From e55f87137c6ea58547cfbe060a8dacb5f833e368 Mon Sep 17 00:00:00 2001
From: Ivan Gankevich <i.gankevich@spbu.ru>
Date: Thu, 13 Apr 2023 15:29:24 +0200
Subject: [PATCH] Add `-bind_to_device` option.

---
 include/sipp.hpp   |  2 ++
 include/socket.hpp |  3 +++
 src/sipp.cpp       |  1 +
 src/socket.cpp     | 13 +++++++++++++
 4 files changed, 19 insertions(+)

diff --git a/include/sipp.hpp b/include/sipp.hpp
index 1faf581f..738fc851 100644
--- a/include/sipp.hpp
+++ b/include/sipp.hpp
@@ -322,6 +322,8 @@ MAYBE_EXTERN const char       * tls_crl_name            DEFVAL(DEFAULT_TLS_CRL);
 MAYBE_EXTERN double             tls_version             DEFVAL(0.0);
 #endif
 
+MAYBE_EXTERN const char       * bind_to_device_name     DEFVAL(NULL);
+
 MAYBE_EXTERN char*              scenario_file           DEFVAL(NULL);
 MAYBE_EXTERN char*              scenario_path           DEFVAL(NULL);
 
diff --git a/include/socket.hpp b/include/socket.hpp
index 01dc9f93..1afa3471 100644
--- a/include/socket.hpp
+++ b/include/socket.hpp
@@ -88,6 +88,9 @@ class SIPpSocket {
     // Have we read a message from this socket?
     bool message_ready() { return ss_msglen > 0; };
 
+    // Bind to specific network device.
+    int bind_to_device(const char* device_name);
+
     static void pollset_process(int wait);
 
     int ss_count;           /* How many users are there of this socket? */
diff --git a/src/sipp.cpp b/src/sipp.cpp
index 84c42d40..18394e1d 100644
--- a/src/sipp.cpp
+++ b/src/sipp.cpp
@@ -167,6 +167,7 @@ struct sipp_option options_table[] = {
     {"i", "Set the local IP address for 'Contact:','Via:', and 'From:' headers. Default is primary host IP address.\n", SIPP_OPTION_IP, local_ip, 1},
     {"p", "Set the local port number.  Default is a random free port chosen by the system.", SIPP_OPTION_INT, &user_port, 1},
     {"bind_local", "Bind socket to local IP address, i.e. the local IP address is used as the source IP address.  If SIPp runs in server mode it will only listen on the local IP address instead of all IP addresses.", SIPP_OPTION_SETFLAG, &bind_local, 1},
+    {"bind_to_device", "Bind socket to the specified network device. Requires superuser permissions.", SIPP_OPTION_STRING, &bind_to_device_name, 1},
     {"ci", "Set the local control IP address", SIPP_OPTION_IP, control_ip, 1},
     {"cp", "Set the local control port number. Default is 8888.", SIPP_OPTION_INT, &control_port, 1},
     {"max_socket", "Set the max number of sockets to open simultaneously. This option is significant if you use one socket per call. Once this limit is reached, traffic is distributed over the sockets already opened. Default value is 50000", SIPP_OPTION_MAX_SOCKET, NULL, 1},
diff --git a/src/socket.cpp b/src/socket.cpp
index c83b2456..0b43b9be 100644
--- a/src/socket.cpp
+++ b/src/socket.cpp
@@ -1651,6 +1651,14 @@ int SIPpSocket::reconnect()
     return connect();
 }
 
+int SIPpSocket::bind_to_device(const char* device_name) {
+    if (setsockopt(this->ss_fd, SOL_SOCKET, SO_BINDTODEVICE,
+                   device_name, strlen(device_name)) == -1) {
+        ERROR_NO("setsockopt(SO_BINDTODEVICE) failed");
+    }
+    return 0;
+}
+
 
 /*************************** I/O functions ***************************/
 
@@ -2471,6 +2479,11 @@ int open_connections()
 
     sipp_customize_socket(main_socket);
 
+    /* Bind to the device if any. */
+    if (bind_to_device_name) {
+        main_socket->bind_to_device(bind_to_device_name);
+    }
+
     /* Trying to bind local port */
     char peripaddr[256];
     if (!user_port) {