chiark / gitweb /
bus: make sure we can match well-known names
[elogind.git] / src / libsystemd-bus / bus-match.c
index ff1edfaaedc620bf470c657a98aac1b4b6eaf343..49fc6335c23d0815b951a5aefd25fb7655e951e1 100644 (file)
@@ -60,7 +60,7 @@
  */
 
 static inline bool BUS_MATCH_IS_COMPARE(enum bus_match_node_type t) {
-        return t >= BUS_MATCH_MESSAGE_TYPE && t <= BUS_MATCH_ARG_NAMESPACE_LAST;
+        return t >= BUS_MATCH_SENDER && t <= BUS_MATCH_ARG_NAMESPACE_LAST;
 }
 
 static inline bool BUS_MATCH_CAN_HASH(enum bus_match_node_type t) {
@@ -142,11 +142,27 @@ static bool value_node_test(
 
         case BUS_MATCH_SENDER:
         case BUS_MATCH_DESTINATION:
+                if (streq_ptr(node->value.str, value_str))
+                        return true;
+
+                /* FIXME: So here's an ugliness: if the match is for a
+                 * well-known name then we cannot actually check this
+                 * correctly here. This doesn't matter much for dbus1
+                 * where no false positives exist, hence we just
+                 * ignore this case here. For kdbus the messages
+                 * should contain all well-known names of the sender,
+                 * hence we can fix things there correctly. */
+
+                if (node->value.str[0] != ':' && value_str[0] == ':')
+                        return true;
+
+                return false;
+
         case BUS_MATCH_INTERFACE:
         case BUS_MATCH_MEMBER:
         case BUS_MATCH_PATH:
         case BUS_MATCH_ARG ... BUS_MATCH_ARG_LAST:
-                return streq(node->value.str, value_str);
+                return streq_ptr(node->value.str, value_str);
 
         case BUS_MATCH_ARG_NAMESPACE ... BUS_MATCH_ARG_NAMESPACE_LAST:
                 return namespace_simple_pattern(node->value.str, value_str);
@@ -199,7 +215,6 @@ static bool value_node_same(
 int bus_match_run(
                 sd_bus *bus,
                 struct bus_match_node *node,
-                int ret,
                 sd_bus_message *m) {
 
 
@@ -212,6 +227,9 @@ int bus_match_run(
         if (!node)
                 return 0;
 
+        if (bus && bus->match_callbacks_modified)
+                return 0;
+
         /* Not these special semantics: when traversing the tree we
          * usually let bus_match_run() when called for a node
          * recursively invoke bus_match_run(). There's are two
@@ -227,7 +245,7 @@ int bus_match_run(
                  * we won't call any. The children of the root node
                  * are compares or leaves, they will automatically
                  * call their siblings. */
-                return bus_match_run(bus, node->child, ret, m);
+                return bus_match_run(bus, node->child, m);
 
         case BUS_MATCH_VALUE:
 
@@ -237,17 +255,29 @@ int bus_match_run(
                  * automatically call their siblings */
 
                 assert(node->child);
-                return bus_match_run(bus, node->child, ret, m);
+                return bus_match_run(bus, node->child, m);
 
         case BUS_MATCH_LEAF:
 
-                /* Run the callback. And then invoke siblings. */
-                assert(node->leaf.callback);
-                r = node->leaf.callback(bus, ret, m, node->leaf.userdata);
-                if (r != 0)
+                if (bus) {
+                        if (node->leaf.last_iteration == bus->iteration_counter)
+                                return 0;
+
+                        node->leaf.last_iteration = bus->iteration_counter;
+                }
+
+                r = sd_bus_message_rewind(m, true);
+                if (r < 0)
                         return r;
 
-                return bus_match_run(bus, node->next, ret, m);
+                /* Run the callback. And then invoke siblings. */
+                if (node->leaf.callback) {
+                        r = node->leaf.callback(bus, m, node->leaf.userdata);
+                        if (r != 0)
+                                return r;
+                }
+
+                return bus_match_run(bus, node->next, m);
 
         case BUS_MATCH_MESSAGE_TYPE:
                 test_u8 = m->header->type;
@@ -304,7 +334,7 @@ int bus_match_run(
                         found = NULL;
 
                 if (found) {
-                        r = bus_match_run(bus, found, ret, m);
+                        r = bus_match_run(bus, found, m);
                         if (r != 0)
                                 return r;
                 }
@@ -317,14 +347,17 @@ int bus_match_run(
                         if (!value_node_test(c, node->type, test_u8, test_str))
                                 continue;
 
-                        r = bus_match_run(bus, c, ret, m);
+                        r = bus_match_run(bus, c, m);
                         if (r != 0)
                                 return r;
                 }
         }
 
