Check argument for nasty chars. Add diagnostics when something goes wrong

1 files changed, 37 insertions, 18 deletions

diff --git a/ssh-bleach.c b/ssh-bleach.c
index 00ea33f..41c7bda 100644
--- a/ssh-bleach.c
+++ b/ssh-bleach.c
@@ -21,36 +21,53 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <stdarg.h>
+#include <errno.h>
 
 int verbose = 0;
 
+void panic (char *fmt, ...)
+{
+    va_list ap;
+
+    va_start (ap, fmt);
+    vfprintf (stderr, fmt, ap);
+    va_end (ap);
+    exit (1);
+}
+    
 int cvs_server (char *line) {
     if (verbose)
 	printf ("cvs server\n");
-    return execl ("/usr/bin/cvs", "cvs", "server", NULL);
+    (void) execl ("/usr/bin/cvs", "cvs", "server", NULL);
+    panic ("exec /usr/bin/cvs failed: \"%s\"\n", strerror (errno));
 }
 
+const char bad_chars[] = "\"$%'*;<>?[\\]`|";
+
 char *get_quoted_arg (char *line)
 {
     char    *first = strchr (line, '\'');
     char    *old;
     char    *last;
     char    *new, *n;
+    char    c;
     
     if (!first)
-	return NULL;
+	panic ("Expected quoted argument\n");
     last = strrchr (line, '\'');
     if (!last || last == first)
-	return NULL;
+	panic ("Missing close quote\n");
     first++;
     new = malloc (last - first + 1);
     if (!new)
-	return NULL;
+	panic ("Out of memory\n");
     n = new;
     for (old = first; old < last; old++) {
-	if (*old == '\\')
-	    continue;
-	*n++ = *old;
+	c = *old;
+	if (strchr (bad_chars, c))
+	    panic ("Invalid character in argument \"%c\"\n", c);
+	*n++ = c;
     }
     *n++ = '\0';
     if (verbose)
@@ -61,27 +78,29 @@ char *get_quoted_arg (char *line)
 int git_receive_pack (char *line) {
     char *arg = get_quoted_arg (line);
     if (! arg)
-	return -1;
+	panic ("Missing argument to git-receive-pack\n");
 
     if (verbose)
 	printf ("git-receive-pack '%s'\n", arg);
-    return execl ("/usr/local/bin/git-receive-pack", 
-		  "git-receive-pack",
-		  arg,
-		  NULL);
+    execl ("/usr/local/bin/git-receive-pack", 
+	   "git-receive-pack",
+	   arg,
+	   NULL);
+    panic ("exec /usr/local/bin/git-receive-pack failed: \"%s\"\n", strerror (errno));
 }
 
 int git_upload_pack (char *line) {
     char *arg = get_quoted_arg (line);
     if (! arg)
-	return -1;
+	panic ("Missing argument to git-upload-pack\n");
 
     if (verbose)
 	printf ("git-upload-pack '%s'\n", arg);
-    return execl ("/usr/local/bin/git-upload-pack", 
+    (void) execl ("/usr/local/bin/git-upload-pack", 
 		  "git-upload-pack",
 		  arg,
 		  NULL);
+    panic ("exec /usr/local/bin/git-receive-pack failed: \"%s\"\n", strerror (errno));
 }
 
 struct {
@@ -89,8 +108,8 @@ struct {
     int (*command) (char *line);
 } commands[] = {
     { "cvs server", cvs_server },
-    { "git-receive-pack ", git_receive_pack },
-    { "git-upload-pack ", git_upload_pack },
+    { "git-receive-pack", git_receive_pack },
+    { "git-upload-pack", git_upload_pack },
     { 0 }
 };
 
@@ -102,10 +121,10 @@ int main (int argc, char **argv)
     if (argv[1] && !strcmp (argv[1], "-v"))
 	verbose = 1;
     if (!line)
-	return 1;
+	panic ("Missing original command\n");
     for (i = 0; commands[i].name; i++)
 	if (! strncmp (line, commands[i].name, strlen (commands[i].name)))
 	    if ((*commands[i].command) (line) != 0)
 		break;
-    return 1;
+    panic ("Unsupported command \"%s\"\n", line);
 }