Implement support for sending frames with SOCK_RAW

Changes:

    * When associating a promiscuous socket with an interface, rather
      than creating a patty_kiss_tnc object, simply store the socket
      file descriptor and use patty_kiss_frame_send() to send incoming
      or outgoing frames for that interface to the promiscuous socket

    * Add special initialization code in src/sock.c for SOCK_RAW; don't
      allocate any buffers, but instead set a few flags and otherwise
      use 0-initialized defaults

    * Implement handle_sock_raw() in src/server.c to check to see if any
      raw frames are pending, and if so, send them to the associated
      interface if provided by setsockopt()

    * Make patty_ax25_sock_bind_if() only call the function
      patty_ax25_if_add_promisc() only if the socket status is PROMISC;
      this allows support for non-promiscuous sockets used for outbound
      purposes

examples/ax25dump.c

@@ -61,6 +61,8 @@ int main(int argc, char **argv) {
 
     strncpy(ifreq.name, "kiss0", sizeof(ifreq.name));
 
+    ifreq.status = PATTY_AX25_SOCK_PROMISC;
+
     if (patty_client_setsockopt(client, fd, PATTY_AX25_SOCK_IF, &ifreq, sizeof(ifreq)) < 0) {
         fprintf(stderr, "%s: %s: %s\n",
             argv[0], "patty_client_setsockopt()", strerror(errno));

include/patty/ax25/sock.h

@@ -103,6 +103,8 @@ typedef struct _patty_ax25_sock {
 
     patty_ax25_if *iface;
 
+    patty_kiss_tnc *raw;
+
     patty_ax25_addr local,
                     remote,
                     repeaters[PATTY_AX25_MAX_HOPS];

include/patty/client.h

@@ -58,6 +58,7 @@ typedef struct _patty_client_setsockopt_request {
 
 typedef struct _patty_client_setsockopt_if {
     char name[8];
+    int status;
 } patty_client_setsockopt_if;
 
 typedef struct _patty_client_setsockopt_response {

src/if.c

@@ -272,21 +272,15 @@ error_ntop:
 
 int patty_ax25_if_promisc_add(patty_ax25_if *iface,
                               int fd) {
-    patty_kiss_tnc *tnc;
-
     if (patty_dict_get(iface->promisc_fds, (uint32_t)fd)) {
         errno = EEXIST;
 
         goto error_exists;
     }
 
-    if ((tnc = patty_kiss_tnc_new_fd(fd)) == NULL) {
-        goto error_kiss_tnc_new_fd;
-    }
-
     if (patty_dict_set(iface->promisc_fds,
                        (uint32_t)fd,
-                       tnc) == NULL) {
+                       NULL) == NULL) {
         errno = ENOMEM;
 
         goto error_dict_set;
@@ -295,29 +289,13 @@ int patty_ax25_if_promisc_add(patty_ax25_if *iface,
     return 0;
 
 error_dict_set:
-    patty_kiss_tnc_destroy(tnc);
-
-error_kiss_tnc_new_fd:
 error_exists:
     return -1;
 }
 
 int patty_ax25_if_promisc_delete(patty_ax25_if *iface,
                                  int fd) {
-    patty_kiss_tnc *tnc;
-
-    if ((tnc = patty_dict_get(iface->promisc_fds, (uint32_t)fd)) == NULL) {
-        errno = ENOENT;
-
-        goto error_notfound;
-    }
-
-    patty_kiss_tnc_destroy(tnc);
-
     return patty_dict_delete(iface->promisc_fds, (uint32_t)fd);
-
-error_notfound:
-    return -1;
 }
 
 struct promisc_frame {
@@ -329,10 +307,10 @@ struct promisc_frame {
 static int handle_promisc_frame(uint32_t key,
                                 void *value,
                                 void *ctx) {
-    patty_kiss_tnc *tnc = value;
+    int fd = (int)key;
     struct promisc_frame *frame = ctx;
 
-    return patty_kiss_tnc_send(tnc, frame->buf, frame->len, 0);
+    return patty_kiss_frame_send(fd, frame->buf, frame->len, 0);
 }
 
 ssize_t patty_ax25_if_pending(patty_ax25_if *iface) {

src/server.c

@@ -605,6 +605,10 @@ static int server_setsockopt(patty_ax25_server *server,
                 goto error_read;
             }
 
+            if (data.status == PATTY_AX25_SOCK_PROMISC) {
+                sock->status = PATTY_AX25_SOCK_PROMISC;
+            }
+
             if ((iface = patty_ax25_server_get_if(server, data.name)) == NULL) {
                 response.ret = -1;
                 response.eno = ENODEV;
@@ -614,8 +618,6 @@ static int server_setsockopt(patty_ax25_server *server,
 
             patty_ax25_sock_bind_if(sock, iface);
 
