increase socket buffer size for firemon, bug #2700

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;

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");

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;
  }
  }

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"

src/man/firemon.txt

@@ -25,6 +25,9 @@ Print control group information for each sandbox.
 \fB\-\-cpu
 Print CPU affinity for each sandbox.
 .TP
+\fB\-\-debug
+Print debug messages
+.TP
 \fB\-?\fR, \fB\-\-help\fR
 Print options end exit.
 .TP