+        if (bus && bus->match_callbacks_modified)
+                return 0;
+
         /* And now, let's invoke our siblings */
-        return bus_match_run(bus, node->next, ret, m);
+        return bus_match_run(bus, node->next, m);
 }
 
 static int bus_match_add_compare_value(
@@ -481,8 +514,9 @@ static int bus_match_find_compare_value(
 
 static int bus_match_add_leaf(
                 struct bus_match_node *where,
-                sd_message_handler_t callback,
+                sd_bus_message_handler_t callback,
                 void *userdata,
+                uint64_t cookie,
                 struct bus_match_node **ret) {
 
         struct bus_match_node *n;
@@ -502,6 +536,7 @@ static int bus_match_add_leaf(
                 n->next->prev = n;
         n->leaf.callback = callback;
         n->leaf.userdata = userdata;
+        n->leaf.cookie = cookie;
 
         where->child = n;
 
@@ -511,7 +546,7 @@ static int bus_match_add_leaf(
 
 static int bus_match_find_leaf(
                 struct bus_match_node *where,
-                sd_message_handler_t callback,
+                sd_bus_message_handler_t callback,
                 void *userdata,
                 struct bus_match_node **ret) {
 
@@ -536,22 +571,22 @@ static int bus_match_find_leaf(
 enum bus_match_node_type bus_match_node_type_from_string(const char *k, size_t n) {
         assert(k);
 
-        if (n == 4 && memcmp(k, "type", 4) == 0)
+        if (n == 4 && startswith(k, "type"))
                 return BUS_MATCH_MESSAGE_TYPE;
-        if (n == 6 && memcmp(k, "sender", 6) == 0)
+        if (n == 6 && startswith(k, "sender"))
                 return BUS_MATCH_SENDER;
-        if (n == 11 && memcmp(k, "destination", 11) == 0)
+        if (n == 11 && startswith(k, "destination"))
                 return BUS_MATCH_DESTINATION;
-        if (n == 9 && memcmp(k, "interface", 9) == 0)
+        if (n == 9 && startswith(k, "interface"))
                 return BUS_MATCH_INTERFACE;
-        if (n == 6 && memcmp(k, "member", 6) == 0)
+        if (n == 6 && startswith(k, "member"))
                 return BUS_MATCH_MEMBER;
-        if (n == 4 && memcmp(k, "path", 4) == 0)
+        if (n == 4 && startswith(k, "path"))
                 return BUS_MATCH_PATH;
-        if (n == 14 && memcmp(k, "path_namespace", 14) == 0)
+        if (n == 14 && startswith(k, "path_namespace"))
                 return BUS_MATCH_PATH_NAMESPACE;
 
-        if (n == 4 && memcmp(k, "arg", 3) == 0) {
+        if (n == 4 && startswith(k, "arg")) {
                 int j;
 
                 j = undecchar(k[3]);
@@ -561,7 +596,7 @@ enum bus_match_node_type bus_match_node_type_from_string(const char *k, size_t n
                 return BUS_MATCH_ARG + j;
         }
 
-        if (n == 5 && memcmp(k, "arg", 3) == 0) {
+        if (n == 5 && startswith(k, "arg")) {
                 int a, b;
                 enum bus_match_node_type t;
 
@@ -577,7 +612,7 @@ enum bus_match_node_type bus_match_node_type_from_string(const char *k, size_t n
                 return t;
         }
 
-        if (n == 8 && memcmp(k, "arg", 3) == 0 && memcmp(k + 4, "path", 4) == 0) {
+        if (n == 8 && startswith(k, "arg") && startswith(k + 4, "path")) {
                 int j;
 
                 j = undecchar(k[3]);
@@ -587,7 +622,7 @@ enum bus_match_node_type bus_match_node_type_from_string(const char *k, size_t n
                 return BUS_MATCH_ARG_PATH + j;
         }
 
-        if (n == 9 && memcmp(k, "arg", 3) == 0 && memcmp(k + 5, "path", 4) == 0) {
+        if (n == 9 && startswith(k, "arg") && startswith(k + 5, "path")) {
                 enum bus_match_node_type t;
                 int a, b;
 
@@ -603,7 +638,7 @@ enum bus_match_node_type bus_match_node_type_from_string(const char *k, size_t n
                 return t;
         }
 
-        if (n == 13 && memcmp(k, "arg", 3) == 0 && memcmp(k + 4, "namespace", 9) == 0) {
+        if (n == 13 && startswith(k, "arg") && startswith(k + 4, "namespace")) {
                 int j;
 
                 j = undecchar(k[3]);
@@ -613,7 +648,7 @@ enum bus_match_node_type bus_match_node_type_from_string(const char *k, size_t n
                 return BUS_MATCH_ARG_NAMESPACE + j;
         }
 
-        if (n == 14 && memcmp(k, "arg", 3) == 0 && memcmp(k + 5, "namespace", 9) == 0) {
+        if (n == 14 && startswith(k, "arg") && startswith(k + 5, "namespace")) {
                 enum bus_match_node_type t;
                 int a, b;
 
@@ -632,14 +667,8 @@ enum bus_match_node_type bus_match_node_type_from_string(const char *k, size_t n
         return -EINVAL;
 }
 
