * + * For TCP, the socket will have SO_REUSEADDR turned on. + * + * On success, returns a non-negative file descriptor. On failure, returns a + * negative errno value. + * + * If 'sinp' is non-null, then on success the bound address is stored into + * '*sinp'. */ +int +inet_open_passive(int style, const char *target, int default_port, + struct sockaddr_in *sinp) +{ + struct sockaddr_in sin; + int fd = 0, error; + unsigned int yes = 1; + + if (!inet_parse_passive(target, default_port, &sin)) { + return -EAFNOSUPPORT; } /* Create non-blocking socket, set SO_REUSEADDR. */ fd = socket(AF_INET, style, 0); if (fd < 0) { error = errno; - VLOG_ERR("%s: socket: %s", target_, strerror(error)); - goto exit; + VLOG_ERR("%s: socket: %s", target, strerror(error)); + return -error; } error = set_nonblocking(fd); if (error) { - goto exit_close; + goto error; } if (style == SOCK_STREAM && setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof yes) < 0) { error = errno; - VLOG_ERR("%s: setsockopt(SO_REUSEADDR): %s", target_, strerror(error)); - goto exit_close; + VLOG_ERR("%s: setsockopt(SO_REUSEADDR): %s", target, strerror(error)); + goto error; } /* Bind. */ if (bind(fd, (struct sockaddr *) &sin, sizeof sin) < 0) { error = errno; - VLOG_ERR("%s: bind: %s", target_, strerror(error)); - goto exit_close; + VLOG_ERR("%s: bind: %s", target, strerror(error)); + goto error; } /* Listen. */ - if (listen(fd, 10) < 0) { + if (style == SOCK_STREAM && listen(fd, 10) < 0) { error = errno; - VLOG_ERR("%s: listen: %s", target_, strerror(error)); - goto exit_close; + VLOG_ERR("%s: listen: %s", target, strerror(error)); + goto error; } if (sinp) { socklen_t sin_len = sizeof sin; if (getsockname(fd, (struct sockaddr *) &sin, &sin_len) < 0){ error = errno; - VLOG_ERR("%s: getsockname: %s", target_, strerror(error)); - goto exit_close; + VLOG_ERR("%s: getsockname: %s", target, strerror(error)); + goto error; } if (sin.sin_family != AF_INET || sin_len != sizeof sin) { - VLOG_ERR("%s: getsockname: invalid socket name", target_); - goto exit_close; + error = EAFNOSUPPORT; + VLOG_ERR("%s: getsockname: invalid socket name", target); + goto error; } *sinp = sin; } - error = 0; - goto exit; + return fd; -exit_close: +error: close(fd); -exit: - free(target); - return error ? -error : fd; + return -error; } /* Returns a readable and writable fd for /dev/null, if successful, otherwise @@ -796,13 +858,27 @@ xpipe(int fds[2]) } static int -getsockopt_int(int fd, int level, int optname, int *valuep) +getsockopt_int(int fd, int level, int option, const char *optname, int *valuep) { - socklen_t len = sizeof *valuep; + static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10); + socklen_t len; + int value; + int error; - return (getsockopt(fd, level, optname, valuep, &len) ? errno - : len == sizeof *valuep ? 0 - : EINVAL); + len = sizeof value; + if (getsockopt(fd, level, option, &value, &len)) { + error = errno; + VLOG_ERR_RL(&rl, "getsockopt(%s): %s", optname, strerror(error)); + } else if (len != sizeof value) { + error = EINVAL; + VLOG_ERR_RL(&rl, "getsockopt(%s): value is %u bytes (expected %zu)", + optname, (unsigned int) len, sizeof value); + } else { + error = 0; + } + + *valuep = error ? 0 : value; + return error; } static void @@ -840,7 +916,8 @@ describe_sockaddr(struct ds *string, int fd, #define SO_PROTOCOL 38 #endif - if (!getsockopt_int(fd, SOL_SOCKET, SO_PROTOCOL, &protocol)) { + if (!getsockopt_int(fd, SOL_SOCKET, SO_PROTOCOL, "SO_PROTOCOL", + &protocol)) { switch (protocol) { case NETLINK_ROUTE: ds_put_cstr(string, "NETLINK_ROUTE");