Added CLIXON_CLIENT_SSH to client API to communicate remotely via SSH netconf sub-system

configure: stringified SSH_BIN
C-API: Added `sock_flags` parameter to `clixon_proc_socket()`

CHANGELOG.md

@@ -41,6 +41,16 @@
 ## 6.1.0
 Expected: beginning of 2023
 
+### C/CLI-API changes on existing features
+Developers may need to change their code
+
+* C-API
+  * Added `sock_flags` parameter to `clixon_proc_socket()`
+  
+### Minor features
+
+* Added `CLIXON_CLIENT_SSH` to client API to communicate remotely via SSH netconf sub-system
+
 ### Corrected Bugs
 
 * Fixed [Netconf monitoring](https://github.com/clicon/clixon/issues/370)

configure

@@ -4607,7 +4607,7 @@ fi
 
 
 cat >>confdefs.h <<_ACEOF
-#define SSH_BIN $SSH_BIN
+#define SSH_BIN "$SSH_BIN"
 _ACEOF
 
 

configure.ac

@@ -149,7 +149,7 @@ fi
 
 # SSH binary path
 AC_PATH_PROG(SSH_BIN, ssh)
-AC_DEFINE_UNQUOTED(SSH_BIN, $SSH_BIN, [SSH binary])
+AC_DEFINE_UNQUOTED(SSH_BIN, "$SSH_BIN", [SSH binary])
 
 # Get "bison" from bison -y or other string
 if test "$YACC" = "${YACC##bison}" ; then

lib/clixon/clixon_client.h

@@ -42,11 +42,25 @@
 typedef void *clixon_handle;
 typedef void *clixon_client_handle;
 
-/* Connection type as parameter to connect */
+/* Connection type as parameter to connect 
+ */
 typedef enum {
-    CLIXON_CLIENT_IPC,      /* Internal IPC API, only experimental use */
+    /* Internal IPC API, connect directly on local UNIX domain socket to backend
-    CLIXON_CLIENT_NETCONF,  /* External Netconf */
+     * or using IP according to CLICON_SOCK_FAMILY setting
-    CLIXON_CLIENT_SSH       /* NYI External Netconf over SSH */
+     * see https://clixon-docs.readthedocs.io/en/latest/netconf.html#ipc 
+     * Must be local on device
+     */
+    CLIXON_CLIENT_IPC,      
+    /* Regular NETCONF via local netconf binary
+     * Fork clixon_netconf locally which in turn communicates with backend
+     * Must be local on device
+     */
+    CLIXON_CLIENT_NETCONF,  
+    /* Regular NETCONF using ssh sub-system via local SSH (openssh) client binary
+     * Fork ssh locally which in turn communicates remotely to device
+     * Must have openssh installed locally and device must have ssh sub-subsystem
+     */
+    CLIXON_CLIENT_SSH  
 } clixon_client_type;
 
 /*
@@ -59,7 +73,9 @@ extern "C" {
     
 clixon_handle clixon_client_init(const char *config_file);
 int   clixon_client_terminate(clixon_handle h);
-clixon_client_handle clixon_client_connect(clixon_handle h, clixon_client_type socktype);
+int   clixon_client_lock(int sock, const int lock, const char *db);
+int   clixon_client_hello(int sock, int version);
+clixon_client_handle clixon_client_connect(clixon_handle h, clixon_client_type socktype, const char *dest);
 int   clixon_client_disconnect(clixon_client_handle ch);
 int   clixon_client_get_bool(clixon_client_handle ch, int *rval, const char *xnamespace, const char *xpath);
 int   clixon_client_get_str(clixon_client_handle ch, char *rval, int n, const char *xnamespace, const char *xpath);

lib/clixon/clixon_netconf_lib.h

@@ -124,7 +124,7 @@ enum error_option{ /* edit-config */
 /* NETCONF framing
  */
 enum framing_type{ 
-    NETCONF_SSH_EOM,     /* RFC 4742, RFC 6242 hello msg (end-of-msg: ]]>]]>)*/
+    NETCONF_SSH_EOM=0,   /* RFC 4742, RFC 6242 hello msg (end-of-msg: ]]>]]>)*/
     NETCONF_SSH_CHUNKED, /* RFC 6242 Chunked framing */
 };
 typedef enum framing_type netconf_framing_type;

lib/clixon/clixon_proc.h

@@ -58,7 +58,7 @@ typedef int (proc_cb_t)(clicon_handle h, process_entry_t *pe, proc_operation *op
 /*
  * Prototypes
  */ 
-int clixon_proc_socket(char **argv, pid_t *pid, int *sock);
+int clixon_proc_socket(char **argv, int sock_flags, pid_t *pid, int *sock);
 int clixon_proc_socket_close(pid_t pid, int sock);
 int clixon_proc_background(char **argv, const char *netns, pid_t *pid);
 int clixon_process_pid(clicon_handle h, const char *name, pid_t *pid);

lib/src/clixon_client.c

@@ -146,7 +146,7 @@ clixon_client_terminate(clicon_handle h)
  * @retval     0      OK
  * @retval     -1     Error
  */
-static int
+int
 clixon_client_lock(int         sock,
                    const int   lock,
                    const char *db)
@@ -204,15 +204,14 @@ clixon_client_lock(int         sock,
 
