Add IPv6 support (#53)

src/conn.c

@@ -139,26 +139,28 @@ conn_open(void)
 {
   int sd;
   conn_t *newconn;
-  struct sockaddr_in rmt_addr;
+  struct sockaddr_storage rmt_addr;
+  char ipstr[INET6_ADDRSTRLEN];
 
-  if ((sd = sock_accept(server_sd, &rmt_addr, TRUE)) == RC_ERR)
+  if ((sd = sock_accept(server_sd, (struct sockaddr *)&rmt_addr,
+                        sizeof(rmt_addr), TRUE)) == RC_ERR)
   { /* error in conn_accept() */
 #ifdef LOG
     logw(0, "conn_open(): error in accept() (%s)", strerror(errno));
 #endif
     return;
   }
+ inet_ntop(rmt_addr.ss_family, sock_addr((struct sockaddr *)&rmt_addr),
+           ipstr, sizeof(ipstr));
 #ifdef LOG
-  logw(2, "conn_open(): accepting connection from %s",
+  logw(2, "conn_open(): accepting connection from %s", ipstr);
-         inet_ntoa(rmt_addr.sin_addr));
 #endif
   /* compare descriptor of connection with FD_SETSIZE */
   if (sd >= FD_SETSIZE)
   {
 #ifdef LOG
     logw(1, "conn_open(): FD_SETSIZE limit reached,"
-           " connection from %s will be dropped",
+           " connection from %s will be dropped", ipstr);
-           inet_ntoa(rmt_addr.sin_addr));
 #endif
     close(sd);
     return;
@@ -168,8 +170,7 @@ conn_open(void)
   {
 #ifdef LOG
     logw(1, "conn_open(): number of connections limit reached,"
-           " connection from %s will be dropped",
+           " connection from %s will be dropped", ipstr);
-           inet_ntoa(rmt_addr.sin_addr));
 #endif
     close(sd);
     return;
@@ -177,8 +178,7 @@ conn_open(void)
   /* enqueue connection */
   newconn = queue_new_elem(&queue);
   newconn->sd = sd;
-  memcpy((void *) &newconn->sockaddr,
+  memcpy((void *) &newconn->remote_addr, &ipstr, sizeof(ipstr));
-         &rmt_addr, sizeof(struct sockaddr_in));
   state_conn_set(newconn, CONN_HEADER);
 }
 
@@ -192,8 +192,7 @@ conn_close(conn_t *conn)
 {
   conn_t *nextconn;
 #ifdef LOG
-  logw(2, "conn_close(): closing connection from %s",
+  logw(2, "conn_close(): closing connection from %s", conn->remote_addr);
-         inet_ntoa(conn->sockaddr.sin_addr));
 #endif
   /* close socket */
   close(conn->sd);
@@ -535,15 +534,13 @@ conn_loop(void)
             if (curconn->state == CONN_TTY)
             { /* deadlock in CONN_TTY state, make attempt to reinitialize serial port */
 #ifdef LOG
-              logw(0, "conn[%s]: state CONN_TTY deadlock.",
+              logw(0, "conn[%s]: state CONN_TTY deadlock.", curconn->remote_addr);
-                     inet_ntoa(curconn->sockaddr.sin_addr));
 #endif
               tty_reinit();
             }
             /* purge connection */
 #ifdef LOG
-            logw(2, "conn[%s]: timeout, closing connection",
+            logw(2, "conn[%s]: timeout, closing connection", curconn->remote_addr);
-                   inet_ntoa(curconn->sockaddr.sin_addr));
 #endif
             curconn = conn_close(curconn);
             continue;
@@ -789,8 +786,7 @@ conn_loop(void)
                 /* check request function code */
                 unsigned char fc = MB_FRAME(curconn->buf, MB_FCODE);
 #ifdef DEBUG
-                logw(7, "conn[%s]: read request fc %d",
+                logw(7, "conn[%s]: read request fc %d", curconn->remote_addr, fc);
-                     inet_ntoa(curconn->sockaddr.sin_addr), fc);
 #endif
                 switch (fc)
                 {
@@ -849,7 +845,7 @@ conn_loop(void)
                   sprintf(v, "[%2.2x]", curconn->buf[i]);
                   strncat(t, v, 1024-strlen(t));
                 }
-                logw(5, "conn[%s]: request: %s", inet_ntoa(curconn->sockaddr.sin_addr), t);
+                logw(5, "conn[%s]: request: %s", curconn->remote_addr, t);
 #endif
                 state_conn_set(curconn, CONN_TTY);
                 if (tty.state == TTY_READY)

