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authorLennart Poettering <lennart@poettering.net>2013-05-16 02:04:13 +0200
committerLennart Poettering <lennart@poettering.net>2013-05-16 02:04:13 +0200
commita392d36195f92eaa2d5b7c1d588ff8e52025a43a (patch)
tree9929c75af232b5ceb423091686457da76c803d81
parent3f92e4b4b61042391bd44de4dceb18177df0dd57 (diff)
bus: put together messages with memfd payload correctly
-rw-r--r--src/libsystemd-bus/bus-kernel.c56
-rw-r--r--src/libsystemd-bus/bus-message.c37
-rw-r--r--src/libsystemd-bus/bus-message.h3
-rw-r--r--src/libsystemd-bus/test-bus-zero-copy.c16
4 files changed, 95 insertions, 17 deletions
diff --git a/src/libsystemd-bus/bus-kernel.c b/src/libsystemd-bus/bus-kernel.c
index 54a5e1691c..a0e892a49f 100644
--- 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);
@@ -210,6 +223,9 @@ 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->n_body_parts) *
ALIGN8(offsetof(struct kdbus_item, vec) + sizeof(struct kdbus_vec));
@@ -250,19 +266,38 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
append_destination(&d, m->destination, dl);
append_payload_vec(&d, m->header, BUS_MESSAGE_BODY_BEGIN(m));
- MESSAGE_FOREACH_PART(part, i, m)
+
+ 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;
+ }
+
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)
@@ -274,6 +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) {
diff --git a/src/libsystemd-bus/bus-message.c b/src/libsystemd-bus/bus-message.c
index 747b44ac94..b5a311530b 100644
--- a/src/libsystemd-bus/bus-message.c
+++ b/src/libsystemd-bus/bus-message.c
@@ -2184,7 +2184,7 @@ int sd_bus_message_append_array_memfd(sd_bus_message *m, char type, sd_memfd *me
return sd_bus_message_close_container(m);
}
-static int body_part_map_for_read(struct bus_body_part *part) {
+int bus_body_part_map(struct bus_body_part *part) {
void *p;
size_t psz;
@@ -2210,9 +2210,36 @@ static int body_part_map_for_read(struct bus_body_part *part) {
part->mapped = psz;
part->data = p;
+ part->munmap_this = true;
+
return 0;
}
+void bus_body_part_unmap(struct bus_body_part *part) {
+
+ assert_se(part);
+
+ if (part->memfd < 0)
+ return;
+
+ if (!part->sealed)
+ return;
+
+ if (!part->data)
+ return;
+
+ if (!part->munmap_this)
+ return;
+
+ assert_se(munmap(part->data, part->mapped) == 0);
+
+ part->data = NULL;
+ part->mapped = 0;
+ part->munmap_this = false;
+
+ return;
+}
+
static int buffer_peek(const void *p, uint32_t sz, size_t *rindex, size_t align, size_t nbytes, void **r) {
size_t k, start, end;
@@ -2271,7 +2298,7 @@ static struct bus_body_part* find_part(sd_bus_message *m, size_t index, size_t s
if (index + sz <= begin + part->size) {
- r = body_part_map_for_read(part);
+ r = bus_body_part_map(part);
if (r < 0)
return NULL;
@@ -3709,8 +3736,10 @@ int bus_message_seal(sd_bus_message *m, uint64_t serial) {
MESSAGE_FOREACH_PART(part, i, m)
if (part->memfd >= 0 && !part->sealed) {
- ioctl(part->memfd, KDBUS_CMD_MEMFD_SEAL_SET, 1);
- part->sealed = true;
+ bus_body_part_unmap(part);
+
+ if (ioctl(part->memfd, KDBUS_CMD_MEMFD_SEAL_SET, 1) >= 0)
+ part->sealed = true;
}
m->header->serial = serial;
diff --git a/src/libsystemd-bus/bus-message.h b/src/libsystemd-bus/bus-message.h
index f9c8fc9c08..44390c6b50 100644
--- a/src/libsystemd-bus/bus-message.h
+++ b/src/libsystemd-bus/bus-message.h
@@ -232,3 +232,6 @@ struct bus_body_part *message_append_part(sd_bus_message *m);
#define MESSAGE_FOREACH_PART(part, i, m) \
for ((i) = 0, (part) = &(m)->body; (i) < (m)->n_body_parts; (i)++, (part) = (part)->next)
+
+int bus_body_part_map(struct bus_body_part *part);
+void bus_body_part_unmap(struct bus_body_part *part);
diff --git a/src/libsystemd-bus/test-bus-zero-copy.c b/src/libsystemd-bus/test-bus-zero-copy.c
index 024a0bfddf..0d8435ec1e 100644
--- a/src/libsystemd-bus/test-bus-zero-copy.c
+++ b/src/libsystemd-bus/test-bus-zero-copy.c
@@ -38,6 +38,7 @@ int main(int argc, char *argv[]) {
int r, bus_ref;
sd_bus_message *m;
sd_memfd *f;
+ uint64_t sz;
log_set_max_level(LOG_DEBUG);
@@ -79,21 +80,27 @@ int main(int argc, char *argv[]) {
memset(p, 'L', 32);
- r = sd_memfd_new_and_map(&f, 32, &p);
+ r = sd_memfd_new_and_map(&f, 17, &p);
assert_se(r >= 0);
- memset(p, 'P', 32);
- munmap(p, 32);
+ memset(p, 'P', 17);
+ munmap(p, 17);
- r = sd_memfd_set_size(f, 32);
+ r = sd_memfd_get_size(f, &sz);
assert_se(r >= 0);
+ assert_se(sz == 17);
r = sd_bus_message_append_array_memfd(m, 'y', f);
assert_se(r >= 0);
+ sd_memfd_free(f);
+
r = sd_bus_message_close_container(m);
assert_se(r >= 0);
+ r = sd_bus_message_append(m, "u", 4711);
+ assert_se(r >= 0);
+
r = bus_message_seal(m, 55);
assert_se(r >= 0);
@@ -106,7 +113,6 @@ int main(int argc, char *argv[]) {
sd_bus_unref(a);
sd_bus_unref(b);
- sd_memfd_free(f);
return 0;
}