 /*! Internal function to construct the encoding and hello message
  *
- * @param[in]  sock      Socket
+ * @param[in]  sock     Socket to netconf server
- * @param[in]  namespace Default namespace used for non-prefixed entries in xpath. (Alt use nsc)
+ * @param[in]  version  Netconf version for capability announcement
- * @param[in]  xpath     XPath
- * @param[out] xdata     XML data tree (may or may not include the intended data)
  * @retval     0        OK
  * @retval     -1       Error
  */
-static int
+int
-clixon_client_hello(int sock)
+clixon_client_hello(int sock,
+                    int version)
 {
     int   retval = -1;
     cbuf *msg = NULL;
@@ -222,9 +221,11 @@ clixon_client_hello(int sock)
         clicon_err(OE_PLUGIN, errno, "cbuf_new");
         goto done;
     }
-    cprintf(msg, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
+    //    cprintf(msg, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
     cprintf(msg, "<hello xmlns=\"%s\">", NETCONF_BASE_NAMESPACE);
-    cprintf(msg, "<capabilities><capability>%s</capability></capabilities>", NETCONF_BASE_CAPABILITY_1_1);
+    cprintf(msg, "<capabilities>");
+    cprintf(msg, "<capability>%s</capability>", version==0?NETCONF_BASE_CAPABILITY_1_0:NETCONF_BASE_CAPABILITY_1_1);
+    cprintf(msg, "</capabilities>");
     cprintf(msg, "</hello>");
     cprintf(msg, "]]>]]>");
     if (clicon_msg_send1(sock, msg) < 0)
@@ -237,25 +238,112 @@ clixon_client_hello(int sock)
     return retval;
 }
 
+/*!
+ */
+static int
+clixon_client_connect_netconf(clicon_handle                h,
+                              struct clixon_client_handle *cch)
+{
+    int         retval = -1;
+    int         nr;
+    int         i;
+    char      **argv = NULL;
+    char       *netconf_bin = NULL;
+    struct stat st = {0,};
+    char        dbgstr[8];
+
+    nr = 7;
+    if (clicon_debug_get() != 0)
+        nr += 2;
+    if ((argv = calloc(nr, sizeof(char *))) == NULL){
+        clicon_err(OE_UNIX, errno, "calloc");
+        goto done;
+    }
+    i = 0;
+    if ((netconf_bin = getenv("CLIXON_NETCONF_BIN")) == NULL)
+        netconf_bin = CLIXON_NETCONF_BIN;
+    if (stat(netconf_bin, &st) < 0){
+        clicon_err(OE_NETCONF, errno, "netconf binary %s. Set with CLIXON_NETCONF_BIN=", 
+                   netconf_bin);
+        goto done;
+    }
+    argv[i++] = netconf_bin;
+    argv[i++] = "-q";
+    argv[i++] = "-f";
+    argv[i++] = clicon_option_str(h, "CLICON_CONFIGFILE");
+    argv[i++] = "-l"; /* log to syslog */
+    argv[i++] = "s";
+    if (clicon_debug_get() != 0){
+        argv[i++] = "-D";
+        snprintf(dbgstr, sizeof(dbgstr)-1, "%d", clicon_debug_get());
+        argv[i++] = dbgstr;
+    }
+    argv[i++] = NULL;
+    assert(i==nr);
+    if (clixon_proc_socket(argv, SOCK_DGRAM, &cch->cch_pid, &cch->cch_socket) < 0){
+        goto done;
+    }
+    retval = 0;
+ done:
+    return retval;
+}
+
+/*!
+ */
+static int
+clixon_client_connect_ssh(clicon_handle                h,
+                          struct clixon_client_handle *cch,
+                          const char                  *dest)
+{
+    int         retval = -1;
+    int         nr;
+    int         i;
+    char      **argv = NULL;
+    char       *ssh_bin = SSH_BIN;
+    struct stat st = {0,};
+
+    clicon_debug(1, "%s", __FUNCTION__);
+    nr = 5;
+    if ((argv = calloc(nr, sizeof(char *))) == NULL){
+        clicon_err(OE_UNIX, errno, "calloc");
+        goto done;
+    }
+    i = 0;
+    if (stat(ssh_bin, &st) < 0){
+        clicon_err(OE_NETCONF, errno, "ssh binary %s", ssh_bin);
+        goto done;
+    }
+    argv[i++] = ssh_bin;
+    argv[i++] = (char*)dest;
+    argv[i++] = "-s";
+    argv[i++] = "netconf";
+    argv[i++] = NULL;
+    assert(i==nr);
+    for (i=0;i<nr;i++)
+        clicon_debug(1, "%s: argv[%d]:%s", __FUNCTION__, i, argv[i]);
+    if (clixon_proc_socket(argv, SOCK_STREAM, &cch->cch_pid, &cch->cch_socket) < 0){
+        goto done;
+    }
+    retval = 0;
+ done:
+    return retval;
+}
+
 /*! Connect client to clixon backend according to config and return a socket
  * @param[in]  h        Clixon handle
  * @param[in]  socktype Type of socket, internal/external/netconf/ssh
+ * @param[in]  dest     Destination for some types
  * @retval     ch       Clixon session handler
  * @retval     NULL     Error
  * @see clixon_client_disconnect  Close the socket returned here
  */
 clixon_client_handle
 clixon_client_connect(clicon_handle      h,
-                      clixon_client_type socktype)
+                      clixon_client_type socktype,
+                      const char        *dest)
 {
     struct clixon_client_handle *cch = NULL;
-    char                       **argv = NULL;
-    int                          nr;
-    int                          i;
-    char                        *netconf_bin = NULL;
-    struct stat                  st = {0,};
     size_t                       sz = sizeof(struct clixon_client_handle);
-    char                         dbgstr[8];
     
