uloop: allow passing 0 as timeout to uloop_run
[project/libubox.git] / usock.c
diff --git a/usock.c b/usock.c
index 613b2dd..0ce5390 100644 (file)
--- a/usock.c
+++ b/usock.c
+/*
+ * usock - socket helper functions
+ *
+ * Copyright (C) 2010 Steven Barth <steven@midlink.org>
+ * Copyright (C) 2011-2012 Felix Fietkau <nbd@openwrt.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <netdb.h>
+#include <poll.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <errno.h>
 #include <string.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <poll.h>
 
 #include "usock.h"
+#include "utils.h"
 
-int usock(int type, const char *host, const char *service) {
-       int sock = -1;
+static void usock_set_flags(int sock, unsigned int type)
+{
+       if (!(type & USOCK_NOCLOEXEC))
+               fcntl(sock, F_SETFD, fcntl(sock, F_GETFD) | FD_CLOEXEC);
 
-       if (service && !(type & USOCK_UNIX)) {
-               struct addrinfo *result, *rp;
-
-               struct addrinfo hints = {
-                       .ai_family = (type & USOCK_IPV6ONLY) ? AF_INET6 :
-                               (type & USOCK_IPV4ONLY) ? AF_INET : AF_UNSPEC,
-                       .ai_socktype = ((type & 0xff) == USOCK_TCP)
-                               ? SOCK_STREAM : SOCK_DGRAM,
-                       .ai_flags = AI_ADDRCONFIG
-                               | ((type & USOCK_SERVER) ? AI_PASSIVE : 0)
-                               | ((type & USOCK_NUMERIC) ? AI_NUMERICHOST : 0),
-               };
-
-               if (getaddrinfo(host, service, &hints, &result)) {
-                       return -1;
-               }
+       if (type & USOCK_NONBLOCK)
+               fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) | O_NONBLOCK);
+}
 
-               for (rp = result; rp != NULL; rp = rp->ai_next) {
-                       if ((sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol))
-                       == -1) {
-                               continue;
-                       }
+static int usock_connect(int type, struct sockaddr *sa, int sa_len, int family, int socktype, bool server)
+{
+       int sock;
 
-                       if (!(type & USOCK_NOCLOEXEC)) {
-                               fcntl(sock, F_SETFD, fcntl(sock, F_GETFD) | FD_CLOEXEC);
-                       }
+       sock = socket(family, socktype, 0);
+       if (sock < 0)
+               return -1;
 
-                       if (type & USOCK_NONBLOCK) {
-                               fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) | O_NONBLOCK);
-                       }
+       usock_set_flags(sock, type);
 
-                       if (type & USOCK_SERVER) {
-                               const int one = 1;
-                               setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
-
-                               if (!bind(sock, rp->ai_addr, rp->ai_addrlen)
-                               && ((type & 0xff) != USOCK_TCP || !listen(sock, SOMAXCONN))) {
-                                       break;
-                               }
-                       } else {
-                               if (!connect(sock, rp->ai_addr, rp->ai_addrlen)
-                               || errno == EINPROGRESS) {
-                                       break;
-                               }
-                       }
+       if (server) {
+               const int one = 1;
+               setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
 
-                       close(sock);
-                       sock = -1;
-               }
-               freeaddrinfo(result);
+               if (!bind(sock, sa, sa_len) &&
+                   (socktype != SOCK_STREAM || !listen(sock, SOMAXCONN)))
+                       return sock;
        } else {
-               struct sockaddr_un sun = {.sun_family = AF_UNIX};
-               if (strlen(host) >= sizeof(sun.sun_path)) {
-                       errno = EINVAL;
-                       return -1;
-               }
-               strcpy(sun.sun_path, host);
+               if (!connect(sock, sa, sa_len) || errno == EINPROGRESS)
+                       return sock;
+       }
 
