bus: put together messages with memfd payload correctly

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

diff --git a/src/libsystemd-bus/bus-kernel.c b/src/libsystemd-bus/bus-kernel.c
index 3aa408414ee3f79029d5e090e4f17bb4d2021b91..a0e892a49f769ad8ebd3bd8a4f9fb0fb4464b8d1 100644 (file)
--- a/src/libsystemd-bus/bus-kernel.c
+++ b/src/libsystemd-bus/bus-kernel.c
@@ -65,19 +65,32 @@ static int parse_unique_name(const char *s, uint64_t *id) {
 
 static void append_payload_vec(struct kdbus_item **d, const void *p, size_t sz) {
         assert(d);
-        assert(p);
         assert(sz > 0);
 
         *d = ALIGN8_PTR(*d);
 
         (*d)->size = offsetof(struct kdbus_item, vec) + sizeof(struct kdbus_vec);
         (*d)->type = KDBUS_MSG_PAYLOAD_VEC;
-        (*d)->vec.address = (uint64_t) p;
+        (*d)->vec.address = PTR_TO_UINT64(p);
         (*d)->vec.size = sz;
 
         *d = (struct kdbus_item *) ((uint8_t*) *d + (*d)->size);
 }
 
+static void append_payload_memfd(struct kdbus_item **d, int memfd, size_t sz) {
+        assert(d);
+        assert(memfd >= 0);
+        assert(sz > 0);
+
+        *d = ALIGN8_PTR(*d);
+        (*d)->size = offsetof(struct kdbus_item, memfd) + sizeof(struct kdbus_memfd);
+        (*d)->type = KDBUS_MSG_PAYLOAD_MEMFD;
+        (*d)->memfd.fd = memfd;
+        (*d)->memfd.size = sz;
+
+        *d = (struct kdbus_item *) ((uint8_t*) *d + (*d)->size);
+}
+
 static void append_destination(struct kdbus_item **d, const char *s, size_t length) {
         assert(d);
         assert(s);
@@ -210,8 +223,11 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
 
         sz = offsetof(struct kdbus_msg, items);
 
+        assert_cc(ALIGN8(offsetof(struct kdbus_item, vec) + sizeof(struct kdbus_vec)) ==
+                  ALIGN8(offsetof(struct kdbus_item, memfd) + sizeof(struct kdbus_memfd)));
+
         /* Add in fixed header, fields header and payload */
-        sz += (1 + !!m->fields + m->n_body_parts) *
+        sz += (1 + m->n_body_parts) *
                 ALIGN8(offsetof(struct kdbus_item, vec) + sizeof(struct kdbus_vec));
 
         /* Add space for bloom filter */
@@ -249,24 +265,39 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         if (well_known)
                 append_destination(&d, m->destination, dl);
 
-        append_payload_vec(&d, m->header, sizeof(*m->header));
+        append_payload_vec(&d, m->header, BUS_MESSAGE_BODY_BEGIN(m));
 
-        if (m->fields)
-                append_payload_vec(&d, m->fields, ALIGN8(m->header->fields_size));
+        MESSAGE_FOREACH_PART(part, i, m) {
+                if (part->is_zero) {
+                        append_payload_vec(&d, NULL, part->size);
+                        continue;
+                }
+
+                if (part->memfd >= 0 && part->sealed) {
+                        bus_body_part_unmap(part);
+
+                        if (!part->data) {
+                                append_payload_memfd(&d, part->memfd, part->size);
+                                continue;
+                        }
+                }
+
+                if (part->memfd >= 0) {
+                        r = bus_body_part_map(part);
+                        if (r < 0)
+                                goto fail;
+                }
 
-        MESSAGE_FOREACH_PART(part, i, m)
                 append_payload_vec(&d, part->data, part->size);
+        }
 
         if (m->kdbus->dst_id == KDBUS_DST_ID_BROADCAST) {
                 void *p;
 
                 p = append_bloom(&d, BLOOM_SIZE);
                 r = bus_message_setup_bloom(m, p);
-                if (r < 0) {
-                        free(m->kdbus);
-                        m->kdbus = NULL;
-                        return -r;
-                }
+                if (r < 0)
+                        goto fail;
         }
 
         if (m->n_fds > 0)
@@ -278,6 +309,11 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         m->free_kdbus = true;
 
         return 0;
+
+fail:
+        free(m->kdbus);
+        m->kdbus = NULL;
+        return r;
 }
 
 int bus_kernel_take_fd(sd_bus *b) {
@@ -398,22 +434,6 @@ static void close_kdbus_msg(sd_bus *bus, struct kdbus_msg *k) {
         }
 }
 
-static bool range_contains(
-                size_t astart, size_t asize,
-                size_t bstart, size_t bsize,
-                void *a, void **b) {
-
-        if (bstart < astart)
-                return false;
-
-        if (bstart + bsize > astart + asize)
-                return false;
-
-        *b = (uint8_t*) a + (bstart - astart);
-
-        return true;
-}
-
 static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_message **ret) {
         sd_bus_message *m = NULL;
         struct kdbus_item *d;
@@ -439,10 +459,10 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
                 if (d->type == KDBUS_MSG_PAYLOAD_VEC) {
 
                         if (!h) {
-                                if (d->vec.size < sizeof(struct bus_header))
-                                        return -EBADMSG;
-
                                 h = UINT64_TO_PTR(d->vec.address);
+
+                                if (!bus_header_is_complete(h, d->vec.size))
+                                        return -EBADMSG;
                         }
 
                         n_payload++;
@@ -470,7 +490,7 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
         if (!h)
                 return -EBADMSG;
 
-        r = bus_header_size(h, &total);
+        r = bus_header_message_size(h, &total);
         if (r < 0)
                 return r;
 
@@ -489,11 +509,7 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
                 if (d->type == KDBUS_MSG_PAYLOAD_VEC) {
                         size_t begin_body;
 
-                        /* Fill in fields material */
-                        range_contains(idx, d->vec.size, ALIGN8(sizeof(struct bus_header)), BUS_MESSAGE_FIELDS_SIZE(m),
-                                       UINT64_TO_PTR(d->vec.address), &m->fields);
-
-                        begin_body = ALIGN8(sizeof(struct bus_header)) + ALIGN8(BUS_MESSAGE_FIELDS_SIZE(m));
+                        begin_body = BUS_MESSAGE_BODY_BEGIN(m);
 
                         if (idx + d->vec.size > begin_body) {
                                 struct bus_body_part *part;
@@ -507,13 +523,14 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
                                 }
 
                                 if (idx >= begin_body) {
-                                        part->data = (void*) d->vec.address;
+                                        part->data = UINT64_TO_PTR(d->vec.address);
                                         part->size = d->vec.size;
                                 } else {
-                                        part->data = (uint8_t*) (uintptr_t) d->vec.address + (begin_body - idx);
+                                        part->data = d->vec.address != 0 ? (uint8_t*) UINT64_TO_PTR(d->vec.address) + (begin_body - idx) : NULL;
                                         part->size = d->vec.size - (begin_body - idx);
                                 }
 
+                                part->is_zero = d->vec.address == 0;
                                 part->sealed = true;
                         }
 
@@ -551,11 +568,6 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
                         log_debug("Got unknown field from kernel %llu", d->type);
         }
 
-        if ((BUS_MESSAGE_FIELDS_SIZE(m) > 0 && !m->fields)) {
-                sd_bus_message_unref(m);
-                return -EBADMSG;
-        }
-
         r = bus_message_parse_fields(m);
         if (r < 0) {
                 sd_bus_message_unref(m);