NATMap: Add per-socket TCP congestion control support.

Author: heiher

README.md

@@ -65,6 +65,7 @@ Bind options:
                      - <port>-<port>: sequential allocation within the range
 
 Forward options:
+ -C <congestion>     TCP congestion control algorithm
  -T <timeout>        port forwarding timeout in seconds
  -t <address>        domain name or address of forward target
  -p <port>           port number of forward target (0: use public port)

src/hev-conf.c

@@ -38,6 +38,7 @@ static const char *path;
 static const char *baddr;
 static const char *taddr;
 static const char *tport;
+static const char *ttcca;
 static const char *iface;
 
 const char *
@@ -68,6 +69,7 @@ hev_conf_help (void)
         "                     - <port>-<port>: sequential allocation within the range\n"
         "\n"
         "Forward options:\n"
+        " -C <congestion>     TCP congestion control algorithm\n"
         " -T <timeout>        port forwarding timeout in seconds\n"
         " -t <address>        domain name or address of forward target\n"
         " -p <port>           port number of forward target (0: use public port)\n";
@@ -82,7 +84,7 @@ hev_conf_init (int argc, char *argv[])
     int opt;
     char c;
 
-    while ((opt = getopt (argc, argv, "46udk:c:s:h:e:f:b:T:t:p:i:")) != -1) {
+    while ((opt = getopt (argc, argv, "46udk:c:s:h:e:f:b:C:T:t:p:i:")) != -1) {
         switch (opt) {
         case '4':
             type = AF_INET;
@@ -117,6 +119,9 @@ hev_conf_init (int argc, char *argv[])
         case 'b':
             sscanf (optarg, "%u%c%u", &bport[0], &c, &bport[1]);
             break;
+        case 'C':
+            ttcca = optarg;
+            break;
         case 'T':
             tmsec = strtoul (optarg, NULL, 10) * 1000;
             break;
@@ -279,6 +284,12 @@ hev_conf_tmsec (void)
     return tmsec;
 }
 
+const char *
+hev_conf_ttcca (void)
+{
+    return ttcca;
+}
+
 const char *
 hev_conf_mport (int port)
 {

src/hev-conf.h

@@ -147,6 +147,15 @@ const char *hev_conf_tport (void);
  */
 int hev_conf_tmsec (void);
 
+/**
+ * hev_conf_ttcca:
+ *
+ * Get TCP congestion control algorithm for port forwarding.
+ *
+ * Returns: returns string.
+ */
+const char *hev_conf_ttcca (void);
+
 /**
  * hev_conf_mport:
  * @port: port number

src/hev-misc.c

@@ -16,7 +16,9 @@
 #include <sys/socket.h>
 
 #if defined(__linux__)
+#include <netinet/in.h>
 #include <sys/syscall.h>
+#include <netinet/tcp.h>
 #endif
 
 #include "hev-misc.h"
@@ -237,6 +239,16 @@ hev_reuse_port (const char *port)
     return result;
 }
 
+int
+hev_tcp_cca (int fd, const char *algo)
+{
+#ifdef __linux__
+    return setsockopt (fd, IPPROTO_TCP, TCP_CONGESTION, algo, strlen (algo));
+#else
+    return 0;
+#endif
+}
+
 int
 hev_run_daemon (void)
 {

src/hev-misc.h

@@ -57,6 +57,16 @@ int hev_io_yielder (HevTaskYieldType type, void *data);
  */
 int hev_reuse_port (const char *port);
 
+/**
+ * hev_tcp_cca:
+ * @algo: congestion control algorithm
+ *
+ * Set the TCP congestion control algorithm.
+ *
+ * Returns: returns zero on successful, otherwise returns -1.
+ */
+int hev_tcp_cca (int fd, const char *algo);
+
 /**
  * hev_run_daemon:
  *

src/hev-tfwd.c

@@ -39,6 +39,7 @@ client_task_entry (void *data)
     HevTask *task = hev_task_self ();
     const char *addr;
     const char *port;
+    const char *tcca;
     int timeout;
     int mode;
     int sfd;
@@ -48,6 +49,7 @@ client_task_entry (void *data)
     mode = hev_conf_mode ();
     addr = hev_conf_taddr ();
     port = hev_conf_tport ();
+    tcca = hev_conf_ttcca ();
     timeout = hev_conf_tmsec ();
 
     if (strtoul (port, NULL, 10) == 0)
@@ -60,6 +62,11 @@ client_task_entry (void *data)
         return;
     }
 
+    if (tcca) {
+        if (hev_tcp_cca (sfd, tcca) < 0)
+            LOGV (W, "%s", "TCP congeston control failed.");
+    }
+
     hev_task_add_fd (task, sfd, POLLIN | POLLOUT);
     hev_task_io_splice (sfd, sfd, dfd, dfd, 8192, io_yielder, &timeout);