bus: properly validate object path values

[elogind.git] / src / libsystemd-bus / bus-message.c

diff --git a/src/libsystemd-bus/bus-message.c b/src/libsystemd-bus/bus-message.c
index 5f3dbdb75de8a55d2a41076b045b7de9af0b9507..f5b60f27280cca67e7a9ff30b012a9ee954f9a91 100644 (file)
--- a/src/libsystemd-bus/bus-message.c
+++ b/src/libsystemd-bus/bus-message.c
@@ -23,6 +23,7 @@
 
 #include "util.h"
 #include "utf8.h"
+#include "strv.h"
 
 #include "sd-bus.h"
 #include "bus-message.h"
@@ -322,6 +323,8 @@ int sd_bus_message_new_signal(
         if (!t)
                 return -ENOMEM;
 
+        t->header->flags |= SD_BUS_MESSAGE_NO_REPLY_EXPECTED;
+
         r = message_append_field_string(t, SD_BUS_MESSAGE_HEADER_PATH, SD_BUS_TYPE_OBJECT_PATH, path, &t->path);
         if (r < 0)
                 goto fail;
@@ -400,6 +403,8 @@ static int message_new_reply(
 
         if (!call)
                 return -EINVAL;
+        if (!call->sealed)
+                return -EPERM;
         if (call->header->type != SD_BUS_MESSAGE_TYPE_METHOD_CALL)
                 return -EINVAL;
         if (!m)
@@ -409,6 +414,7 @@ static int message_new_reply(
         if (!t)
                 return -ENOMEM;
 
+        t->header->flags |= SD_BUS_MESSAGE_NO_REPLY_EXPECTED;
         t->reply_serial = BUS_MESSAGE_SERIAL(call);
 
         r = message_append_field_uint32(t, SD_BUS_MESSAGE_HEADER_REPLY_SERIAL, t->reply_serial);
@@ -424,6 +430,7 @@ static int message_new_reply(
         t->dont_send = !!(call->header->flags & SD_BUS_MESSAGE_NO_REPLY_EXPECTED);
 
         *m = t;
+        return 0;
 
 fail:
         message_free(t);
@@ -761,11 +768,27 @@ int message_append_basic(sd_bus_message *m, char type, const void *p, const void
 
         case SD_BUS_TYPE_STRING:
         case SD_BUS_TYPE_OBJECT_PATH:
+
+                if (!p) {
+                        if (e)
+                                c->signature[c->index] = 0;
+
+                        return -EINVAL;
+                }
+
                 align = 4;
                 sz = 4 + strlen(p) + 1;
                 break;
 
         case SD_BUS_TYPE_SIGNATURE:
+
+                if (!p) {
+                        if (e)
+                                c->signature[c->index] = 0;
+
+                        return -EINVAL;
+                }
+
                 align = 1;
                 sz = 1 + strlen(p) + 1;
                 break;
@@ -1351,8 +1374,7 @@ static int message_peek_body(sd_bus_message *m, size_t *rindex, size_t align, si
         return buffer_peek(m->body, BUS_MESSAGE_BODY_SIZE(m), rindex, align, nbytes, ret);
 }
 
-static bool validate_string(const char *s, size_t l) {
-        assert(s);
+static bool validate_nul(const char *s, size_t l) {
 
         /* Check for NUL chars in the string */
         if (memchr(s, 0, l))
@@ -1362,6 +1384,14 @@ static bool validate_string(const char *s, size_t l) {
         if (s[l] != 0)
                 return false;
 
+        return true;
+}
+
+static bool validate_string(const char *s, size_t l) {
+
+        if (!validate_nul(s, l))
+                return false;
+
         /* Check if valid UTF8 */
         if (!utf8_is_valid(s))
                 return false;
@@ -1370,12 +1400,8 @@ static bool validate_string(const char *s, size_t l) {
 }
 
 static bool validate_signature(const char *s, size_t l) {
-        /* Check for NUL chars in the signature */
-        if (memchr(s, 0, l))
-                return false;
 
-        /* Check for NUL termination */
-        if (s[l] != 0)
+        if (!validate_nul(s, l))
                 return false;
 
