[tor-commits] [obfsproxy/master] Fix obfs2 argument parsing.

[asn at torproject.org]

commit ee63d3fa345ed7230d229433416e75d4c43d7436
Author: George Kadianakis <desnacked at riseup.net>
Date:   Wed Apr 11 22:31:30 2012 +0200

    Fix obfs2 argument parsing.
    
    Keep a count of how many command line arguments we have left, so that
    we know when to stop parsing.
---
 ChangeLog             |    5 +++++
 src/protocols/obfs2.c |   11 ++++++++++-
 2 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 2a7605c..ae2ee92 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Changes in version 0.1.4 - <not yet released>
+ - Fix crash when parsing obfs2 command line arguments. Fixes bug
+   #5141.
+
+
 Changes in version 0.1.3 - 2012-04-03
  - Display git revision when we start logging. Fixes part of bug
    #5157.
diff --git a/src/protocols/obfs2.c b/src/protocols/obfs2.c
index 59c3d55..566c2ed 100644
--- a/src/protocols/obfs2.c
+++ b/src/protocols/obfs2.c
@@ -167,6 +167,7 @@ int
 parse_and_set_options(int n_options, const char *const *options,
                       obfs2_config_t *cfg)
 {
+  int options_left = n_options;
   int got_dest=0;
   int got_ss=0;
   const char* defport;
@@ -177,7 +178,7 @@ parse_and_set_options(int n_options, const char *const *options,
   }
 
   /* Now parse the optional arguments */
-  while (!strncmp(*options,"--",2)) {
+  while (options_left && !strncmp(*options,"--",2)) {
     if (!strncmp(*options,"--dest=",7)) {
       if (got_dest)
         return -1;
@@ -201,9 +202,17 @@ parse_and_set_options(int n_options, const char *const *options,
       log_warn("obfs2: Unknown argument '%s'.", *options);
       return -1;
     }
+    options_left--;
     options++;
   }
 
+  /* we still need to parse the mode and the listen address. */
+  if (options_left != 2) {
+    log_warn("obfs2 needs two options (mode, listen address), after its "
+             "optional arguments. You provided %d.", options_left);
+    return -1;
+  }
+
   if (!strcmp(*options, "client")) {
     defport = "48988"; /* bf5c */
     cfg->mode = LSN_SIMPLE_CLIENT;