Implement timeout for connect ipv4/ipv6

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>

diff --git a/src/common/sessiond-comm/Makefile.am b/src/common/sessiond-comm/Makefile.am
index 24063f862b3e30b0119e328578c675b63c99f07b..72375c0e90a8b2a8448a01a1f3ea5a920a88021e 100644 (file)
--- a/src/common/sessiond-comm/Makefile.am
+++ b/src/common/sessiond-comm/Makefile.am
@@ -6,3 +6,4 @@ noinst_LTLIBRARIES = libsessiond-comm.la
 libsessiond_comm_la_SOURCES = sessiond-comm.c sessiond-comm.h \
                               unix.c unix.h inet.c inet.h inet6.c inet6.h \
                               relayd.h
+libsessiond_comm_la_LIBADD = -lrt

diff --git a/src/common/sessiond-comm/inet.c b/src/common/sessiond-comm/inet.c
index b2bd65d9029672efb47a4469ef3632b30a649740..6d729238a575e8ae149d85a8f25693f7a2554400 100644 (file)
--- a/src/common/sessiond-comm/inet.c
+++ b/src/common/sessiond-comm/inet.c
@@ -25,11 +25,18 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include <errno.h>
+#include <fcntl.h>
+#include <time.h>
+#include <poll.h>
 
 #include <common/common.h>
 
 #include "inet.h"
 
+#define MSEC_PER_SEC   1000
+#define NSEC_PER_MSEC  1000000
+#define RECONNECT_DELAY        200     /* ms */
+
 /*
  * INET protocol operations.
  */
@@ -91,6 +98,130 @@ int lttcomm_bind_inet_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.sin,
+                       sizeof(sock->sockaddr.addr.sin));
+}
+
+/*
+ * 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.sin,
+               sizeof(sock->sockaddr.addr.sin));
+       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.
  */
@@ -99,8 +230,11 @@ int lttcomm_connect_inet_sock(struct lttcomm_sock *sock)
 {
        int ret, closeret;
 
-       ret = connect(sock->fd, (struct sockaddr *) &sock->sockaddr.addr.sin,
-                       sizeof(sock->sockaddr.addr.sin));
+       if (lttcomm_get_network_timeout()) {
+               ret = connect_with_timeout(sock);
+       } else {
+               ret = connect_no_timeout(sock);
+       }
        if (ret < 0) {
                PERROR("connect");
                goto error_connect;

diff --git a/src/common/sessiond-comm/inet6.c b/src/common/sessiond-comm/inet6.c
index 8d883740478f0c0cfca365f2334daed6a7669ba5..52e2f8e5853d9abdb6b6bc059998fb8a92e3057c 100644 (file)
--- a/src/common/sessiond-comm/inet6.c
+++ b/src/common/sessiond-comm/inet6.c
@@ -25,11 +25,18 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include <errno.h>
+#include <fcntl.h>
+#include <time.h>
+#include <poll.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.
  */
@@ -91,6 +98,130 @@ 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.
  */
@@ -99,8 +230,11 @@ 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) {
                PERROR("connect inet6");
                goto error_connect;