         /* Check if valid signature */
@@ -1385,6 +1411,17 @@ static bool validate_signature(const char *s, size_t l) {
         return true;
 }
 
+static bool validate_object_path(const char *s, size_t l) {
+
+        if (!validate_nul(s, l))
+                return false;
+
+        if (!object_path_is_valid(s))
+                return false;
+
+        return true;
+}
+
 int sd_bus_message_read_basic(sd_bus_message *m, char type, void *p) {
         struct bus_container *c;
         int r;
@@ -1424,8 +1461,13 @@ int sd_bus_message_read_basic(sd_bus_message *m, char type, void *p) {
                 if (r == 0)
                         return -EBADMSG;
 
-                if (!validate_string(q, l))
-                        return -EBADMSG;
+                if (type == SD_BUS_TYPE_OBJECT_PATH) {
+                        if (!validate_object_path(q, l))
+                                return -EBADMSG;
+                } else {
+                        if (!validate_string(q, l))
+                                return -EBADMSG;
+                }
 
                 m->rindex = rindex;
                 *(const char**) p = q;
@@ -1542,7 +1584,7 @@ static int bus_message_enter_array(
         if (r <= 0)
                 return r;
 
-        if (BUS_MESSAGE_BSWAP32(m, *(uint32_t*) q) > 67108864)
+        if (BUS_MESSAGE_BSWAP32(m, *(uint32_t*) q) > BUS_ARRAY_MAX_SIZE)
                 return -EBADMSG;
 
         r = message_peek_body(m, &rindex, alignment, 0, NULL);
@@ -1891,7 +1933,7 @@ eof:
         return 0;
 }
 
-int sd_bus_message_rewind(sd_bus_message *m, bool complete) {
+int sd_bus_message_rewind(sd_bus_message *m, int complete) {
         struct bus_container *c;
 
         if (!m)
@@ -2081,6 +2123,7 @@ static int message_peek_fields(
 
 static int message_peek_field_string(
                 sd_bus_message *m,
+                char type,
                 size_t *ri,
                 const char **ret) {
 
@@ -2100,8 +2143,13 @@ static int message_peek_field_string(
         if (r < 0)
                 return r;
 
-        if (!validate_string(q, l))
-                return -EBADMSG;
+        if (type == SD_BUS_TYPE_OBJECT_PATH) {
+                if (!validate_object_path(q, l))
+                        return -EBADMSG;
+        } else {
+                if (!validate_string(q, l))
+                        return -EBADMSG;
+        }
 
         if (ret)
                 *ret = q;
@@ -2191,7 +2239,7 @@ static int message_skip_fields(
                 if (t == SD_BUS_TYPE_STRING ||
                     t == SD_BUS_TYPE_OBJECT_PATH) {
 
-                        r = message_peek_field_string(m, ri, NULL);
+                        r = message_peek_field_string(m, t, ri, NULL);
                         if (r < 0)
                                 return r;
 
@@ -2208,8 +2256,8 @@ static int message_skip_fields(
                 } else if (bus_type_is_basic(t)) {
                         size_t align, k;
 
-                        align = bus_type_get_alignment(align);
-                        k = bus_type_get_size(align);
+                        align = bus_type_get_alignment(t);
+                        k = bus_type_get_size(t);
 
                         r = message_peek_fields(m, ri, align, k, NULL);
                         if (r < 0)
@@ -2241,7 +2289,7 @@ static int message_skip_fields(
                                         return r;
 
                                 nas = BUS_MESSAGE_BSWAP32(m, *(uint32_t*) q);
-                                if (nas > 67108864)
+                                if (nas > BUS_ARRAY_MAX_SIZE)
                                         return -EBADMSG;
 
                                 r = message_peek_fields(m, ri, alignment, 0, NULL);
@@ -2318,42 +2366,42 @@ static int message_parse_fields(sd_bus_message *m) {
                         if (!streq(signature, "o"))
                                 return -EBADMSG;
 
-                        r = message_peek_field_string(m, &ri, &m->path);
+                        r = message_peek_field_string(m, 'o', &ri, &m->path);
                         break;
 
                 case SD_BUS_MESSAGE_HEADER_INTERFACE:
                         if (!streq(signature, "s"))
                                 return -EBADMSG;
 
