increase socket buffer size for firemon, bug #2700

1 files changed, 25 insertions, 6 deletions

diff --git a/src/firemon/procevent.c b/src/firemon/procevent.c
index b79f12362..762d22514 100644
--- a/src/firemon/procevent.c
+++ b/src/firemon/procevent.c
@@ -173,6 +173,20 @@ static int procevent_netlink_setup(void) {
         if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0)
                 goto errexit;
 
+        // set a large socket rx buffer
+        // the regular default value as set in /proc/sys/net/core/rmem_default will fill the
+        //            buffer much quicker than we can process it
+        int bsize = 1024 * 1024; // 1MB
+        socklen_t blen = sizeof(int);
+        if (setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE, &bsize, blen) == -1)
+                fprintf(stderr, "Warning: cannot set rx buffer size, using default system value\n");
+        else if (arg_debug) {
+                if (getsockopt(sock, SOL_SOCKET, SO_RCVBUF, &bsize, &blen) == -1)
+                        fprintf(stderr, "Error: cannot read rx buffer size\n");
+                else
+                        printf("rx buffer size %d\n", bsize / 2); // the value returned is duble the real one, see man 7 socket
+        }
+
         // send monitoring message
         struct nlmsghdr nlmsghdr;
         memset(&nlmsghdr, 0, sizeof(nlmsghdr));
@@ -244,14 +258,19 @@ static int procevent_monitor(const int sock, pid_t mypid) {
                 }
 
 
-                if ((len = recv(sock, buf, sizeof(buf), 0)) == 0) {
+                if ((len = recv(sock, buf, sizeof(buf), 0)) == 0)
                         return 0;
-                }
                 if (len == -1) {
-                        if (errno == EINTR) {
-                                return 0;
-                        } else {
-                                fprintf(stderr,"recv: %s\n", strerror(errno));
+                        if (errno == EINTR)
+                                continue;
+                        else if (errno == ENOBUFS) {
+                                // rx buffer is full, the kernel started dropping messages
+                                printf("*** Waning *** - message burst received, not all events are printed\n");
+//return -1;
+                                continue;
+                        }
+                        else {
+                                fprintf(stderr,"Error: rx socket recv call, errno %d, %s\n", errno, strerror(errno));
                                 return -1;
                         }
                 }