Allow (and document) execution of commands from within

our chat script.
You can now even run chat(8) - see ppp.conf.sample.

3 files changed, 209 insertions, 101 deletions

diff --git a/usr.sbin/ppp/chat.c b/usr.sbin/ppp/chat.c
index aa202db904b..4c3085480ee 100644
--- a/usr.sbin/ppp/chat.c
+++ b/usr.sbin/ppp/chat.c
@@ -18,7 +18,7 @@
  *		Columbus, OH  43221
  *		(614)451-1883
  *
- * $Id: chat.c,v 1.4 1997/12/24 09:30:26 brian Exp $
+ * $Id: chat.c,v 1.5 1997/12/27 07:22:16 brian Exp $
  *
  *  TODO:
  *	o Support more UUCP compatible control sequences.
@@ -66,6 +66,7 @@ static int abort_next, timeout_next;
 static int numaborts;
 static char *AbortStrings[50];
 static char inbuff[IBSIZE * 2 + 1];
+static jmp_buf ChatEnv;
 
 #define	MATCH	1
 #define	NOMATCH	0
@@ -275,6 +276,92 @@ connect_log(const char *str, int single_p)
     flush_log();
 }
 
+static void
+ExecStr(char *command, char *out, int olen)
+{
+  pid_t pid;
+  int fids[2];
+  char *vector[MAXARGS], *startout, *endout;
+  int stat, nb;
+
+  LogPrintf(LogCHAT, "Exec: %s\n", command);
+  MakeArgs(command, vector, VECSIZE(vector));
+
+  if (pipe(fids) < 0) {
+    LogPrintf(LogCHAT, "Unable to create pipe in ExecStr: %s\n",
+	      strerror(errno));
+    longjmp(ChatEnv, 2);
+  }
+  if ((pid = fork()) == 0) {
+    TermTimerService();
+    signal(SIGINT, SIG_DFL);
+    signal(SIGQUIT, SIG_DFL);
+    signal(SIGTERM, SIG_DFL);
+    signal(SIGHUP, SIG_DFL);
+    signal(SIGALRM, SIG_DFL);
+    if (modem == 2) {
+      int nmodem;
+      nmodem = dup(modem);
+      close(modem);
+      modem = nmodem;
+    }
+    close(fids[0]);
+    dup2(fids[1], 2);
+    close(fids[1]);
+    dup2(modem, 0);
+    dup2(modem, 1);
+    if ((nb = open("/dev/tty", O_RDWR)) > 3) {
+      dup2(nb, 3);
+      close(nb);
+    }
+    setuid(geteuid());
+    execvp(vector[0], vector);
+    fprintf(stderr, "execvp failed: %s: %s\n", vector[0], strerror(errno));
+    exit(127);
+  } else {
+    char *name = strdup(vector[0]);
+
+    close(fids[1]);
+    endout = out + olen - 1;
+    startout = out;
+    while (out < endout) {
+      nb = read(fids[0], out, 1);
+      if (nb <= 0)
+	break;
+      out++;
+    }
+    *out = '\0';
+    close(fids[0]);
+    close(fids[1]);
+    waitpid(pid, &stat, WNOHANG);
+    if (WIFSIGNALED(stat)) {
+      LogPrintf(LogWARN, "%s: signal %d\n", name, WTERMSIG(stat));
+      free(name);
+      longjmp(ChatEnv, 3);
+    } else if (WIFEXITED(stat)) {
+      switch (WEXITSTATUS(stat)) {
+        case 0:
+          free(name);
+          break;
+        case 127:
+          LogPrintf(LogWARN, "%s: %s\n", name, startout);
+          free(name);
+          longjmp(ChatEnv, 4);
+          break;
+        default:
+          LogPrintf(LogWARN, "%s: exit %d\n", name, WEXITSTATUS(stat));
+          free(name);
+          longjmp(ChatEnv, 5);
+          break;
+      }
+    } else {
+      LogPrintf(LogWARN, "%s: Unexpected exit result\n", name);
+      free(name);
+      longjmp(ChatEnv, 6);
+    }
+  }
+}
+
 static int
 WaitforString(const char *estr)
 {
@@ -284,16 +371,33 @@ WaitforString(const char *estr)
   fd_set rfds;
   int i, nfds, nb;
   char buff[IBSIZE];
-
-
 #ifdef SIGALRM
   int omask;
 
