Adding upstream version 5.2.37.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

examples/loadables/accept.c

@@ -0,0 +1,245 @@
+/* accept - listen for and accept a remote network connection on a given port */
+
+/*
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "bashtypes.h"
+#include <errno.h>
+#include <time.h>
+#include <limits.h>
+#include "typemax.h"
+
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+
+#include "loadables.h"
+
+static int accept_bind_variable (char *, int);
+
+int
+accept_builtin (list)
+     WORD_LIST *list;
+{
+  SHELL_VAR *v;
+  intmax_t iport;
+  int opt;
+  char *tmoutarg, *fdvar, *rhostvar, *rhost, *bindaddr;
+  unsigned short uport;
+  int servsock, clisock;
+  struct sockaddr_in server, client;
+  socklen_t clientlen;
+  struct timeval timeval;
+  struct linger linger = { 0, 0 };
+
+  rhostvar = tmoutarg = fdvar = rhost = bindaddr = (char *)NULL;
+
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "b:r:t:v:")) != -1)
+    {
+      switch (opt)
+	{
+	case 'b':
+	  bindaddr = list_optarg;
+	  break;
+	case 'r':
+	  rhostvar = list_optarg;
+	  break;
+	case 't':
+	  tmoutarg = list_optarg;
+	  break;
+	case 'v':
+	  fdvar = list_optarg;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  
+  list = loptend;
+
+  /* Validate input and variables */
+  if (tmoutarg)
+    {
+      long ival, uval;
+      opt = uconvert (tmoutarg, &ival, &uval, (char **)0);
+      if (opt == 0 || ival < 0 || uval < 0)
+	{
+	  builtin_error ("%s: invalid timeout specification", tmoutarg);
+	  return (EXECUTION_FAILURE);
+	}
+      timeval.tv_sec = ival;
+      timeval.tv_usec = uval;
+      /* XXX - should we warn if ival == uval == 0 ? */
+    }
+
+  if (list == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  if (legal_number (list->word->word, &iport) == 0 || iport < 0 || iport > TYPE_MAXIMUM (unsigned short))
+    {
+      builtin_error ("%s: invalid port number", list->word->word);
+      return (EXECUTION_FAILURE);
+    }
+  uport = (unsigned short)iport;
+
+  if (fdvar == 0)
+    fdvar = "ACCEPT_FD";
+
+  unbind_variable (fdvar);
+  if (rhostvar)
+    unbind_variable (rhostvar);
+    
+  if ((servsock = socket (AF_INET, SOCK_STREAM, IPPROTO_IP)) < 0)
+    {
+      builtin_error ("cannot create socket: %s", strerror (errno));
+      return (EXECUTION_FAILURE);
+    }
+
+  memset ((char *)&server, 0, sizeof (server));
+  server.sin_family = AF_INET;
+  server.sin_port = htons(uport);
+  server.sin_addr.s_addr = bindaddr ? inet_addr (bindaddr) : htonl(INADDR_ANY);
+
+  if (server.sin_addr.s_addr == INADDR_NONE)
+    {
+      builtin_error ("invalid address: %s", strerror (errno));
+      return (EXECUTION_FAILURE);
+    }
+
+  opt = 1;
+  setsockopt (servsock, SOL_SOCKET, SO_REUSEADDR, (void *)&opt, sizeof (opt));
+  setsockopt (servsock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof (linger));
+
+  if (bind (servsock, (struct sockaddr *)&server, sizeof (server)) < 0)
+    {
+      builtin_error ("socket bind failure: %s", strerror (errno));
+      close (servsock);
+      return (EXECUTION_FAILURE);
+    }
+
+  if (listen (servsock, 1) < 0)
+    {
+      builtin_error ("listen failure: %s", strerror (errno));
+      close (servsock);
+      return (EXECUTION_FAILURE);
+    }
+
+  if (tmoutarg)
+    {
+      fd_set iofds;
+
+      FD_ZERO(&iofds);
+      FD_SET(servsock, &iofds);
+
+      opt = select (servsock+1, &iofds, 0, 0, &timeval);
+      if (opt < 0)
+	builtin_error ("select failure: %s", strerror (errno));
+      if (opt <= 0)
+	{
+	  close (servsock);
+	  return (EXECUTION_FAILURE);
+	}
+    }
+
+  clientlen = sizeof (client);
+  if ((clisock = accept (servsock, (struct sockaddr *)&client, &clientlen)) < 0)
+    {
+      builtin_error ("client accept failure: %s", strerror (errno));
+      close (servsock);
+      return (EXECUTION_FAILURE);
+    }
+
+  close (servsock);
+
+  accept_bind_variable (fdvar, clisock);  
+  if (rhostvar)
+    {
+      rhost = inet_ntoa (client.sin_addr);
+      v = builtin_bind_variable (rhostvar, rhost, 0);
+      if (v == 0 || readonly_p (v) || noassign_p (v))
+	builtin_error ("%s: cannot set variable", rhostvar);
+    }
+
+  return (EXECUTION_SUCCESS);
+}
+
+static int
+accept_bind_variable (varname, intval)
+     char *varname;
+     int intval;
+{
+  SHELL_VAR *v;
+  char ibuf[INT_STRLEN_BOUND (int) + 1], *p;
+
+  p = fmtulong (intval, 10, ibuf, sizeof (ibuf), 0);
+  v = builtin_bind_variable (varname, p, 0);		/* XXX */
+  if (v == 0 || readonly_p (v) || noassign_p (v))
+    builtin_error ("%s: cannot set variable", varname);
+  return (v != 0);
+}
+
+char *accept_doc[] = {
+	"Accept a network connection on a specified port.",
+	""
+	"This builtin allows a bash script to act as a TCP/IP server.",
+	"",
+	"Options, if supplied, have the following meanings:",
+	"    -b address    use ADDRESS as the IP address to listen on; the",
+	"                  default is INADDR_ANY",
+	"    -t timeout    wait TIMEOUT seconds for a connection. TIMEOUT may",
+	"                  be a decimal number including a fractional portion",
+	"    -v varname    store the numeric file descriptor of the connected",
+	"                  socket into VARNAME. The default VARNAME is ACCEPT_FD",
+	"    -r rhost      store the IP address of the remote host into the shell",
+	"                  variable RHOST, in dotted-decimal notation",
+	"",
+	"If successful, the shell variable ACCEPT_FD, or the variable named by the",
+	"-v option, will be set to the fd of the connected socket, suitable for",
+	"use as 'read -u$ACCEPT_FD'. RHOST, if supplied, will hold the IP address",
+	"of the remote client. The return status is 0.",
+	"",
+	"On failure, the return status is 1 and ACCEPT_FD (or VARNAME) and RHOST,",
+	"if supplied, will be unset.",
+	"",
+	"The server socket fd will be closed before accept returns.",
+	(char *) NULL
+};
+
+struct builtin accept_struct = {
+	"accept",		/* builtin name */
+	accept_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	accept_doc,		/* array of long documentation strings. */
+	"accept [-b address] [-t timeout] [-v varname] [-r addrvar ] port",		/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};