inet/inet6 sockets: apply timeout
[lttng-tools.git] / src / common / sessiond-comm / inet6.c
index 8fe0276013bce4b0f6e613b6230d55b377ffe58f..5b137c4eb3a73430ad364b9e9acacce4f6126d3b 100644 (file)
 #include <sys/types.h>
 #include <unistd.h>
 #include <errno.h>
+#include <fcntl.h>
+#include <time.h>
+#include <poll.h>
 
-#include <common/defaults.h>
-#include <common/error.h>
+#include <common/common.h>
 
 #include "inet6.h"
 
+#define MSEC_PER_SEC   1000
+#define NSEC_PER_MSEC  1000000
+#define RECONNECT_DELAY        200     /* ms */
+
 /*
  * INET protocol operations.
  */
@@ -47,10 +53,11 @@ static const struct lttcomm_proto_ops inet6_ops = {
 /*
  * Creates an PF_INET socket.
  */
-__attribute__((visibility("hidden")))
+LTTNG_HIDDEN
 int lttcomm_create_inet6_sock(struct lttcomm_sock *sock, int type, int proto)
 {
        int val = 1, ret;
+       unsigned long timeout;
 
        /* Create server socket */
        if ((sock->fd = socket(PF_INET6, type, proto)) < 0) {
@@ -68,6 +75,17 @@ int lttcomm_create_inet6_sock(struct lttcomm_sock *sock, int type, int proto)
                PERROR("setsockopt inet6");
                goto error;
        }
+       timeout = lttcomm_get_network_timeout();
+       if (timeout) {
+               ret = lttcomm_setsockopt_rcv_timeout(sock->fd, timeout);
+               if (ret) {
+                       goto error;
+               }
+               ret = lttcomm_setsockopt_snd_timeout(sock->fd, timeout);
+               if (ret) {
+                       goto error;
+               }
+       }
 
        return 0;
 
@@ -78,7 +96,7 @@ error:
 /*
  * Bind socket and return.
  */
-__attribute__((visibility("hidden")))
+LTTNG_HIDDEN
 int lttcomm_bind_inet6_sock(struct lttcomm_sock *sock)
 {
        int ret;
@@ -92,21 +110,145 @@ int lttcomm_bind_inet6_sock(struct lttcomm_sock *sock)
        return ret;
 }
 
+static
+int connect_no_timeout(struct lttcomm_sock *sock)
+{
+       return connect(sock->fd, (struct sockaddr *) &sock->sockaddr.addr.sin6,
+                       sizeof(sock->sockaddr.addr.sin6));
+}
+
+/*
+ * Return time_a - time_b  in milliseconds.
+ */
+static
+unsigned long time_diff_ms(struct timespec *time_a,
+               struct timespec *time_b)
+{
+       time_t sec_diff;
+       long nsec_diff;
+       unsigned long result_ms;
+
+       sec_diff = time_a->tv_sec - time_b->tv_sec;
+       nsec_diff = time_a->tv_nsec - time_b->tv_nsec;
+
+       result_ms = sec_diff * MSEC_PER_SEC;
+       result_ms += nsec_diff / NSEC_PER_MSEC;
+       return result_ms;
+}
+
+static
+int connect_with_timeout(struct lttcomm_sock *sock)
+{
+       unsigned long timeout = lttcomm_get_network_timeout();
+       int ret, flags, connect_ret;
+       struct timespec orig_time, cur_time;
+
+       ret = fcntl(sock->fd, F_GETFL, 0);
+       if (ret == -1) {
+               PERROR("fcntl");
+               return -1;
+       }
+       flags = ret;
+
+       /* Set socket to nonblock */
+       ret = fcntl(sock->fd, F_SETFL, flags | O_NONBLOCK);
+       if (ret == -1) {
+               PERROR("fcntl");
+               return -1;
+       }
+
+       ret = clock_gettime(CLOCK_MONOTONIC, &orig_time);
+       if (ret == -1) {
+               PERROR("clock_gettime");
+               return -1;
+       }
+
+       connect_ret = connect(sock->fd,
+               (struct sockaddr *) &sock->sockaddr.addr.sin6,
+               sizeof(sock->sockaddr.addr.sin6));
+       if (connect_ret == -1 && errno != EAGAIN
+                       && errno != EWOULDBLOCK
+                       && errno != EINPROGRESS) {
+               goto error;
+       } else if (!connect_ret) {
+               /* Connect succeeded */
+               goto success;
+       }
+
+       /*
+        * Perform poll loop following EINPROGRESS recommendation from
+        * connect(2) man page.
+        */
+       do {
+               struct pollfd fds;
+
+               fds.fd = sock->fd;
+               fds.events = POLLOUT;
+               fds.revents = 0;
+               ret = poll(&fds, 1, RECONNECT_DELAY);
+               if (ret < 0) {
+                       goto error;
+               } else if (ret > 0) {
+                       int optval;
+                       socklen_t optval_len = sizeof(optval);
+
+                       if (!(fds.revents & POLLOUT)) {
+                               /* Either hup or error */
+                               errno = EPIPE;
+                               goto error;
+                       }
+                       /* got something */
+                       ret = getsockopt(sock->fd, SOL_SOCKET,
+                               SO_ERROR, &optval, &optval_len);
+                       if (ret) {
+                               goto error;
+                       }
+                       if (!optval) {
+                               connect_ret = 0;
+                               goto success;
+                       } else {
+                               goto error;
+                       }
+               }
+               /* ret == 0: timeout */
+               ret = clock_gettime(CLOCK_MONOTONIC, &cur_time);
+               if (ret == -1) {
+                       PERROR("clock_gettime");
+                       connect_ret = ret;
+                       goto error;
+               }
+       } while (time_diff_ms(&cur_time, &orig_time) < timeout);
+
+       /* Timeout */
+       errno = ETIMEDOUT;
+       connect_ret = -1;
+
+success:
+       /* Restore initial flags */
+       ret = fcntl(sock->fd, F_SETFL, flags);
+       if (ret == -1) {
+               PERROR("fcntl");
+               /* Continue anyway */
+       }
+error:
+       return connect_ret;
+}
+
 /*
  * Connect PF_INET socket.
  */
-__attribute__((visibility("hidden")))
+LTTNG_HIDDEN
 int lttcomm_connect_inet6_sock(struct lttcomm_sock *sock)
 {
        int ret, closeret;
 
