increase socket buffer size for firemon, bug #2700

4 files changed, 32 insertions, 7 deletions

diff --git a/src/firemon/firemon.c b/src/firemon/firemon.c
index b3c435d9e..dad3b0afb 100644
--- a/src/firemon/firemon.c
+++ b/src/firemon/firemon.c
@@ -26,6 +26,7 @@
 #include <sys/stat.h>
 
 pid_t skip_process = 0;
+int arg_debug = 0;
 static int arg_route = 0;
 static int arg_arp = 0;
 static int arg_tree = 0;
@@ -142,7 +143,8 @@ int main(int argc, char **argv) {
                         printf("firemon version %s\n\n", VERSION);
                         return 0;
                 }
-
+                else if (strcmp(argv[i], "--debug") == 0)
+                        arg_debug = 1;
                 // options without a pid argument
                 else if (strcmp(argv[i], "--top") == 0)
                         arg_top = 1;
diff --git a/src/firemon/firemon.h b/src/firemon/firemon.h
index 2e5647c2f..7f8bc698c 100644
--- a/src/firemon/firemon.h
+++ b/src/firemon/firemon.h
@@ -29,6 +29,9 @@
 #include "../include/pid.h"
 #include "../include/common.h"
 
+// main.c
+extern int arg_debug;
+
 // clear screen
 static inline void firemon_clrscr(void) {
         printf("\033[2J\033[1;1H");
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;
                         }
                 }
diff --git a/src/firemon/usage.c b/src/firemon/usage.c
index 3b9fe96c0..196fc32c3 100644
--- a/src/firemon/usage.c
+++ b/src/firemon/usage.c
@@ -31,6 +31,7 @@ static char *help_str =
         "\t--caps - print capabilities configuration for each sandbox.\n\n"
         "\t--cgroup - print control group information for each sandbox.\n\n"
         "\t--cpu - print CPU affinity for each sandbox.\n\n"
+        "\t--debug - print debug messages.\n\n"
         "\t--help, -? - this help screen.\n\n"
         "\t--interface - print network interface information for each sandbox.\n\n"
         "\t--list - list all sandboxes.\n\n"