match.c

@@ -178,7 +178,7 @@ fail:
         } \
     } while(0)
 
-int match_check_sender(BusClient *sender_client, MatchRule *rule)
+int match_check_sender(Bus *s, BusClient *sender_client, MatchRule *rule)
 {
     if (rule->sender) {
         if (sender_client->unique_name) {
@@ -196,7 +196,7 @@ int match_check_sender(BusClient *sender_client, MatchRule *rule)
     return -1;
 }
 
-int match_rule_check(BusClient *sender_client, MatchRule *rule, WireMsg *msg, WireCtx *ctx)
+int match_rule_check(Bus *s, BusClient *sender_client, MatchRule *rule, WireMsg *msg, WireCtx *ctx)
 {
     if (rule->type && msg->type != rule->type) {
         return -1;
@@ -208,7 +208,7 @@ int match_rule_check(BusClient *sender_client, MatchRule *rule, WireMsg *msg, Wi
             return -1;
         }
     } else {
-        if (match_check_sender(sender_client, rule) < 0) {
+        if (match_check_sender(s, sender_client, rule) < 0) {
             return -1;
         }
     }

match.h

@@ -8,6 +8,6 @@
 
 void match_rule_free(MatchRule *rule);
 MatchRule *match_rule_from_string(char *d);
-int match_rule_check(BusClient *sender_client, MatchRule *rule, WireMsg *msg, WireCtx *ctx);
+int match_rule_check(Bus *s, BusClient *sender_client, MatchRule *rule, WireMsg *msg, WireCtx *ctx);
 
 #endif // _JITTERBUG__MATCH_H

server.c

@@ -196,7 +196,7 @@ BusName *bus_name_add(Bus *s, char *name, BusClient *client)
     return NULL;
 }
 
-int bus_client_match_add(BusClient *c, char *match)
+int bus_client_match_add(Bus *s, BusClient *c, char *match)
 {
     for (int i = 0; i < BUS_MAX_MATCH; i++) {
         if (!c->matches[i]) {
@@ -325,7 +325,7 @@ int bus_broadcast_message(Bus *s, BusClient *sender_client, WireMsg *msg, WireCt
             match_left--;
 
             uint32_t previous_cursor = ctx->byte_cursor;
-            if (match_rule_check(sender_client, c->matches[j], msg, ctx) >= 0) {
+            if (match_rule_check(s, sender_client, c->matches[j], msg, ctx) >= 0) {
                 TRYST(wire_compose_unicast_reply(reply_ctx, ctx, msg, sender_client->unique_name->name));
                 TRYST(send(c->fd, reply_ctx->data, reply_ctx->byte_cursor, 0));
                 // TODO?
@@ -360,7 +360,7 @@ int bus_broadcast_signal(Bus *s, BusClient *client, WireCtx *ctx, WireMsg *msg)
             }
 
             match_left--;
-            if (match_rule_check(client, c->matches[j], msg, ctx) >= 0) {
+            if (match_rule_check(s, client, c->matches[j], msg, ctx) >= 0) {
                 uint32_t previous_cursor = ctx->byte_cursor;
                 TRYST(send(c->fd, ctx->data, ctx->byte_cursor, 0));
                 ctx->byte_cursor = previous_cursor;
@@ -399,7 +399,6 @@ int bus_unicast_message(Bus *s, WireMsg *msg, WireCtx *ctx, char *target_name, c
 
 
 #define _reply_begin(M_sig) \
-    (void)s; \
     uint32_t *body_length = NULL; \
     uint32_t body_start = 0; \
     if (!(msg->flags & DBUS_FLAG_NO_REPLY_EXPECTED)) { \
@@ -570,7 +569,7 @@ int handle_add_match(Bus *s, BusClient *client, WireMsg *msg, WireCtx *ctx, Wire
 
     VERBOSE("client index %d adding match rule: '%s'\n", client->fd_index, match);
 
-    TRYST(bus_client_match_add(client, match));
+    TRYST(bus_client_match_add(s, client, match));
 
     _reply_begin("") {} _reply_end()
     return 0;
@@ -815,6 +814,16 @@ int bus_turn(Bus *s)
     static const char auth_data[] = "DATA\r\n";
     static const int data_buffer_len = 16384;
 
+    // We can keep a padding of null bytes for the data buffer. In the event that, for
+    // example, a string function is called on a char array without a proper ending null
+    // byte, we will reach the null bytes here at the end instead, thus preventing a
+    // crash and potential corruption. While this is a good "last line of defense"
+    // against such issues, it is much more important for these kinds of bugs to not
+    // exist in the first place. This mitigation will prevent, for example, ASAN from
+    // finding such bugs. It's recommended that you disable this padding outside
+    // of production so that you can find these bugs.
+    static const int data_buffer_padding = 0;
+
     TRYST(poll(s->fds, s->fd_num, -1));
 
     for (int i = 0; i < s->fd_num; i++) {
@@ -855,7 +864,7 @@ int bus_turn(Bus *s)
             }
 
             // We add padding. See above.
-            char data[data_buffer_len];
+            char data[data_buffer_len + data_buffer_padding];
             ssize_t bytes = recv(fd, data, data_buffer_len, 0);
             if (bytes <= 0) {
                 // error during recv() OR client disconnected, disconnect the client