-                        r = message_peek_field_string(m, &ri, &m->interface);
+                        r = message_peek_field_string(m, 's', &ri, &m->interface);
                         break;
 
                 case SD_BUS_MESSAGE_HEADER_MEMBER:
                         if (!streq(signature, "s"))
                                 return -EBADMSG;
 
-                        r = message_peek_field_string(m, &ri, &m->member);
+                        r = message_peek_field_string(m, 's', &ri, &m->member);
                         break;
 
                 case SD_BUS_MESSAGE_HEADER_ERROR_NAME:
                         if (!streq(signature, "s"))
                                 return -EBADMSG;
 
-                        r = message_peek_field_string(m, &ri, &m->error.name);
+                        r = message_peek_field_string(m, 's', &ri, &m->error.name);
                         break;
 
                 case SD_BUS_MESSAGE_HEADER_DESTINATION:
                         if (!streq(signature, "s"))
                                 return -EBADMSG;
 
-                        r = message_peek_field_string(m, &ri, &m->destination);
+                        r = message_peek_field_string(m, 's', &ri, &m->destination);
                         break;
 
                 case SD_BUS_MESSAGE_HEADER_SENDER:
                         if (!streq(signature, "s"))
                                 return -EBADMSG;
 
-                        r = message_peek_field_string(m, &ri, &m->sender);
+                        r = message_peek_field_string(m, 's', &ri, &m->sender);
                         break;
 
 
@@ -2424,6 +2472,10 @@ static int message_parse_fields(sd_bus_message *m) {
                 break;
         }
 
+        /* Try to read the error message, but if we can't it's a non-issue */
+        if (m->header->type == SD_BUS_MESSAGE_TYPE_METHOD_ERROR)
+                sd_bus_message_read(m, "s", &m->error.message);
+
         return 0;
 }
 
@@ -2432,14 +2484,17 @@ static void setup_iovec(sd_bus_message *m) {
         assert(m->sealed);
 
         m->n_iovec = 0;
+        m->size = 0;
 
         m->iovec[m->n_iovec].iov_base = m->header;
         m->iovec[m->n_iovec].iov_len = sizeof(*m->header);
+        m->size += m->iovec[m->n_iovec].iov_len;
         m->n_iovec++;
 
         if (m->fields) {
                 m->iovec[m->n_iovec].iov_base = m->fields;
                 m->iovec[m->n_iovec].iov_len = m->header->fields_size;
+                m->size += m->iovec[m->n_iovec].iov_len;
                 m->n_iovec++;
 
                 if (m->header->fields_size % 8 != 0) {
@@ -2447,6 +2502,7 @@ static void setup_iovec(sd_bus_message *m) {
 
                         m->iovec[m->n_iovec].iov_base = (void*) padding;
                         m->iovec[m->n_iovec].iov_len = 8 - m->header->fields_size % 8;
+                        m->size += m->iovec[m->n_iovec].iov_len;
                         m->n_iovec++;
                 }
         }
@@ -2454,6 +2510,7 @@ static void setup_iovec(sd_bus_message *m) {
         if (m->body) {
                 m->iovec[m->n_iovec].iov_base = m->body;
                 m->iovec[m->n_iovec].iov_len = m->header->body_size;
+                m->size += m->iovec[m->n_iovec].iov_len;
                 m->n_iovec++;
         }
 }
@@ -2724,3 +2781,34 @@ int bus_message_get_blob(sd_bus_message *m, void **buffer, size_t *sz) {
 
         return 0;
 }
+
+int bus_message_read_strv_extend(sd_bus_message *m, char ***l) {
+        int r;
+
+        assert(m);
+        assert(l);
+
+        r = sd_bus_message_enter_container(m, 'a', "s");
+        if (r < 0)
+                return r;
+
+        for (;;) {
+                const char *s;
+
+                r = sd_bus_message_read_basic(m, 's', &s);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                r = strv_extend(l, s);
+                if (r < 0)
+                        return r;
+        }
+
+        r = sd_bus_message_exit_container(m);
+        if (r < 0)
+                return r;
+
+        return 0;
+}