   omask = sigblock(sigmask(SIGALRM));
 #endif
   clear_log();
-  ExpandString(estr, buff, sizeof buff, 0);
-  LogPrintf(LogCHAT, "Wait for (%d): %s --> %s\n", TimeoutSec, estr, buff);
+  if (*estr == '!') {
+    ExpandString(estr + 1, buff, sizeof buff, 0);
+    ExecStr(buff, buff, sizeof buff);
+  } else {
+    ExpandString(estr, buff, sizeof buff, 0);
+  }
+  if (LogIsKept(LogCHAT)) {
+    s = buff + strlen(buff) - 1;
+    while (s >= buff && *s == '\n')
+      s--;
+    if (!strcmp(estr, buff))
+      LogPrintf(LogCHAT, "Wait for (%d): %.*s\n",
+                TimeoutSec, s - buff + 1, buff);
+    else
+      LogPrintf(LogCHAT, "Wait for (%d): %s --> %.*s\n",
+                TimeoutSec, estr, s - buff + 1, buff);
+  }
+
+  if (buff[0] == '\0')
+    return (MATCH);
+
   str = buff;
   inp = inbuff;
 
@@ -413,74 +517,6 @@ WaitforString(const char *estr)
 }
 
 static void
-ExecStr(char *command, char *out)
-{
-  int pid;
-  int fids[2];
-  char *vector[MAXARGS];
-  int stat, nb;
-  char *cp;
-  char tmp[300];
-
-  cp = inbuff + strlen(inbuff) - 1;
-  while (cp > inbuff) {
-    if (*cp < ' ' && *cp != '\t') {
-      cp++;
-      break;
-    }
-    cp--;
-  }
-  if (snprintf(tmp, sizeof tmp, "%s %s", command, cp) >= sizeof tmp) {
-    LogPrintf(LogCHAT, "Too long string to ExecStr: \"%s\"\n", command);
-    return;
-  }
-  MakeArgs(tmp, vector, VECSIZE(vector));
-
-  if (pipe(fids) < 0) {
-    LogPrintf(LogCHAT, "Unable to create pipe in ExecStr: %s\n",
-	      strerror(errno));
-    return;
-  }
-  pid = fork();
-  if (pid == 0) {
-    TermTimerService();
-    signal(SIGINT, SIG_DFL);
-    signal(SIGQUIT, SIG_DFL);
-    signal(SIGTERM, SIG_DFL);
-    signal(SIGHUP, SIG_DFL);
-    signal(SIGALRM, SIG_DFL);
-    close(fids[0]);
-    if (dup2(fids[1], 1) < 0) {
-      LogPrintf(LogCHAT, "dup2(fids[1], 1) in ExecStr: %s\n", strerror(errno));
-      return;
-    }
-    close(fids[1]);
-    nb = open("/dev/tty", O_RDWR);
-    if (dup2(nb, 0) < 0) {
-      LogPrintf(LogCHAT, "dup2(nb, 0) in ExecStr: %s\n", strerror(errno));
-      return;
-    }
-    setuid(geteuid());
-    LogPrintf(LogCHAT, "exec: %s\n", command);
-    pid = execvp(command, (char **)vector);
-    LogPrintf(LogCHAT, "execvp failed for (%d/%d): %s\n", pid, errno, command);
-    exit(127);
-  } else {
-    close(fids[1]);
-    for (;;) {
-      nb = read(fids[0], out, 1);
-      if (nb <= 0)
-	break;
-      out++;
-    }
-    *out = '\0';
-    close(fids[0]);
-    close(fids[1]);
-    waitpid(pid, &stat, WNOHANG);
-  }
-}
-
-static void
 SendString(const char *str)
 {
   char *cp;
@@ -499,14 +535,18 @@ SendString(const char *str)
   } else {
     if (*str == '!') {
       ExpandString(str + 1, buff + 2, sizeof buff - 2, 0);
-      ExecStr(buff + 2, buff + 2);
+      ExecStr(buff + 2, buff + 2, sizeof buff - 2);
     } else {
       ExpandString(str, buff + 2, sizeof buff - 2, 1);
     }
     if (strstr(str, "\\P"))	/* Do not log the password itself. */
-      LogPrintf(LogCHAT, "sending: %s\n", str);
-    else
-      LogPrintf(LogCHAT, "sending: %s\n", buff + 2);
+      LogPrintf(LogCHAT, "Sending: %s", str);
+    else {
+      cp = buff + strlen(buff + 2) + 1;
+      while (cp >= buff + 2 && *cp == '\n')
+        cp--;
+      LogPrintf(LogCHAT, "Sending: %.*s\n", cp - buff - 1, buff + 2);
+    }
     cp = buff;
     if (DEV_IS_SYNC)
       memcpy(buff, "\377\003", 2);	/* Prepend HDLC header */
@@ -531,9 +571,8 @@ ExpectString(char *str)
     ++timeout_next;
     return (MATCH);
   }
-  LogPrintf(LogCHAT, "Expecting %s\n", str);
+  LogPrintf(LogCHAT, "Expecting: %s\n", str);
   while (*str) {
-
     /*
      * Check whether if string contains sub-send-expect.
      */
@@ -571,7 +610,6 @@ ExpectString(char *str)
 	return (MATCH);
       }
     } else {
-
       /*
        * Simple case. Wait for string.
        */
@@ -581,7 +619,6 @@ ExpectString(char *str)
   return (MATCH);
 }
 