src/conn.h

@@ -104,7 +104,7 @@ typedef struct conn_t
   int sd;               /* socket descriptor */
   int state;            /* current state */
   int timeout;          /* timeout value, secs */
-  struct sockaddr_in sockaddr; /* connection structure */
+  char remote_addr[INET6_ADDRSTRLEN]; /* remote client address */
   int ctr;              /* counter of data in the buffer */
   int read_len;         /* length of modbus frame to read */
   unsigned char buf[HDRSIZE + BUFSIZE];    /* data buffer */

src/sock.c

@@ -58,12 +58,11 @@ sock_set_blkmode(int sd, int blkmode)
  * Return: socket descriptor, otherwise RC_ERR if there some errors
  */
 int
-sock_create(int blkmode)
+sock_create(int blkmode, sa_family_t sa_family)
 {
   int sock;
 
-  if ((sock =
+  if ((sock = socket(sa_family, SOCK_STREAM, IPPROTO_TCP)) == -1)
-         socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
   {
 #ifdef LOG
     logw(0, "sock_create(): unable to create socket (%s)",
@@ -96,17 +95,23 @@ sock_create(int blkmode)
 int
 sock_create_server(char *server_ip, unsigned short server_port, int blkmode)
 {
-  struct sockaddr_in server_sockaddr;
+  struct sockaddr_storage server_sockaddr;
   int sock_opt = 1;
   int server_s;
 
   memset(&server_sockaddr, 0, sizeof(server_sockaddr));
-  server_sockaddr.sin_family = AF_INET; // FIXME IPv6 support
 
   /* parse address to bind socket */
   if (server_ip != NULL)
   {
-    if (inet_aton(server_ip, &server_sockaddr.sin_addr) == 0)
+    /* try first to parse server_ip as IPv6 address, if it fail, try to parse as IPv4 */
+    if (inet_pton(AF_INET6, server_ip,
+                  &(*((struct sockaddr_in6 *)&server_sockaddr)).sin6_addr) != 0)
+      server_sockaddr.ss_family = AF_INET6;
+    else if (inet_pton(AF_INET, server_ip,
+                       &(*((struct sockaddr_in *)&server_sockaddr)).sin_addr) != 0)
+      server_sockaddr.ss_family = AF_INET;
+    else
     {
 #ifdef LOG
       logw(0, "sock_create_server():"
@@ -117,12 +122,23 @@ sock_create_server(char *server_ip, unsigned short server_port, int blkmode)
     }
   }
   else
-    server_sockaddr.sin_addr.s_addr = htonl(INADDR_ANY);
+  {
+    server_sockaddr.ss_family = AF_INET; // TODO AF_INET6/in6addr_any?
+    (*((struct sockaddr_in *)&server_sockaddr)).sin_addr.s_addr = htonl(INADDR_ANY);
+  }
 
-  server_sockaddr.sin_port = htons(server_port);
+  /* parse IP port */
+  switch (server_sockaddr.ss_family) {
+    case AF_INET:
+      (*((struct sockaddr_in *)&server_sockaddr)).sin_port = htons(server_port);
+      break;
+    case AF_INET6:
+      (*((struct sockaddr_in6 *)&server_sockaddr)).sin6_port = htons(server_port);
+      break;
+  }
 
   /* create socket in desired blocking mode */
-  server_s = sock_create(blkmode);
+  server_s = sock_create(blkmode, server_sockaddr.ss_family);
   if (server_s < 0) return server_s;
 
   /* set to close socket on exec() */
@@ -166,7 +182,7 @@ sock_create_server(char *server_ip, unsigned short server_port, int blkmode)
 
   /* bind socket to given address and port */
   if (bind(server_s, (struct sockaddr *)&server_sockaddr,
-           sizeof(server_sockaddr)) == -1)
+           sa_len((struct sockaddr *)&server_sockaddr)) == -1)
   {
 #ifdef LOG
     logw(0, "sock_create_server():"
@@ -198,13 +214,11 @@ sock_create_server(char *server_ip, unsigned short server_port, int blkmode)
  *         RMT_ADDR - ptr to connection info structure
  */
 int
-sock_accept(int server_sd, struct sockaddr_in *rmt_addr, int blkmode)
+sock_accept(int server_sd, struct sockaddr *rmt_addr, socklen_t rmt_len, int blkmode)
 {
   int sd, sock_opt = SOCKBUFSIZE;
-  int rmt_len = sizeof(struct sockaddr_in);
 
