Protecting and verifying frames

c1332928 · Apr 1, 2011 · b3bfd42 · b3bfd42
1 parent a98f2de
commit b3bfd42
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Showing 4 changed files with 44 additions and 18 deletions.
diff --git a/ampe.c b/ampe.c
@@ -67,7 +67,19 @@
 #include "sae.h"
 
 int
-process_plink_frame (struct ieee80211_mgmt_frame *frame, int *len, int max_len)
+protect_plink_frame (struct ieee80211_mgmt_frame *frame, int *len, int max_len)
 {
+    /* Henceforth this frame is self-protected */
+    frame->action.category = 15;
+    //frame->action.u.var8[0] = 0xbb;
+    return 0;
+}
+
+int
+verify_plink_frame (struct ieee80211_mgmt_frame *frame, int *len, int max_len)
+{
+    /* Henceforth this frame is un-protected */
+    frame->action.category = 13;
+    //frame->action.u.var8[0] = 0xaa;
     return 0;
 }
diff --git a/ampe.h b/ampe.h
@@ -1,7 +1,7 @@
 #ifndef __AMPE_H
 #define __AMPE_H
 /**
- * process_plink_frame - protect peer link management frames
+ * protect_plink_frame - protect peer link management frames
  * gets unsecured mesh peering management frames and returns self protected
  * frames with the right AMPE fields.  All processing is done in place, so
  * the returned frame is ready to be sent.
@@ -15,5 +15,14 @@
  * frame.  If not, the function will return -ENOMEM.
  * Returns: 0 on success, negative on failure.
  */
-int process_plink_frame (struct ieee80211_mgmt_frame *frame, int *len, int max_len);
+int protect_plink_frame (struct ieee80211_mgmt_frame *frame, int *len, int max_len);
+
+/**
+ * verify_plink_frame - verify peer link management frames
+ *
+ * See above funtion for arguments.
+ *
+ * Returns: 0 on success, negative on failure.
+ */
+int verify_plink_frame (struct ieee80211_mgmt_frame *frame, int *len, int max_len);
 #endif
diff --git a/ieee802_11.h b/ieee802_11.h
@@ -116,6 +116,14 @@ struct ieee80211_mgmt_frame {
                 unsigned short var16[0];
             }u;
         } __attribute__ ((packed)) beacon;
+        struct {
+            unsigned char category;
+            unsigned char action;
+            union {
+                unsigned char var8[0];
+                unsigned short var16[0];
+            }u;
+        } __attribute__ ((packed)) action;
     };
 } __attribute__ ((packed));
 

diff --git a/linux/meshd-nl80211.c b/linux/meshd-nl80211.c
@@ -344,12 +344,9 @@ static int register_for_plink_frames(struct netlink_config_s *nlcfg)
 #define IEEE80211_FTYPE_MGMT            0x0000
 #define IEEE80211_STYPE_ACTION          0x00D0
         uint16_t frame_type = IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_ACTION;
-        int ret;
+        int ret = 0;
         char *pret;
-#ifdef SOON
-        char action_codes[3][2] = { {15, 1 }, {15, 2}, {15, 3}};  /* 11s draft 10.0, Table 7-24, Self-Protected */
-#endif
-        char action_codes[3][2] = { {30, 0 }, {30, 1}, {30, 2}};  /* This is what the kernel now gives us */
+        char action_codes[3][2] = {{15, 1 }, {15, 2}, {15, 3}};  /* 11s draft 10.0, Table 7-24, Self-Protected */
 
         for (i = 0; i < 3; i++) {
             msg = nlmsg_alloc();
@@ -492,16 +489,16 @@ static int event_handler(struct nl_msg *msg, void *arg)
                 /* Action (peer link) frames go to AMPE */
                 } else if (frame->frame_control == htole16((IEEE802_11_FC_TYPE_MGMT << 2 |
                                                       IEEE802_11_FC_STYPE_ACTION << 4))) {
-                    if (process_plink_frame(frame, &frame_len, frame_len))
-                        fprintf(stderr, "libsae: process_plink_frame failed\n");
-                    else {
-                         /* The current 11s draft requires that address 3
-                          * (BSSID) == address2, but frames that we get from
-                          * the kernel may conform to older 11s drafts and use
-                          * a null BSSID. */
-                        memcpy(frame->bssid, frame->sa, ETH_ALEN);
-                        meshd_write_mgmt((char*) frame, frame_len);
-                    }
+                    /* ingress (to be verified)? */
+                    if (memcmp(frame->da, nlcfg.mymacaddr, ETH_ALEN) == 0) {
+                        fprintf(stderr, "verifying frame\n");
+                        verify_plink_frame(frame, &frame_len, frame_len);
+                    } else if (memcmp(frame->sa, nlcfg.mymacaddr, ETH_ALEN) == 0) {
+                        fprintf(stderr, "protecting frame\n");
+                        protect_plink_frame(frame, &frame_len, frame_len);
+                    } else
+                        debug_msg("got unexpected frame (%d.%d)\n", now.tv_sec, now.tv_usec);
+                    meshd_write_mgmt((char*) frame, frame_len);
                 } else
                     debug_msg("got unexpected frame (%d.%d)\n", now.tv_sec, now.tv_usec);
             }