Checkpoint commit: refactoring the request code in TIDS for better reuse

[trust_router.git] / mon / mons.c

diff --git a/mon/mons.c b/mon/mons.c
new file mode 100644 (file)
index 0000000..29f405b
--- /dev/null
+++ b/mon/mons.c
@@ -0,0 +1,163 @@
+/*
+ * Copyright (c) 2018, JANET(UK)
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of JANET(UK) nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <talloc.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <netdb.h>
+
+#include <tr.h>
+#include <tr_debug.h>
+#include <mon_internal.h>
+#include <tr_socket.h>
+#include <sys/wait.h>
+
+/**
+ * Allocate a new MONS_INSTANCE
+ *
+ * @param mem_ctx talloc context for allocation
+ * @return new MONS_INSTANCE or null on failure
+ */
+MONS_INSTANCE *mons_new(TALLOC_CTX *mem_ctx)
+{
+  MONS_INSTANCE *mons = talloc(mem_ctx, MONS_INSTANCE);
+
+  if (mons) {
+    mons->port = 0;
+    mons->req_handler = NULL;
+    mons->auth_handler = NULL;
+    mons->cookie = NULL;
+    mons->authorized_gss_names = tr_gss_names_new(mons);
+    if (mons->authorized_gss_names == NULL) {
+      talloc_free(mons);
+      mons = NULL;
+    }
+  }
+  return mons;
+}
+
+/**
+ * Create a listener for monitoring requests
+ *
+ * Accept connections with mons_accept()
+ *
+ * @param mons monitoring server instance
+ * @param req_handler
+ * @param auth_handler
+ * @param hostname
+ * @param port
+ * @param cookie
+ * @param fd_out
+ * @param max_fd
+ * @return
+ */
+int mons_get_listener(MONS_INSTANCE *mons,
+                      MONS_REQ_FUNC *req_handler,
+                      MONS_AUTH_FUNC *auth_handler,
+                      unsigned int port,
+                      void *cookie,
+                      int *fd_out,
+                      size_t max_fd)
+{
+  size_t n_fd=0;
+  size_t ii=0;
+
+  mons->port = port;
+  n_fd = tr_sock_listen_all(port, fd_out, max_fd);
+  if (n_fd<=0)
+    tr_err("mons_get_listener: Error opening port %d");
+  else {
+    /* opening port succeeded */
+    tr_info("mons_get_listener: Opened port %d.", port);
+
+    /* make this socket non-blocking */
+    for (ii=0; ii<n_fd; ii++) {
+      if (0 != fcntl(fd_out[ii], F_SETFL, O_NONBLOCK)) {
+        tr_err("mons_get_listener: Error setting O_NONBLOCK.");
+        for (ii=0; ii<n_fd; ii++) {
+          close(fd_out[ii]);
+          fd_out[ii]=-1;
+        }
+        n_fd=0;
+        break;
+      }
+    }
+  }
+
+  if (n_fd>0) {
+    /* store the caller's request handler & cookie */
+    mons->req_handler = req_handler;
+    mons->auth_handler = auth_handler;
+    mons->cookie = cookie;
+  }
+
+  return (int) n_fd;
+}
+
+/**
+ * Accept and process a connection on a port opened with mons_get_listener()
+ *
+ * @param mons monitoring interface instance
+ * @param listen FD of the connection socket
+ * @return 0 on success
+ */
+int mons_accept(MONS_INSTANCE *mons, int listen)
+{
+  int conn=-1;
+  int pid=-1;
+
+  if (0 > (conn = accept(listen, NULL, NULL))) {
+    perror("Error from monitoring interface accept()");
+    return 1;
+  }
+
+  if (0 > (pid = fork())) {
+    perror("Error on fork()");
+    return 1;
+  }
+
+  if (pid == 0) {
+    close(listen);
+    mons_handle_connection(mons, conn);
+    close(conn);
+    exit(0); /* exit to kill forked child process */
+  } else {
+    close(conn);
+  }
+
+  /* clean up any processes that have completed */
+  while (waitpid(-1, 0, WNOHANG) > 0);
+
+  return 0;
+}