add option to bind socket to specified interface (e.g. localhost) only

[hmcfgusb] / hmland.c

diff --git a/hmland.c b/hmland.c
index c8781a934f20e185de4d95072cc693784f0ccf81..c3981ab4e912f8f14298f09b84b33e479817793a 100644 (file)
--- a/hmland.c
+++ b/hmland.c
@@ -1,4 +1,4 @@
-/* HM-CFG-LAN emuldation for HM-CFG-USB
+/* HM-CFG-LAN emulation for HM-CFG-USB
  *
  * Copyright (c) 2013 Michael Gernoth <michael@gernoth.net>
  *
@@ -28,6 +28,7 @@
 #include <string.h>
 #include <strings.h>
 #include <poll.h>
+#include <signal.h>
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/socket.h>
@@ -172,15 +173,16 @@ static int parse_part_in(uint8_t **inpos, int inlen, uint8_t **outpos, int outle
        return *outpos - buf_out;
 }
 
-static void hmlan_format_out(uint8_t *buf, int buf_len, void *data)
+static int hmlan_format_out(uint8_t *buf, int buf_len, void *data)
 {
        uint8_t out[1024];
        uint8_t *outpos;
        uint8_t *inpos;
        int fd = *((int*)data);
+       int w;
 
        if (buf_len < 1)
-               return;
+               return 1;
 
        memset(out, 0, sizeof(out));
        outpos = out;
@@ -233,9 +235,16 @@ static void hmlan_format_out(uint8_t *buf, int buf_len, void *data)
                        hexdump(buf, buf_len, "Unknown> ");
                        break;
        }
-       write(fd, out, outpos-out);
        if (debug)
                fprintf(stderr, "LAN < %s\n", out);
+
+       w = write(fd, out, outpos-out);
+       if (w <= 0) {
+               perror("write");
+               return 0;
+       }
+
+       return 1;
 }
 
 static int hmlan_parse_in(int fd, void *data)
@@ -370,8 +379,9 @@ static int comm(int fd_in, int fd_out, int master_socket)
        return 1;
 }
 
-static int socket_server(int port, int daemon)
+static int socket_server(char *iface, int port, int daemon)
 {
+       struct sigaction sact;
        struct sockaddr_in sin;
        int sock;
        int n;
@@ -388,6 +398,14 @@ static int socket_server(int port, int daemon)
                }
        }
 
+       memset(&sact, 0, sizeof(sact));
+       sact.sa_handler = SIG_IGN;
+
+       if (sigaction(SIGPIPE, &sact, NULL) == -1) {
+               perror("sigaction");
+               exit(EXIT_FAILURE);
+       }
+
        impersonate_hmlanif = 1;
 
        sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
@@ -405,7 +423,14 @@ static int socket_server(int port, int daemon)
        memset(&sin, 0, sizeof(sin));
        sin.sin_family = AF_INET;
        sin.sin_port = htons(port);
-       sin.sin_addr.s_addr = htonl(INADDR_ANY);
+       if (!iface) {
+               sin.sin_addr.s_addr = htonl(INADDR_ANY);
+       } else {
+               if (inet_pton(AF_INET, iface, &(sin.sin_addr.s_addr)) != 1) {
+                       perror("inet_ntop");
+                       return EXIT_FAILURE;
+               }
+       }
 
        if (bind(sock, (struct sockaddr*)&sin, sizeof(sin)) == -1) {
                perror("Can't bind socket");
@@ -476,6 +501,7 @@ void hmlan_syntax(char *prog)
        fprintf(stderr, "\t-d\tdaemon mode\n");
        fprintf(stderr, "\t-h\tthis help\n");
        fprintf(stderr, "\t-i\tinteractive mode (connect HM-CFG-USB to terminal)\n");
+       fprintf(stderr, "\t-l ip\tlisten on given IP address only (for example 127.0.0.1)\n");
        fprintf(stderr, "\t-p n\tlisten on port n (default 1000)\n");
        fprintf(stderr, "\t-v\tverbose mode\n");
 
@@ -484,12 +510,13 @@ void hmlan_syntax(char *prog)
 int main(int argc, char **argv)
 {
        int port = 1000;
+       char *iface = NULL;
        int interactive = 0;
        int daemon = 0;
        char *ep;
        int opt;
 
-       while((opt = getopt(argc, argv, "Ddhip:v")) != -1) {
+       while((opt = getopt(argc, argv, "Ddhip:l:v")) != -1) {
                switch (opt) {
                        case 'D':
                                debug = 1;
@@ -508,6 +535,9 @@ int main(int argc, char **argv)
                                        exit(EXIT_FAILURE);
                                }
                                break;
+                       case 'l':
+                               iface = optarg;
+                               break;
                        case 'v':
                                verbose = 1;
                                break;
@@ -524,6 +554,6 @@ int main(int argc, char **argv)
        if (interactive) {
                return interactive_server();
        } else {
-               return socket_server(port, daemon);
+               return socket_server(iface, port, daemon);
        }
 }