-               if ((sock = socket(AF_UNIX, ((type & 0xff) == USOCK_TCP)
-                               ? SOCK_STREAM : SOCK_DGRAM, 0)) == -1) {
-                       return -1;
-               }
+       close(sock);
+       return -1;
+}
+
+static int usock_unix(int type, const char *host)
+{
+       struct sockaddr_un sun = {.sun_family = AF_UNIX};
+       bool server = !!(type & USOCK_SERVER);
+       int socktype = ((type & 0xff) == USOCK_TCP) ? SOCK_STREAM : SOCK_DGRAM;
+
+       if (strlen(host) >= sizeof(sun.sun_path)) {
+               errno = EINVAL;
+               return -1;
+       }
+       strcpy(sun.sun_path, host);
+
+       return usock_connect(type, (struct sockaddr*)&sun, sizeof(sun), AF_UNIX, socktype, server);
+}
 
-               if (!(type & USOCK_NOCLOEXEC)) {
-                       fcntl(sock, F_SETFD, fcntl(sock, F_GETFD) | FD_CLOEXEC);
+static int
+usock_inet_notimeout(int type, struct addrinfo *result, void *addr)
+{
+       struct addrinfo *rp;
+       int socktype = ((type & 0xff) == USOCK_TCP) ? SOCK_STREAM : SOCK_DGRAM;
+       bool server = !!(type & USOCK_SERVER);
+       int sock;
+
+       for (rp = result; rp != NULL; rp = rp->ai_next) {
+               sock = usock_connect(type, rp->ai_addr, rp->ai_addrlen, rp->ai_family, socktype, server);
+               if (sock >= 0) {
+                       if (addr)
+                               memcpy(addr, rp->ai_addr, rp->ai_addrlen);
+                       return sock;
                }
+       }
+
+       return -1;
+}
+
+static int poll_restart(struct pollfd *fds, int nfds, int timeout)
+{
+       struct timespec ts, cur;
+       int msec = timeout % 1000;
+       int ret;
+
+       clock_gettime(CLOCK_MONOTONIC, &ts);
+
+       ts.tv_nsec += msec * 1000000;
+       if (ts.tv_nsec > 1000000000) {
+               ts.tv_sec++;
+               ts.tv_nsec -= 1000000000;
+       }
+       ts.tv_sec += timeout / 1000;
+
+       while (1) {
+               ret = poll(fds, nfds, timeout);
+               if (ret == EAGAIN)
+                       continue;
+
+               if (ret != EINTR)
+                       return ret;
+
+               clock_gettime(CLOCK_MONOTONIC, &cur);
+               timeout = (ts.tv_sec - cur.tv_sec) * 1000;
+               timeout += (ts.tv_nsec - cur.tv_nsec) / 1000000;
+               if (timeout <= 0)
+                       return 0;
+       }
+}
+
+int usock_inet_timeout(int type, const char *host, const char *service,
+                      void *addr, int timeout)
+{
+       int socktype = ((type & 0xff) == USOCK_TCP) ? SOCK_STREAM : SOCK_DGRAM;
+       bool server = !!(type & USOCK_SERVER);
+       struct addrinfo *result, *rp;
+       struct addrinfo hints = {
+               .ai_family = (type & USOCK_IPV6ONLY) ? AF_INET6 :
+                       (type & USOCK_IPV4ONLY) ? AF_INET : AF_UNSPEC,
+               .ai_socktype = socktype,
+               .ai_flags = AI_ADDRCONFIG
+                       | ((type & USOCK_SERVER) ? AI_PASSIVE : 0)
+                       | ((type & USOCK_NUMERIC) ? AI_NUMERICHOST : 0),
+       };
+       struct addrinfo *rp_v6 = NULL;
+       struct addrinfo *rp_v4 = NULL;
+       struct pollfd pfds[2] = {
+           { .fd = -1, .events = POLLOUT },
+           { .fd = -1, .events = POLLOUT },
+       };
+       int sock = -1;
+       int i;
+
+       if (getaddrinfo(host, service, &hints, &result))
+               return -1;
+
+       if (timeout <= 0 || server) {
+               sock = usock_inet_notimeout(type, result, addr);
+               goto free_addrinfo;
+       }
 