-  sd = accept(server_sd, (struct sockaddr *) rmt_addr,
+  sd = accept(server_sd, rmt_addr, &rmt_len);
-              (socklen_t *) &rmt_len);
   if (sd == -1)
   {
     if (errno != EAGAIN && errno != EWOULDBLOCK)
@@ -241,3 +255,17 @@ sock_accept(int server_sd, struct sockaddr_in *rmt_addr, int blkmode)
   }
   return sd;
 }
+
+/*
+ * Return reference to socket address structure according to its family (AF_INET/AF_INET6)
+ */
+void *
+sock_addr(struct sockaddr *sa)
+{
+  if (sa->sa_family == AF_INET)
+  {
+    return &(((struct sockaddr_in*)sa)->sin_addr);
+  }
+
+  return &(((struct sockaddr_in6*)sa)->sin6_addr);
+}

src/sock.h

@@ -44,11 +44,13 @@
 /* Socket buffers size */
 #define SOCKBUFSIZE 512
 
+#define sa_len(sa_ptr) ((sa_ptr)->sa_family == AF_INET \
+    ? sizeof (struct sockaddr_in) : sizeof (struct sockaddr_in6))
+
 int sock_set_blkmode(int sd, int blkmode);
-int sock_create(int blkmode);
+int sock_create(int blkmode, sa_family_t sa_family);
-int sock_create_server(char *server_ip,
+int sock_create_server(char *server_ip, unsigned short server_port, int blkmode);
-  unsigned short server_port, int blkmode);
+int sock_accept(int server_sd, struct sockaddr *rmt_addr, socklen_t rmt_len, int blkmode);
-int sock_accept(int server_sd,
+void *sock_addr(struct sockaddr *sa);
-  struct sockaddr_in *rmt_addr, int blkmode);
 
 #endif

src/state.c

@@ -76,47 +76,40 @@ state_conn_set(conn_t *conn, int state)
       conn->ctr = 0;
       conn->read_len = HDRSIZE;
 #ifdef DEBUG
-      logw(5, "conn[%s]: state now is CONN_HEADER",
+      logw(5, "conn[%s]: state now is CONN_HEADER", conn->remote_addr);
-             inet_ntoa(conn->sockaddr.sin_addr));
 #endif
       break;
     case CONN_RQST_FUNC:
       conn->read_len = HDRSIZE + MB_FRAME(conn->buf, MB_LENGTH_L);
 #ifdef DEBUG
-      logw(5, "conn[%s]: state now is CONN_RQST_FUNC",
+      logw(5, "conn[%s]: state now is CONN_RQST_FUNC", conn->remote_addr);
-             inet_ntoa(conn->sockaddr.sin_addr));
 #endif
     break;
     case CONN_RQST_NVAL:
 #ifdef DEBUG
-      logw(5, "conn[%s]: state now is CONN_RQST_NVAL",
+      logw(5, "conn[%s]: state now is CONN_RQST_NVAL", conn->remote_addr);
-             inet_ntoa(conn->sockaddr.sin_addr));
 #endif
     break;
     case CONN_RQST_TAIL:
 #ifdef DEBUG
-      logw(5, "conn[%s]: state now is CONN_RQST_TAIL",
+      logw(5, "conn[%s]: state now is CONN_RQST_TAIL", conn->remote_addr);
-             inet_ntoa(conn->sockaddr.sin_addr));
 #endif
     break;
     case CONN_TTY:
 #ifdef DEBUG
-      logw(5, "conn[%s]: state now is CONN_TTY",
+      logw(5, "conn[%s]: state now is CONN_TTY", conn->remote_addr);
-             inet_ntoa(conn->sockaddr.sin_addr));
 #endif
       break;
     case CONN_RESP:
       conn->ctr = 0;
 #ifdef DEBUG
-      logw(5, "conn[%s]: state now is CONN_RESP",
+      logw(5, "conn[%s]: state now is CONN_RESP", conn->remote_addr);
-             inet_ntoa(conn->sockaddr.sin_addr));
 #endif
       break;
     default:
       /* unknown state, exiting */
 #ifdef DEBUG
-      logw(5, "conn_set_state([%s]) - invalid state (%d)",
+      logw(5, "conn_set_state([%s]) - invalid state (%d)", conn->remote_addr, state);
-             inet_ntoa(conn->sockaddr.sin_addr), state);
 #endif
       exit (-1);
   }