-static jmp_buf ChatEnv;
 static void (*oint) (int);
 
 static void
@@ -596,15 +633,17 @@ DoChat(char *script)
 {
   char *vector[MAXARGS];
   char *const *argv;
-  int argc, n, state;
+  int argc, n, state, err;
 
   if (!script || !*script)
     return MATCH;
 
-  /* While we're chatting, we want an INT to fail us */
-  if (setjmp(ChatEnv)) {
+  if ((err = setjmp(ChatEnv))) {
     signal(SIGINT, oint);
-    return (-1);
+    if (err == 1)
+      /* Caught a SIGINT during chat */
+      return (-1);
+    return (NOMATCH);
   }
   oint = signal(SIGINT, StopDial);
 
diff --git a/usr.sbin/ppp/command.c b/usr.sbin/ppp/command.c
index 53a5d0226e9..c18822bf169 100644
--- a/usr.sbin/ppp/command.c
+++ b/usr.sbin/ppp/command.c
@@ -17,7 +17,7 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * $Id: command.c,v 1.13 1997/12/24 09:30:27 brian Exp $
+ * $Id: command.c,v 1.14 1997/12/27 07:22:16 brian Exp $
  *
  */
 #include <sys/param.h>
@@ -216,7 +216,6 @@ ShellCommand(struct cmdargs const *arg, int bg)
 {
   const char *shell;
   pid_t shpid;
-  FILE *oVarTerm;
   int argc;
   char *argv[MAXARGS];
 
@@ -259,6 +258,13 @@ ShellCommand(struct cmdargs const *arg, int bg)
   if ((shpid = fork()) == 0) {
     int dtablesize, i, fd;
 
+    TermTimerService();
+    signal(SIGINT, SIG_DFL);
+    signal(SIGQUIT, SIG_DFL);
+    signal(SIGTERM, SIG_DFL);
+    signal(SIGHUP, SIG_DFL);
+    signal(SIGALRM, SIG_DFL);
+
     if (VarTerm)
       fd = fileno(VarTerm);
     else if ((fd = open("/dev/null", O_RDWR)) == -1) {
@@ -268,15 +274,6 @@ ShellCommand(struct cmdargs const *arg, int bg)
     for (i = 0; i < 3; i++)
       dup2(fd, i);
 
-    if (fd > 2)
-      if (VarTerm) {
-	oVarTerm = VarTerm;
-	VarTerm = 0;
-	if (oVarTerm && oVarTerm != stdout)
-	  fclose(oVarTerm);
-      } else
-	close(fd);
-
     for (dtablesize = getdtablesize(), i = 3; i < dtablesize; i++)
       close(i);
 
@@ -305,15 +302,16 @@ ShellCommand(struct cmdargs const *arg, int bg)
 	  exit(1);
 	}
       } else if (VarTerm)
-        fprintf(VarTerm, "ppp: Pausing until %s finishes\n", arg->argv[0]);
+        printf("ppp: Pausing until %s finishes\n", arg->argv[0]);
       execvp(argv[0], argv);
     } else {
       if (VarTerm)
-        fprintf(VarTerm, "ppp: Pausing until %s finishes\n", shell);
+        printf("ppp: Pausing until %s finishes\n", shell);
       execl(shell, shell, NULL);
     }
 