-               if (type & USOCK_NONBLOCK) {
-                       fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) | O_NONBLOCK);
+       for (rp = result; rp != NULL; rp = rp->ai_next) {
+               if (rp->ai_family == AF_INET6 && !rp_v6)
+                       rp_v6 = rp;
+               if (rp->ai_family == AF_INET && !rp_v4)
+                       rp_v4 = rp;
+       }
+
+       if (!rp_v6 && !rp_v4)
+               goto out;
+
+       if (rp_v6) {
+               rp = rp_v6;
+               pfds[0].fd = usock_connect(type | USOCK_NONBLOCK, rp->ai_addr,
+                                          rp->ai_addrlen, rp->ai_family,
+                                          socktype, server);
+               if (pfds[0].fd < 0) {
+                       rp_v6 = NULL;
+                       goto try_v4;
                }
 
-               if (type & USOCK_SERVER) {
-                       if (bind(sock, (struct sockaddr*)&sun, sizeof(sun)) ||
-                       ((type & 0xff) == USOCK_TCP && listen(sock, SOMAXCONN))) {
-                               close(sock);
-                               return -1;
-                       }
-               } else {
-                       if (connect(sock, (struct sockaddr*)&sun, sizeof(sun))
-                       && errno != EINPROGRESS) {
-                               close(sock);
-                               return -1;
+               if (timeout > 300) {
+                       if (poll_restart(pfds, 1, 300) == 1) {
+                               rp = rp_v6;
+                               sock = pfds[0].fd;
+                               goto out;
                        }
                }
+               timeout -= 300;
+       }
+
+try_v4:
+       if (rp_v4) {
+               rp = rp_v4;
+               pfds[1].fd = usock_connect(type | USOCK_NONBLOCK, rp->ai_addr,
+                                                rp->ai_addrlen, rp->ai_family,
+                                                socktype, server);
+               if (pfds[1].fd < 0) {
+                       rp_v4 = NULL;
+                       if (!rp_v6)
+                               goto out;
+                       goto wait;
+               }
+       }
+
+wait:
+       poll_restart(pfds + !rp_v6, !!rp_v6 + !!rp_v4, timeout);
+       if (pfds[0].revents & POLLOUT) {
+               rp = rp_v6;
+               sock = pfds[0].fd;
+               goto out;
        }
+
+       if (pfds[1].revents & POLLOUT) {
+               rp = rp_v4;
+               sock = pfds[1].fd;
+               goto out;
+       }
+
+out:
+       for (i = 0; i < 2; i++) {
+               int fd = pfds[i].fd;
+               if (fd >= 0 && fd != sock)
+                       close(fd);
+       }
+
+       if (!(type & USOCK_NONBLOCK))
+               fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) & ~O_NONBLOCK);
+
+       if (addr && sock >= 0)
+               memcpy(addr, rp->ai_addr, rp->ai_addrlen);
+free_addrinfo:
+       freeaddrinfo(result);
        return sock;
 }
+
+const char *usock_port(int port)
+{
+       static char buffer[sizeof("65535\0")];
+
+       if (port < 0 || port > 65535)
+               return NULL;
+
+       snprintf(buffer, sizeof(buffer), "%u", port);
+
+       return buffer;
+}
+
+int usock(int type, const char *host, const char *service) {
+       int sock;
+
+       if (type & USOCK_UNIX)
+               sock = usock_unix(type, host);
+       else
+               sock = usock_inet(type, host, service, NULL);
+
+       if (sock < 0)
+               return -1;
+
+       return sock;
+}
+
+int usock_wait_ready(int fd, int msecs) {
+       struct pollfd fds[1];
+       int res;
+
+       fds[0].fd = fd;
+       fds[0].events = POLLOUT;
+
+       res = poll(fds, 1, msecs);
+       if (res < 0) {
+               return errno;
+       } else if (res == 0) {
+               return -ETIMEDOUT;
+       } else {
+               int err = 0;
+               socklen_t optlen = sizeof(err);
+
+               res = getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &optlen);
+               if (res)
+                       return errno;
+               if (err)
+                       return err;
+       }
+
+       return 0;
+}