     clicon_debug(1, "%s", __FUNCTION__);
     if ((cch = malloc(sz)) == NULL){
@@ -271,48 +359,19 @@ clixon_client_connect(clicon_handle      h,
             goto err;
         break;
     case CLIXON_CLIENT_NETCONF:
-        nr = 7;
+        if (clixon_client_connect_netconf(h, cch) < 0)
-        if (clicon_debug_get() != 0)
-            nr += 2;
-        if ((argv = calloc(nr, sizeof(char *))) == NULL){
-            clicon_err(OE_UNIX, errno, "calloc");
-            goto err;
-        }
-        i = 0;
-        if ((netconf_bin = getenv("CLIXON_NETCONF_BIN")) == NULL)
-            netconf_bin = CLIXON_NETCONF_BIN;
-        if (stat(netconf_bin, &st) < 0){
-            clicon_err(OE_NETCONF, errno, "netconf binary %s. Set with CLIXON_NETCONF_BIN=", 
-                       netconf_bin);
-            goto err;
-        }
-        argv[i++] = netconf_bin;
-        argv[i++] = "-q";
-        argv[i++] = "-f";
-        argv[i++] = clicon_option_str(h, "CLICON_CONFIGFILE");
-        argv[i++] = "-l"; /* log to syslog */
-        argv[i++] = "s";
-        if (clicon_debug_get() != 0){
-            argv[i++] = "-D";
-            snprintf(dbgstr, sizeof(dbgstr)-1, "%d", clicon_debug_get());
-            argv[i++] = dbgstr;
-        }
-        argv[i++] = NULL;
-        assert(i==nr);
-        if (clixon_proc_socket(argv, &cch->cch_pid, &cch->cch_socket) < 0){
-            goto err;
-        }
-        /* Start with encoding and hello message */
-        if (clixon_client_hello(cch->cch_socket) < 0)
             goto err;
         break;
+#ifdef SSH_BIN
     case CLIXON_CLIENT_SSH:
+        if (clixon_client_connect_ssh(h, cch, dest) < 0)
+            goto err;
+#else
+        clicon_err(OE_UNIX, 0, "No ssh bin");
+        goto done;
+#endif
         break;
     } /* switch */
-    /* lock */
-    if (clixon_client_lock(cch->cch_socket, 1, "running") < 0)
-        goto err;
-    cch->cch_locked = 1;
  done:
     clicon_debug(1, "%s retval:%p", __FUNCTION__, cch);
     return cch;
@@ -347,13 +406,12 @@ clixon_client_disconnect(clixon_client_handle ch)
     case CLIXON_CLIENT_IPC:
         close(cch->cch_socket);
         break;
+    case CLIXON_CLIENT_SSH:
     case CLIXON_CLIENT_NETCONF:
         if (clixon_proc_socket_close(cch->cch_pid,
                                      cch->cch_socket) < 0)
             goto done;
         break;
-    case CLIXON_CLIENT_SSH:
-        break;
     }
     free(cch);
     retval = 0;
@@ -403,6 +461,7 @@ clixon_xml_bottom(cxobj  *xtop,
  * @param[out] xdata     XML data tree (may or may not include the intended data)
  * @retval     0         OK
  * @retval     -1        Error
+ * @note configurable netconf framing type, now hardwired to 0
  */
 static int
 clixon_client_get_xdata(int         sock,
@@ -445,9 +504,11 @@ clixon_client_get_xdata(int         sock,
         cprintf(msg, "/>");
     }
     cprintf(msg, "</get-config></rpc>");
-    if (netconf_output_encap(NETCONF_SSH_CHUNKED, msg) < 0)
+    if (netconf_output_encap(0, msg) < 0) // XXX configurable session
         goto done;
-    if (clicon_rpc1(sock, msg, msgret, &eof) < 0)
+    if (clicon_msg_send1(sock, msg) < 0)
+        goto done;
+    if (clicon_msg_rcv1(sock, msgret, &eof) < 0)
         goto done;
     if (eof){
         close(sock);

