pmlag

commit dff2c19a0738b02f3024b07446d952045f75fbad
parent 120ec87fd77624a5c99f6318ac2599dbf0b91261
Author: Robin Bron <robin@finwo.nl>
Date:   Wed, 27 Apr 2022 21:33:47 +0200

Separated raw socket creation from main

Diffstat:
M
src/main.c
 | 
33
++++-----------------------------
A
src/socket.c
 | 
57
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
src/socket.h
 | 
14
++++++++++++++

3 files changed, 75 insertions(+), 29 deletions(-)
diff --git a/src/main.c b/src/main.c
@@ -10,6 +10,8 @@
 
 #include <linux/if_packet.h>
 
+#include "socket.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -18,34 +20,7 @@ extern "C" {
 #define ERR_NAME "pmlag"
 
 int main(int argc, char **argv) {
-
-  // Open socket
-  int sockfd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
-  if (sockfd < 0) {
-    perror(ERR_NAME ": socket");
-    exit(EXIT_FAILURE);
-  }
-
-  struct sockaddr_ll sll;
-  struct ifreq ifr;
-  bzero(&sll, sizeof(sll));
-  bzero(&ifr, sizeof(ifr));
-
-  // Get interface index
-  strncpy((char *)ifr.ifr_name, INTERFACE, IFNAMSIZ);
-  if ((ioctl(sockfd, SIOCGIFINDEX, &ifr)) == -1) {
-    perror(ERR_NAME ": Error getting interface index");
-    exit(EXIT_FAILURE);
-  }
-
-  // Bind socket to interface
-  sll.sll_family   = AF_PACKET;
-  sll.sll_ifindex  = ifr.ifr_ifindex;
-  sll.sll_protocol = htons(ETH_P_ALL);
-  if((bind(sockfd, (struct sockaddr *)&sll, sizeof(sll))) == -1) {
-    perror(ERR_NAME ": Error binding raw socket to interface");
-    exit(EXIT_FAILURE);
-  }
+  int sockfd = sockraw_open(INTERFACE);
 
   // Prepare ingress buffer
   int buflen;
@@ -98,7 +73,7 @@ int main(int argc, char **argv) {
     printf("\n");
   }
 
-  return 42;
+  return 0;
 }
 
 #ifdef __cplusplus
diff --git a/src/socket.c b/src/socket.c
@@ -0,0 +1,57 @@
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <arpa/inet.h>
+#include <net/ethernet.h>
+#include <net/if.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include <linux/if_packet.h>
+
+int sockraw_open(char * ifname) {
+
+  // Open socket
+  int sockfd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
+  if (sockfd < 0) {
+    perror("Error opening socket");
+    close(sockfd);
+    return -1;
+  }
+
+  struct sockaddr_ll sll;
+  struct ifreq ifr;
+  bzero(&sll, sizeof(sll));
+  bzero(&ifr, sizeof(ifr));
+
+  // Get interface index
+  strncpy((char *)ifr.ifr_name, ifname, IFNAMSIZ);
+  if ((ioctl(sockfd, SIOCGIFINDEX, &ifr)) == -1) {
+    perror("Error getting interface index");
+    close(sockfd);
+    return -1;
+  }
+
+  // Bind socket to interface
+  sll.sll_family   = AF_PACKET;
+  sll.sll_ifindex  = ifr.ifr_ifindex;
+  sll.sll_protocol = htons(ETH_P_ALL);
+  if((bind(sockfd, (struct sockaddr *)&sll, sizeof(sll))) == -1) {
+    perror("Error binding raw socket to interface");
+    close(sockfd);
+    return -1;
+  }
+
+  // Return the prepared socket
+  return sockfd;
+}
+
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
diff --git a/src/socket.h b/src/socket.h
@@ -0,0 +1,14 @@
+#ifndef __PMLAG_SOCKET_H__
+#define __PMLAG_SOCKET_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int sockraw_open(char * ifname);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif // __PMLAG_SOCKET_H__