-    LogPrintf(LogWARN, "exec() of %s failed\n", arg->argc > 0 ? arg->argv[0] : shell);
+    LogPrintf(LogWARN, "exec() of %s failed\n",
+              arg->argc > 0 ? arg->argv[0] : shell);
     exit(255);
   }
   if (shpid == (pid_t) - 1) {
@@ -324,7 +322,7 @@ ShellCommand(struct cmdargs const *arg, int bg)
     waitpid(shpid, &status, 0);
   }
 
-  TtyCommandMode(1);
+  TtyCommandMode(0);
 
   return (0);
 }
diff --git a/usr.sbin/ppp/ppp.8 b/usr.sbin/ppp/ppp.8
index 1f4c473052f..af5f19c2777 100644
--- a/usr.sbin/ppp/ppp.8
+++ b/usr.sbin/ppp/ppp.8
@@ -1,4 +1,4 @@
-.\" $Id: ppp.8,v 1.10 1997/12/21 03:15:55 brian Exp $
+.\" $Id: ppp.8,v 1.11 1997/12/27 07:22:17 brian Exp $
 .Dd 20 September 1995
 .Os OpenBSD
 .Dt PPP 8
@@ -1931,6 +1931,77 @@ This means that in practice you should use two escapes, for example:
 set dial "... ATDT\\\\T CONNECT"
 .Ed
 .Pp
+It is also possible to execute external commands from the chat script.
+To do this, the first character of the expect or send string is an
+exclaimation mark
+.Pq Dq \&! .
+When the command is executed, standard input and standard output are
+directed to the modem device (see the
+.Dq set device
+command), and standard error is read by
+.Nm
+and substituted as the expect or send string.  If
+.Nm
+is running in interactive mode, file descriptor 4 is attached to
+.Pa /dev/tty .
+.Pp
+For example (wrapped for readability);
+.Bd -literal -offset indent
+set login "TIMEOUT 5 \\"\\" \\"\\" login:--login: ppp \e
+word: ppp \\"!sh \\\\\\\\-c \\\\\\"echo \\\\\\\\-n label: >&2\\\\\\"\\" \e
+\\"!/bin/echo in\\" HELLO"
+.Ed
+.Pp
+would result in the following chat sequence (output using the
+.Sq set log local chat
+command before dialing):
+.Bd -literal -offset indent
+Dial attempt 1 of 1
+dial OK!
+Chat: Expecting: 
+Chat: Sending: 
+Chat: Expecting: login:--login:
+Chat: Wait for (5): login:
+Chat: Sending: ppp
+Chat: Expecting: word:
+Chat: Wait for (5): word:
+Chat: Sending: ppp
+Chat: Expecting: !sh \\-c "echo \\-n label: >&2"
+Chat: Exec: sh -c "echo -n label: >&2"
+Chat: Wait for (5): !sh \\-c "echo \\-n label: >&2" --> label:
+Chat: Exec: /bin/echo in
+Chat: Sending: 
+Chat: Expecting: HELLO
+Chat: Wait for (5): HELLO
+login OK!
+.Ed
+.Pp
+Note (again) the use of the escape character, allowing many levels of
+nesting.  Here, there are four parsers at work.  The first parses the
+original line, reading it as three arguments.  The second parses the
+third argument, reading it as 11 arguments.  At this point, it is
+important that the
+.Dq \&-
+signs are escaped, otherwise this parser will see them as constituting
+an expect-send-expect sequence.  When the
+.Dq \&!
+character is seen, the execution parser reads the first command as three
+arguments, and then
+.Xr sh 1
+itself expands the argument after the
+.Fl c .
+As we wish to send the output back to the modem, in the first example
+we redirect our output to file descriptor 2 (stderr) so that
+.Nm
+itself sends and logs it, and in the second example, we just output to stdout,
+which is attached directly to the modem.
+.Pp
+This, of course means that it is possible to execute an entirely external
+.Dq chat
+command rather than using the internal one.  See
+.Xr chat 8
+for a good alternative.
+.Pp
 .It set hangup chat-script
 This specifies the chat script that will be used to reset the modem
 before it is closed.  It should not normally be necessary, but can