-            sock->status = PATTY_AX25_SOCK_PROMISC;
-
             fd_watch(server, sock->fd);
 
             break;
@@ -1732,6 +1734,34 @@ error_io:
     return -1;
 }
 
+static int handle_sock_raw(patty_ax25_server *server,
+                           patty_ax25_sock *sock) {
+    ssize_t len;
+    int port;
+
+    if (!FD_ISSET(sock->fd, &server->fds_r) || sock->iface == NULL) {
+        return 0;
+    }
+
+    if ((len = patty_kiss_tnc_recv(sock->raw,
+                                   sock->iface->tx_buf,
+                                   sock->iface->mtu,
+                                   &port)) < 0) {
+        goto error_io;
+    }
+
+    if (patty_ax25_if_send(sock->iface,
+                           sock->iface->tx_buf,
+                           len) < 0) {
+        goto error_io;
+    }
+
+    return 0;
+
+error_io:
+    return -1;
+}
+
 static int handle_sock(uint32_t key,
                        void *value,
                        void *ctx) {
@@ -1740,6 +1770,10 @@ static int handle_sock(uint32_t key,
 
     ssize_t len;
 
+    if (sock->type == PATTY_AX25_SOCK_RAW) {
+        return handle_sock_raw(server, sock);
+    }
+
     switch (sock->status) {
         case PATTY_AX25_SOCK_PENDING_CONNECT:
             patty_timer_tick(&sock->timer_t1, &server->elapsed);
@@ -1821,15 +1855,14 @@ static int handle_sock(uint32_t key,
         goto done;
     }
 
-    if (sock->type == PATTY_AX25_SOCK_STREAM) {
+    /*
-        /*
+     * NOTE: See AX.25 2.2, Section 6.4.1, "Sending I Frames"
-         * NOTE: See AX.25 2.2, Section 6.4.1, "Sending I Frames"
+     */
-         */
+    if (sock->vs + sock->n_window_tx == sock->vs) {
-        if (sock->vs + sock->n_window_tx == sock->vs) {
+        fd_clear(server, sock->fd);
-            fd_clear(server, sock->fd);
 
-            goto done;
+        return patty_ax25_sock_send_rnr(sock, PATTY_AX25_FRAME_COMMAND, 1);
-        }
+        goto done;
     }
 
     if ((len = read(sock->fd, sock->rx_buf, sock->n_maxlen_rx)) < 0) {
@@ -1850,12 +1883,10 @@ static int handle_sock(uint32_t key,
         goto error_sock_write;
     }
 
-    if (sock->type == PATTY_AX25_SOCK_STREAM) {
+    /*
-        /*
+     * AX.25 v2.2, Section 6.4.1 "Sending I Frames"
-         * AX.25 v2.2, Section 6.4.1 "Sending I Frames"
+     */
-         */
+    patty_timer_start(&sock->timer_t1, sock->n_ack);
-        patty_timer_start(&sock->timer_t1, sock->n_ack);
-    }
 
 done:
     return 0;

src/sock.c

@@ -111,6 +111,29 @@ error_realloc_tx_buf:
     return -1;
 }
 
+static patty_ax25_sock *init_raw(patty_ax25_sock *sock) {
+    if (bind_pty(sock) < 0) {
+        goto error_bind_pty;
+    }
+
+    if ((sock->raw = patty_kiss_tnc_new_fd(sock->fd)) == NULL) {
+        goto error_kiss_tnc_new_fd;
+    }
+
+    sock->proto = PATTY_AX25_PROTO_NONE;
+    sock->type  = PATTY_AX25_SOCK_RAW;
+
+    return sock;
+
+error_kiss_tnc_new_fd:
+    (void)close(sock->fd);
+
+error_bind_pty:
+    free(sock);
+
+    return NULL;
+}
+
 patty_ax25_sock *patty_ax25_sock_new(enum patty_ax25_proto proto,
                                      enum patty_ax25_sock_type type) {
     patty_ax25_sock *sock;
@@ -121,6 +144,10 @@ patty_ax25_sock *patty_ax25_sock_new(enum patty_ax25_proto proto,
 
     memset(sock, '\0', sizeof(*sock));
 
+    if (type == PATTY_AX25_SOCK_RAW) {
+        return init_raw(sock);
+    }
+
     patty_ax25_sock_init(sock);
 
     sock->proto         = proto;
@@ -160,6 +187,10 @@ void patty_ax25_sock_destroy(patty_ax25_sock *sock) {
         close(sock->fd);
     }
 
+    if (sock->raw) {
+        patty_kiss_tnc_destroy(sock->raw);
+    }
+
     free(sock->tx_slots);
     free(sock->rx_buf);
     free(sock->tx_buf);
@@ -315,15 +346,14 @@ char *patty_ax25_sock_pty(patty_ax25_sock *sock) {
 int patty_ax25_sock_bind_if(patty_ax25_sock *sock,
                             patty_ax25_if *iface) {
     sock->iface = iface;
+    sock->flags_classes |= iface->flags_classes;
 
-    if (sock->type == PATTY_AX25_SOCK_RAW) {
+    if (sock->status == PATTY_AX25_SOCK_PROMISC) {
         if (patty_ax25_if_promisc_add(iface, sock->fd) < 0) {
             goto error_if_promisc_add;
         }
     }
 
-    sock->flags_classes |= iface->flags_classes;
-
     return 0;
 
 error_if_promisc_add: