Implement interface resetting

Changes:

    * Implement patty_ax25_if_reset() to allow pattyd(8) to attempt to
      reset the network interface in the event of an I/O error

    * Move existing link resetting code in src/aprs_is.c to
      patty_ax25_aprs_is_reset(); allow src/server.c to call this rather
      than within src/aprs_is.c itself

    * Implement patty_kiss_tnc_reset(); this simply sets errno to ENOSYS
      and returns -1 for the time being

include/patty/ax25/aprs_is.h

@@ -37,6 +37,8 @@ int patty_ax25_aprs_is_fd(patty_ax25_aprs_is *aprs);
 
 int patty_ax25_aprs_is_ready(patty_ax25_aprs_is *aprs, fd_set *fds);
 
+int patty_ax25_aprs_is_reset(patty_ax25_aprs_is *aprs);
+
 ssize_t patty_ax25_aprs_is_fill(patty_ax25_aprs_is *aprs);
 
 ssize_t patty_ax25_aprs_is_drain(patty_ax25_aprs_is *aprs,

include/patty/ax25/if.h

@@ -41,6 +41,8 @@ typedef int (patty_ax25_if_driver_fd)(void *);
 
 typedef int (patty_ax25_if_driver_ready)(void *, fd_set *);
 
+typedef int (patty_ax25_if_driver_reset)(void *);
+
 typedef ssize_t (patty_ax25_if_driver_fill)(void *);
 
 typedef ssize_t (patty_ax25_if_driver_drain)(void *, void *, size_t);
@@ -57,6 +59,7 @@ typedef struct _patty_ax25_if_driver {
     patty_ax25_if_driver_stats *stats;
     patty_ax25_if_driver_fd *fd;
     patty_ax25_if_driver_ready *ready;
+    patty_ax25_if_driver_reset *reset;
     patty_ax25_if_driver_fill *fill;
     patty_ax25_if_driver_drain *drain;
     patty_ax25_if_driver_pending *pending;
@@ -123,6 +126,8 @@ int patty_ax25_if_fd(patty_ax25_if *iface);
 
 int patty_ax25_if_ready(patty_ax25_if *iface, fd_set *fds);
 
+int patty_ax25_if_reset(patty_ax25_if *iface);
+
 ssize_t patty_ax25_if_fill(patty_ax25_if *iface);
 
 ssize_t patty_ax25_if_drain(patty_ax25_if *iface, void *buf, size_t len);

include/patty/kiss/tnc.h

@@ -37,6 +37,8 @@ int patty_kiss_tnc_fd(patty_kiss_tnc *tnc);
 
 int patty_kiss_tnc_ready(patty_kiss_tnc *tnc, fd_set *fds);
 
+int patty_kiss_tnc_reset(patty_kiss_tnc *tnc);
+
 void patty_kiss_tnc_destroy(patty_kiss_tnc *tnc);
 
 ssize_t patty_kiss_tnc_fill(patty_kiss_tnc *tnc);

src/aprs_is.c

@@ -161,7 +161,7 @@ error_malloc_aprs:
 }
 
 void patty_ax25_aprs_is_destroy(patty_ax25_aprs_is *aprs) {
-    (void)close(aprs->fd);
+    close(aprs->fd);
 
     free(aprs);
 }
@@ -178,19 +178,25 @@ int patty_ax25_aprs_is_ready(patty_ax25_aprs_is *aprs, fd_set *fds) {
     return FD_ISSET(aprs->fd, fds);
 }
 
-ssize_t patty_ax25_aprs_is_fill(patty_ax25_aprs_is *aprs) {
-    int attempt = 0;
+int patty_ax25_aprs_is_reset(patty_ax25_aprs_is *aprs) {
+    int attempt;
 
-    while ((aprs->readlen = read(aprs->fd, aprs->rx_buf, aprs->rx_bufsz)) < 0) {
-        if (errno == EIO) {
-            if (++attempt == PATTY_AX25_APRS_IS_ATTEMPTS_MAX) {
-                (void)aprs_is_connect(aprs, &aprs->info);
-            }
-        } else {
-            goto error_read;
+    close(aprs->fd);
+
+    for (attempt=0; attempt<PATTY_AX25_APRS_IS_ATTEMPTS_MAX; attempt++) {
+        if (aprs_is_connect(aprs, &aprs->info) == 0) {
+            return aprs->fd;
         }
     }
 
+    return -1;
+}
+
+ssize_t patty_ax25_aprs_is_fill(patty_ax25_aprs_is *aprs) {
+    if ((aprs->readlen = read(aprs->fd, aprs->rx_buf, aprs->rx_bufsz)) < 0) {
+        goto error_read;
+    }
+
     aprs->offset_i = 0;
 
     return aprs->readlen;
@@ -450,6 +456,7 @@ patty_ax25_if_driver *patty_ax25_aprs_is_driver() {
         .stats   = (patty_ax25_if_driver_stats *)patty_ax25_aprs_is_stats,
         .fd      = (patty_ax25_if_driver_fd *)patty_ax25_aprs_is_fd,
         .ready   = (patty_ax25_if_driver_ready *)patty_ax25_aprs_is_ready,
+        .reset   = (patty_ax25_if_driver_reset *)patty_ax25_aprs_is_reset,
         .fill    = (patty_ax25_if_driver_fill *)patty_ax25_aprs_is_fill,
         .drain   = (patty_ax25_if_driver_drain *)patty_ax25_aprs_is_drain,
         .pending = (patty_ax25_if_driver_pending *)patty_ax25_aprs_is_pending,

src/if.c

@@ -286,6 +286,18 @@ int patty_ax25_if_ready(patty_ax25_if *iface, fd_set *fds) {
            iface->driver->ready(iface->phy, fds): 0;
 }
 
+int patty_ax25_if_reset(patty_ax25_if *iface) {
+    int ret;
+
+    if ((ret = iface->driver->reset(iface->phy)) < 0) {
+        iface->status = PATTY_AX25_IF_ERROR;
+    } else {
+        iface->status = PATTY_AX25_IF_UP;
+    }
+
+    return ret;
+}
+
 ssize_t patty_ax25_if_fill(patty_ax25_if *iface) {
     return iface->driver->fill(iface->phy);
 }

src/server.c

@@ -2044,7 +2044,15 @@ static int handle_iface(patty_ax25_server *server, struct if_entry *entry) {
     }
 
     if ((len = patty_ax25_if_fill(entry->iface)) < 0) {
-        goto error_io;
+        int fd;
+
+        fd_clear(server, entry->fd);
+
+        if ((fd = patty_ax25_if_reset(entry->iface)) < 0) {
+            goto error_io;
+        }
+
+        fd_watch(server, entry->fd = fd);
     } else if (len == 0) {
         close(entry->fd);
 

src/tnc.c

@@ -239,6 +239,12 @@ int patty_kiss_tnc_ready(patty_kiss_tnc *tnc, fd_set *fds) {
     return FD_ISSET(tnc->fd, fds);
 }
 
+int patty_kiss_tnc_reset(patty_kiss_tnc *tnc) {
+    errno = ENOSYS;
+
+    return -1;
+}
+
 static void tnc_drop(patty_kiss_tnc *tnc) {
     tnc->state    = KISS_NONE;
     tnc->command  = PATTY_KISS_RETURN;
@@ -410,6 +416,7 @@ patty_ax25_if_driver *patty_kiss_tnc_driver() {
         .stats   = (patty_ax25_if_driver_stats *)patty_kiss_tnc_stats,
         .fd      = (patty_ax25_if_driver_fd *)patty_kiss_tnc_fd,
         .ready   = (patty_ax25_if_driver_ready *)patty_kiss_tnc_ready,
+        .reset   = (patty_ax25_if_driver_reset *)patty_kiss_tnc_reset,
         .fill    = (patty_ax25_if_driver_fill *)patty_kiss_tnc_fill,
         .drain   = (patty_ax25_if_driver_drain *)patty_kiss_tnc_drain,
         .pending = (patty_ax25_if_driver_pending *)patty_kiss_tnc_pending,