From 628edceba5f1485ef7c4ef30fba93b4c0c0dd955 Mon Sep 17 00:00:00 2001
From: Craig Small <csmall@enc.com.au>
Date: Tue, 10 Apr 2001 01:57:46 +0000
Subject: Initial revision

---
 ax25mond/ax25mond.c | 377 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 377 insertions(+)
 create mode 100644 ax25mond/ax25mond.c

(limited to 'ax25mond/ax25mond.c')

diff --git a/ax25mond/ax25mond.c b/ax25mond/ax25mond.c
new file mode 100644
index 0000000..58a932a
--- /dev/null
+++ b/ax25mond/ax25mond.c
@@ -0,0 +1,377 @@
+/*
+ *  ax25mond.c - Wrapper for offering AX.25 traffic to non-root processes
+ *
+ *  Copyright (C) 1998-1999 Johann Hanne, DH3MB. All rights reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/*--------------------------------------------------------------------------*/
+
+#define VERSION "1.0"
+#define CONFFILE "/etc/ax25/ax25mond.conf"
+#define MAX_SOCKETS  5
+#define MAX_CONNECTS 50
+
+/*--------------------------------------------------------------------------*/
+
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <netdb.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <sys/time.h>
+#include <sys/un.h>
+#include <sys/socket.h>
+#include <sys/fcntl.h>
+#include <sys/signal.h>
+#include <sys/ioctl.h>
+#include <net/if.h>
+#include <netinet/if_ether.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+// For older kernels
+#ifndef PF_PACKET
+  #define PF_PACKET PF_INET
+#endif
+
+/*--------------------------------------------------------------------------*/
+
+static union {
+  struct sockaddr sa;
+  struct sockaddr_in si;
+  struct sockaddr_un su;
+} addr;
+
+/*--------------------------------------------------------------------------*/
+
+int sock_list[MAX_SOCKETS];
+char sock_monmode[MAX_SOCKETS];
+char sock_filename[MAX_SOCKETS][100];
+int sock_num=0;
+int conn_list[MAX_CONNECTS];
+struct sockaddr conn_addr[MAX_CONNECTS];
+int conn_addrlen[MAX_CONNECTS];
+char conn_monmode[MAX_CONNECTS];
+int conn_num=0;
+int highest_sock_fd;
+int end=0;
+
+/*--------------------------------------------------------------------------*/
+
+/* from buildsaddr.c */
+struct sockaddr *build_sockaddr(const char *name, int *addrlen)
+{ char *host_name;
+  char *serv_name;
+  char buf[1024];
+
+  memset((char *) &addr, 0, sizeof(addr));
+  *addrlen=0;
+
+  host_name=strcpy(buf, name);
+  serv_name=strchr(buf, ':');
+  if(!serv_name)
+    return 0;
+  *serv_name++=0;
+  if(!*host_name || !*serv_name)
+    return 0;
+
+  if(!strcmp(host_name, "local") || !strcmp(host_name, "unix")) {
+    addr.su.sun_family=AF_UNIX;
+    *addr.su.sun_path=0;
+    strcat(addr.su.sun_path, serv_name);
+    *addrlen=sizeof(struct sockaddr_un);
+    return &addr.sa;
+  }
+
+  addr.si.sin_family=AF_INET;
+
+  if(!strcmp(host_name, "*")) {
+    addr.si.sin_addr.s_addr=INADDR_ANY;
+  } else if(!strcmp(host_name, "loopback")) {
+    addr.si.sin_addr.s_addr=inet_addr("127.0.0.1");
+  } else if((addr.si.sin_addr.s_addr=inet_addr(host_name))==-1L) {
+    struct hostent *hp=gethostbyname(host_name);
+    endhostent();
+    if(!hp)
+      return 0;
+    addr.si.sin_addr.s_addr=((struct in_addr *) (hp->h_addr))->s_addr;
+  }
+
+  if(isdigit(*serv_name & 0xff)) {
+    addr.si.sin_port=htons(atoi(serv_name));
+  } else {
+    struct servent *sp=getservbyname(serv_name, (char *) 0);
+    endservent();
+    if(!sp)
+      return 0;
+    addr.si.sin_port=sp->s_port;
+  }
+
+  *addrlen=sizeof(struct sockaddr_in);
+  return &addr.sa;
+}
+
+/*--------------------------------------------------------------------------*/
+
+void add_socket(char *sockname, char monmode) {
+  struct sockaddr *saddr;
+  int saddrlen;
+
+  if(sock_num==MAX_SOCKETS-1) {
+    fprintf(stderr, "WARNING: Too many sockets defined - only %d are "
+            "allowed\n", MAX_SOCKETS);
+    return;
+  }
+
+  if(!(saddr=build_sockaddr(sockname,&saddrlen))) {
+    fprintf(stderr, "WARNING: Invalid socket name: \"%s\"\n", sockname);
+    return;
+  }
+
+  if(saddr->sa_family==AF_UNIX)
+    strcpy(sock_filename[sock_num], strchr(sockname, ':')+1);
+  else
+    sock_filename[sock_num][0]=0;
+
+  if((sock_list[sock_num]=socket(saddr->sa_family,SOCK_STREAM,0))<0) {
+    fprintf(stderr, "WARNING: Error opening socket \"%s\": %s\n",
+           sockname, strerror(errno));
+    return;
+  }
+
+  if(bind(sock_list[sock_num],saddr,saddrlen)<0) {
+    fprintf(stderr, "WARNING: Error binding socket \"%s\": %s\n",
+            sockname, strerror(errno));
+    return;
+  }
+
+  if(listen(sock_list[sock_num], 5)<0) {
+    fprintf(stderr, "WARNING: Error listening on socket \"%s\": %s\n",
+           sockname, strerror(errno));
+    return;
+  }
+
+  fcntl(sock_list[sock_num],F_SETFL,O_NONBLOCK);
+
+  if(sock_list[sock_num] > highest_sock_fd)
+    highest_sock_fd=sock_list[sock_num];
+
+  sock_monmode[sock_num]=monmode;
+  sock_num++;
+}
+
+/*--------------------------------------------------------------------------*/
+
+void close_sockets() {
+  int i;
+  
+  for(i=0;i<sock_num;i++) {
+    close(sock_list[i]);
+
+    if(sock_filename[i][0])
+      unlink(sock_filename[i]);
+  }
+}
+
+/*--------------------------------------------------------------------------*/
+
+void quit_handler(int dummy) {
+  end=1;
+}
+
+/*--------------------------------------------------------------------------*/
+
+int main(int argc, char *argv[]) {
+  fd_set monavail;
+  int monrx_fd, monrxtx_fd;
+  struct sockaddr monfrom;
+  int monfromlen;
+  fd_set conn_request;
+  struct timeval tv;
+  char buf[500];
+  int size;
+  int i;
+  struct ifreq ifr;
+  FILE *conffile;
+  char confline[100];
+  char *mode;
+  char *sockname;
+
+  if(argc>1) {
+    if(argc==2 &&
+       (strcmp(argv[1],"-v")==0 || strcmp(argv[1],"--version")==0)) {
+      printf("%s: Version " VERSION "\n\n", argv[0]);
+      printf("Copyright (C) 1998-1999 Johann Hanne, DH3MB. All rights reserved.\n"
+             "This program is free software; you can redistribute it and/or modify\n"
+             "it under the terms of the GNU General Public License as published by\n"
+             "the Free Software Foundation; either version 2 of the License, or\n"
+             "(at your option) any later version.\n\n"
+             "This program is distributed in the hope that it will be useful,\n"
+             "but WITHOUT ANY WARRANTY; without even the implied warranty of\n"
+             "MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\n");
+      exit(1);
+    } else {
+      printf("Usage: %s [-v|--version]\n", argv[0]);
+      exit(0);
+    }
+  }
+
+  // At first, read the configuration file
+  if(!(conffile=fopen(CONFFILE, "r"))) {
+    fprintf(stderr, "Unable to open " CONFFILE ".\n");
+    exit(1);
+  }
+  while(fgets(confline, 100, conffile)) {
+    if(confline[0]=='#') // Comment
+      continue;
+
+    confline[strlen(confline)-1]=0; // Cut the LF
+
+    if(!(sockname=strchr(confline, ' '))) {
+      fprintf(stderr, "WARNING: The following configuration line includes "
+                       "one or more errors:\n%s\n", confline);
+      continue;
+    }
+
+    *(sockname++)=0;
+    mode=confline;
+    if(strcasecmp(mode, "RX")==0)
+      add_socket(sockname, 0);
+    else if(strcasecmp(mode, "RXTX")==0)
+      add_socket(sockname, 1);
+    else