lib/src/clixon_proc.c

@@ -164,14 +164,17 @@ clixon_proc_sigint(int sig)
 
 /*! Fork a child, exec a child and setup socket to child and return to caller
  * @param[in]  argv       NULL-terminated Argument vector
- * @param[in]  doerr   If non-zero, stderr will be directed to the pipe as well. 
+ * @param[in]  sock_flags Socket type/flags, typically SOCK_DGRAM or SOCK_STREAM, see
- * @param[out] s       Socket
+ * @param[out] pid        Process-id of child
+ * @param[out] sock       Socket
  * @retval     O          OK
  * @retval     -1         Error.
  * @see clixon_proc_socket_close  close sockets, kill child and wait for child termination
+ * @see for flags usage see man sockerpair(2)
  */
 int
 clixon_proc_socket(char **argv,
+                   int    sock_flags,
                    pid_t *pid,
                    int   *sock)
 {
@@ -182,12 +185,6 @@ clixon_proc_socket(char **argv,
     sigset_t oset;
     int      sig = 0;
 
-#ifdef __APPLE__
-    int         sock_flags = SOCK_DGRAM;
-#else
-    int         sock_flags = SOCK_DGRAM | SOCK_CLOEXEC;
-#endif
-    
     if (argv == NULL){
         clicon_err(OE_UNIX, EINVAL, "argv is NULL");
         goto done;
@@ -197,18 +194,6 @@ clixon_proc_socket(char **argv,
         goto done;
     }
 
-#ifdef __APPLE__
-    if (fcntl(sp[0], O_CLOEXEC)) {
-        clicon_err(OE_UNIX, errno, "fcntl, sp[0]");
-        goto done;
-    }
-
-    if (fcntl(sp[1], O_CLOEXEC)) {
-        clicon_err(OE_UNIX, errno, "fcntl, sp[1]");
-        goto done;
-    }
-#endif
-
     sigprocmask(0, NULL, &oset);
     set_signal(SIGINT, clixon_proc_sigint, &oldhandler);
     sig++;

lib/src/clixon_proto.c

@@ -433,6 +433,7 @@ clicon_msg_rcv(int                s,
  * @param[out]  eof    Set if eof encountered
  * @see netconf_input_cb()
  * @see clicon_msg_rcv using IPC message struct
+ * @note only NETCONF version 1.0 EOM framing
  */
 int
 clicon_msg_rcv1(int   s,
@@ -502,7 +503,7 @@ clicon_msg_send1(int   s,
     int retval = -1;
 
     if (atomicio((ssize_t (*)(int, void *, size_t))write, 
-                 s, cbuf_get(cb), cbuf_len(cb)+1) < 0){
+                 s, cbuf_get(cb), cbuf_len(cb)) < 0){
         clicon_err(OE_CFG, errno, "atomicio");
         clicon_log(LOG_WARNING, "%s: write: %s", __FUNCTION__, strerror(errno));
         goto done;

test/test_client.sh

@@ -87,6 +87,7 @@ main(int    argc,
     int retval = -1;
     clixon_handle        h = NULL; /* clixon handle */
     clixon_client_handle ch = NULL; /* clixon client handle */
+    int                  s;
 
     clicon_log_init("client", LOG_DEBUG, CLICON_LOG_STDERR);  // debug
     clicon_debug_init($debug, NULL);                          // debug
@@ -95,9 +96,11 @@ main(int    argc,
     if ((h = clixon_client_init("$cfg")) == NULL)
        return -1;
     /* Make a connection over netconf or ssh/netconf */
-    if ((ch = clixon_client_connect(h, CLIXON_CLIENT_NETCONF)) == NULL)
+    if ((ch = clixon_client_connect(h, CLIXON_CLIENT_NETCONF, NULL)) == NULL)
+       return -1;
+    s = clixon_client_socket_get(ch);
+    if (clixon_client_hello(s, 0) < 0)
       return -1;
-
     /* Here are read functions depending on an example YANG 
      * (Need an example YANG and XML input to confd)
      */