-       ret = connect(sock->fd, (struct sockaddr *) &sock->sockaddr.addr.sin6,
-                       sizeof(sock->sockaddr.addr.sin6));
+       if (lttcomm_get_network_timeout()) {
+               ret = connect_with_timeout(sock);
+       } else {
+               ret = connect_no_timeout(sock);
+       }
        if (ret < 0) {
-               /*
-                * Don't print message on connect error, because connect is used in
-                * normal execution to detect if sessiond is alive.
-                */
+               PERROR("connect inet6");
                goto error_connect;
        }
 
@@ -125,11 +267,11 @@ error_connect:
  * Do an accept(2) on the sock and return the new lttcomm socket. The socket
  * MUST be bind(2) before.
  */
-__attribute__((visibility("hidden")))
+LTTNG_HIDDEN
 struct lttcomm_sock *lttcomm_accept_inet6_sock(struct lttcomm_sock *sock)
 {
        int new_fd;
-       socklen_t len = 0;
+       socklen_t len;
        struct lttcomm_sock *new_sock;
 
        if (sock->proto == LTTCOMM_SOCK_UDP) {
@@ -145,6 +287,8 @@ struct lttcomm_sock *lttcomm_accept_inet6_sock(struct lttcomm_sock *sock)
                goto error;
        }
 
+       len = sizeof(new_sock->sockaddr.addr.sin6);
+
        /* Blocking call */
        new_fd = accept(sock->fd,
                        (struct sockaddr *) &new_sock->sockaddr.addr.sin6, &len);
@@ -167,7 +311,7 @@ error:
 /*
  * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
  */
-__attribute__((visibility("hidden")))
+LTTNG_HIDDEN
 int lttcomm_listen_inet6_sock(struct lttcomm_sock *sock, int backlog)
 {
        int ret;
@@ -198,13 +342,14 @@ end:
  *
  * Return the size of received data.
  */
-__attribute__((visibility("hidden")))
+LTTNG_HIDDEN
 ssize_t lttcomm_recvmsg_inet6_sock(struct lttcomm_sock *sock, void *buf,
                size_t len, int flags)
 {
        struct msghdr msg;
        struct iovec iov[1];
        ssize_t ret = -1;
+       size_t len_last;
 
        memset(&msg, 0, sizeof(msg));
 
@@ -216,16 +361,21 @@ ssize_t lttcomm_recvmsg_inet6_sock(struct lttcomm_sock *sock, void *buf,
        msg.msg_name = (struct sockaddr *) &sock->sockaddr.addr.sin6;
        msg.msg_namelen = sizeof(sock->sockaddr.addr.sin6);
 
-       if (flags == 0) {
-               flags = MSG_WAITALL;
-       }
-
        do {
+               len_last = iov[0].iov_len;
                ret = recvmsg(sock->fd, &msg, flags);
-       } while (ret < 0 && errno == EINTR);
+               if (ret > 0) {
+                       iov[0].iov_base += ret;
+                       iov[0].iov_len -= ret;
+                       assert(ret <= len_last);
+               }
+       } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));
        if (ret < 0) {
-               PERROR("recvmsg inet6");
+               PERROR("recvmsg inet");
+       } else if (ret > 0) {
+               ret = len;
        }
+       /* Else ret = 0 meaning an orderly shutdown. */
 
        return ret;
 }
@@ -235,7 +385,7 @@ ssize_t lttcomm_recvmsg_inet6_sock(struct lttcomm_sock *sock, void *buf,
  *
  * Return the size of sent data.
  */
-__attribute__((visibility("hidden")))
+LTTNG_HIDDEN
 ssize_t lttcomm_sendmsg_inet6_sock(struct lttcomm_sock *sock, void *buf,
                size_t len, int flags)
 {
@@ -278,7 +428,7 @@ ssize_t lttcomm_sendmsg_inet6_sock(struct lttcomm_sock *sock, void *buf,
 /*
  * Shutdown cleanly and close.
  */
-__attribute__((visibility("hidden")))
+LTTNG_HIDDEN
 int lttcomm_close_inet6_sock(struct lttcomm_sock *sock)
 {
        int ret;
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