+      fprintf(stderr, "WARNING: Mode \"%s\" not supported\n", mode);
+
+  }
+  fclose(conffile);
+
+  if(sock_num==0) {
+    fprintf(stderr, "FATAL: No usable socket found\n");
+    exit(1);
+  }
+
+  // Fork into background
+  if(fork())
+    exit(0);
+
+  // Close stdout, stderr and stdin
+  fclose(stdout);
+  fclose(stderr);
+  fclose(stdin);
+
+  // Set some signal handlers
+  signal(SIGPIPE, SIG_IGN);
+  signal(SIGTERM, quit_handler);
+
+  openlog("ax25mond", LOG_PID, LOG_DAEMON);
+
+  // Open AX.25 socket for monitoring RX traffic only
+  if((monrx_fd=socket(PF_PACKET,SOCK_PACKET,htons(ETH_P_AX25)))<0) {
+    syslog(LOG_ERR, "Error opening monitor socket: %s\n",strerror(errno));
+    exit(1);
+  }
+  fcntl(monrx_fd,F_SETFL,O_NONBLOCK);
+
+  // Open AX.25 socket for monitoring RX and TX traffic
+  if((monrxtx_fd=socket(PF_PACKET,SOCK_PACKET,htons(ETH_P_ALL)))<0) {
+    syslog(LOG_ERR, "Error opening monitor socket: %s\n",strerror(errno));
+    exit(1);
+  }
+  fcntl(monrxtx_fd,F_SETFL,O_NONBLOCK);
+
+  while(!end) {
+
+    // Look for incoming connects on all open sockets
+    FD_ZERO(&conn_request);
+    for(i=0;i<sock_num;i++)
+      FD_SET(sock_list[i], &conn_request);
+    tv.tv_sec=0;
+    tv.tv_usec=0;
+    select(highest_sock_fd+1, &conn_request, 0, 0, &tv);
+    for(i=0;i<sock_num;i++)
+      if(FD_ISSET(sock_list[i], &conn_request)) {
+        conn_list[conn_num]=accept(sock_list[i],
+                                   &conn_addr[conn_num],
+                                   &conn_addrlen[conn_num]);
+        conn_monmode[conn_num]=sock_monmode[i];
+        conn_num++;
+      }
+
+    // Check if there is new data on the RX-only monitor socket
+    FD_ZERO(&monavail);
+    FD_SET(monrx_fd,&monavail);
+    tv.tv_sec=0;
+    tv.tv_usec=10;
+    select(monrx_fd+1, &monavail, 0, 0, &tv);
+    if(FD_ISSET(monrx_fd,&monavail)) {
+      monfromlen=sizeof(monfrom);
+      size=recvfrom(monrx_fd,buf,sizeof(buf),0,&monfrom,&monfromlen);
+      // Send the packet to all connected sockets
+      for(i=0;i<conn_num;i++) {
+        if(conn_monmode[i]==0)
+          if(send(conn_list[i],buf,size,0)<0)
+            if(errno!=EAGAIN) {
+              syslog(LOG_ERR, "Error sending monitor data: %s\n",
+                     strerror(errno));
+              close(conn_list[i]);
+              conn_list[i]=conn_list[conn_num-1];
+              conn_num--;
+            }
+      }
+    }
+
+    // Check if there is new data on the RX+TX monitor socket
+    FD_ZERO(&monavail);
+    FD_SET(monrxtx_fd,&monavail);
+    tv.tv_sec=0;
+    tv.tv_usec=10;
+    select(monrxtx_fd+1, &monavail, 0, 0, &tv);
+    if(FD_ISSET(monrxtx_fd,&monavail)) {
+      monfromlen=sizeof(monfrom);
+      size=recvfrom(monrxtx_fd,buf,sizeof(buf),0,&monfrom,&monfromlen);
+      // Check, if we have received a AX.25-packet
+      strcpy(ifr.ifr_name,monfrom.sa_data);
+      ioctl(monrxtx_fd,SIOCGIFHWADDR,&ifr);
+      if (ifr.ifr_hwaddr.sa_family==AF_AX25)
+        // Send the packet to all connected sockets
+        for(i=0;i<conn_num;i++) {
+          if(conn_monmode[i]==1)
+            if(send(conn_list[i],buf,size,0)<0)
+              if(errno!=EAGAIN) {
+                syslog(LOG_ERR, "Error sending monitor data: %s\n",
+                       strerror(errno));
+                close(conn_list[i]);
+                conn_list[i]=conn_list[conn_num-1];
+                conn_num--;
+              }
+        }
+    }
+
+  }
+
+  for(i=0;i<conn_num;i++)
+    close(conn_list[i]);
+  close_sockets();
+  close(monrx_fd);
+  close(monrxtx_fd);
+  closelog();
+  return 0;
+}
-- 
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