-struct match_component {
-        enum bus_match_node_type type;
-        uint8_t value_u8;
-        char *value_str;
-};
-
 static int match_component_compare(const void *a, const void *b) {
-        const struct match_component *x = a, *y = b;
+        const struct bus_match_component *x = a, *y = b;
 
         if (x->type < y->type)
                 return -1;
@@ -649,7 +678,7 @@ static int match_component_compare(const void *a, const void *b) {
         return 0;
 }
 
-static void free_components(struct match_component *components, unsigned n_components) {
+void bus_match_parse_free(struct bus_match_component *components, unsigned n_components) {
         unsigned i;
 
         for (i = 0; i < n_components; i++)
@@ -658,13 +687,13 @@ static void free_components(struct match_component *components, unsigned n_compo
         free(components);
 }
 
-static int parse_match(
+int bus_match_parse(
                 const char *match,
-                struct match_component **_components,
+                struct bus_match_component **_components,
                 unsigned *_n_components) {
 
         const char *p = match;
-        struct match_component *components = NULL;
+        struct bus_match_component *components = NULL;
         size_t components_allocated = 0;
         unsigned n_components = 0, i;
         _cleanup_free_ char *value = NULL;
@@ -712,7 +741,7 @@ static int parse_match(
                                 }
                         }
 
-                        if (!greedy_realloc((void**) &value, &value_allocated, j + 2)) {
+                        if (!GREEDY_REALLOC(value, value_allocated, j + 2)) {
                                 r = -ENOMEM;
                                 goto fail;
                         }
@@ -731,8 +760,7 @@ static int parse_match(
                 } else
                         u = 0;
 
-                if (!greedy_realloc((void**) &components, &components_allocated,
-                                    (n_components + 1) * sizeof(struct match_component))) {
+                if (!GREEDY_REALLOC(components, components_allocated, n_components + 1)) {
                         r = -ENOMEM;
                         goto fail;
                 }
@@ -756,7 +784,7 @@ static int parse_match(
         }
 
         /* Order the whole thing, so that we always generate the same tree */
-        qsort(components, n_components, sizeof(struct match_component), match_component_compare);
+        qsort_safe(components, n_components, sizeof(struct bus_match_component), match_component_compare);
 
         /* Check for duplicates */
         for (i = 0; i+1 < n_components; i++)
@@ -771,29 +799,24 @@ static int parse_match(
         return 0;
 
 fail:
-        free_components(components, n_components);
+        bus_match_parse_free(components, n_components);
         return r;
 }
 
 int bus_match_add(
                 struct bus_match_node *root,
-                const char *match,
-                sd_message_handler_t callback,
+                struct bus_match_component *components,
+                unsigned n_components,
+                sd_bus_message_handler_t callback,
                 void *userdata,
+                uint64_t cookie,
                 struct bus_match_node **ret) {
 
-        struct match_component *components = NULL;
-        unsigned n_components = 0, i;
+        unsigned i;
         struct bus_match_node *n;
         int r;
 
         assert(root);
-        assert(match);
-        assert(callback);
-
-        r = parse_match(match, &components, &n_components);
-        if (r < 0)
-                return r;
 
         n = root;
         for (i = 0; i < n_components; i++) {
@@ -801,38 +824,32 @@ int bus_match_add(
                                 n, components[i].type,
                                 components[i].value_u8, components[i].value_str, &n);
                 if (r < 0)
-                        goto finish;
+                        return r;
         }
 
-        r = bus_match_add_leaf(n, callback, userdata, &n);
+        r = bus_match_add_leaf(n, callback, userdata, cookie, &n);
         if (r < 0)
-                goto finish;
+                return r;
 
         if (ret)
                 *ret = n;
 
-finish:
-        free_components(components, n_components);
-        return r;
+        return 0;
 }
 
 int bus_match_remove(
                 struct bus_match_node *root,
-                const char *match,
-                sd_message_handler_t callback,
-                void *userdata) {
+                struct bus_match_component *components,
+                unsigned n_components,
+                sd_bus_message_handler_t callback,
+                void *userdata,
+                uint64_t *cookie) {
 
-        struct match_component *components = NULL;
-        unsigned n_components = 0, i;
+        unsigned i;
         struct bus_match_node *n, **gc;
         int r;
 
         assert(root);
-        assert(match);
-
-        r = parse_match(match, &components, &n_components);
-        if (r < 0)
-                return r;
 
         gc = newa(struct bus_match_node*, n_components);
 
@@ -843,14 +860,17 @@ int bus_match_remove(
                                 components[i].value_u8, components[i].value_str,
                                 &n);
                 if (r <= 0)
-                        goto finish;
+                        return r;
 
                 gc[i] = n;
         }
 
         r = bus_match_find_leaf(n, callback, userdata, &n);
         if (r <= 0)
-                goto finish;
+                return r;
+
+        if (cookie)
+                *cookie = n->leaf.cookie;
 
         /* Free the leaf */
         bus_match_node_free(n);
@@ -866,8 +886,6 @@ int bus_match_remove(
                         break;
         }
 
-finish:
-        free_components(components, n_components);
         return r;
 }