Introduce recv timeout controlled by '-T' option in http.c

This should prevent a DDoS attack where attacker and keeps the connection open
but send no data.

1 files changed, 25 insertions, 4 deletions

diff --git a/src/c/http.c b/src/c/http.c
index 2a8b7e94..9651a216 100644
--- a/src/c/http.c
+++ b/src/c/http.c
@@ -116,7 +116,7 @@ static void *worker(void *data) {
         r = recv(sock, back, buf_size - 1 - (back - buf), 0);
 
         if (r < 0) {
-          qfprintf(stderr, "Recv failed while receiving header\n");
+          qfprintf(stderr, "Recv failed while receiving header, retcode %d errno %m\n", r);
           close(sock);
           sock = 0;
           break;
@@ -173,7 +173,7 @@ static void *worker(void *data) {
             r = recv(sock, back, buf_size - 1 - (back - buf), 0);
 
             if (r < 0) {
-              qfprintf(stderr, "Recv failed\n");
+              qfprintf(stderr, "Recv failed while receiving content, retcode %d errno %m\n", r);
               close(sock);
               sock = 0;
               goto done;
@@ -312,7 +312,7 @@ static void *worker(void *data) {
 }
 
 static void help(char *cmd) {
-  printf("Usage: %s [-p <port>] [-a <IP address>] [-t <thread count>] [-k] [-q]\nThe '-k' option turns on HTTP keepalive.\nThe '-q' option turns off some chatter on stdout.\n", cmd);
+  printf("Usage: %s [-p <port>] [-a <IP address>] [-t <thread count>] [-k] [-q] [-T SEC]\nThe '-k' option turns on HTTP keepalive.\nThe '-q' option turns off some chatter on stdout.\nThe -T option sets socket recv timeout (0 disables timeout, default is 5 sec)", cmd);
 }
 
 static void sigint(int signum) {
@@ -327,6 +327,7 @@ int main(int argc, char *argv[]) {
   struct sockaddr_in their_addr; // connector's address information
   socklen_t sin_size;
   int yes = 1, uw_port = 8080, nthreads = 1, i, *names, opt;
+  int recv_timeout_sec = 5;
  
   signal(SIGINT, sigint);
   signal(SIGPIPE, SIG_IGN); 
@@ -334,7 +335,7 @@ int main(int argc, char *argv[]) {
   my_addr.sin_addr.s_addr = INADDR_ANY; // auto-fill with my IP
   memset(my_addr.sin_zero, '\0', sizeof my_addr.sin_zero);
 
-  while ((opt = getopt(argc, argv, "hp:a:t:kq")) != -1) {
+  while ((opt = getopt(argc, argv, "hp:a:t:kqT:")) != -1) {
     switch (opt) {
     case '?':
       fprintf(stderr, "Unknown command-line option\n");
@@ -375,6 +376,15 @@ int main(int argc, char *argv[]) {
       keepalive = 1;
       break;
 
+    case 'T':
+      recv_timeout_sec = atoi(optarg);
+      if (recv_timeout_sec < 0) {
+        fprintf(stderr, "Invalid recv timeout\n");
+        help(argv[0]);
+        return 1;
+      }
+      break;
+
     case 'q':
       quiet = 1;
       break;
@@ -453,6 +463,17 @@ int main(int argc, char *argv[]) {
         setsockopt(new_fd, IPPROTO_TCP, TCP_NODELAY, (char *) &flag, sizeof(int));
       }
 
+      if(recv_timeout_sec>0) {
+        int ret;
+        struct timeval tv;
+        memset(&tv, 0, sizeof(struct timeval));
+        tv.tv_sec = recv_timeout_sec;
+        ret = setsockopt(new_fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&tv, sizeof(struct timeval));
+        if(ret != 0) {
+          qfprintf(stderr, "Timeout setting failed, errcode %d errno '%m'\n", ret);
+        }
+      }
+
       uw_enqueue(new_fd);
     }
   }