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bus: add support for adding memfds into message payload

keep-around/ba91431154ad7bac82ddf0a540ec1b40db62d782
Lennart Poettering 10 years ago
parent
commit
453a0c2946
  1. 1
      .gitignore
  2. 13
      Makefile.am
  3. 3
      src/libsystemd-bus/bus-kernel.c
  4. 150
      src/libsystemd-bus/bus-message.c
  5. 7
      src/libsystemd-bus/bus-message.h
  6. 24
      src/libsystemd-bus/sd-memfd.c
  7. 112
      src/libsystemd-bus/test-bus-zero-copy.c
  8. 3
      src/systemd/sd-bus.h
  9. 2
      src/systemd/sd-memfd.h

1
.gitignore

@ -88,6 +88,7 @@
/test-bus-memfd
/test-bus-signature
/test-bus-server
/test-bus-zero-copy
/test-calendarspec
/test-catalog
/test-cgroup

13
Makefile.am

@ -1758,7 +1758,8 @@ tests += \
test-bus-server \
test-bus-match \
test-bus-kernel \
test-bus-memfd
test-bus-memfd \
test-bus-zero-copy
noinst_PROGRAMS += \
busctl
@ -1840,6 +1841,16 @@ test_bus_memfd_LDADD = \
libsystemd-shared.la \
libsystemd-bus.la
test_bus_zero_copy_SOURCES = \
src/libsystemd-bus/test-bus-zero-copy.c
test_bus_zero_copy_CFLAGS = \
$(AM_CFLAGS)
test_bus_zero_copy_LDADD = \
libsystemd-shared.la \
libsystemd-bus.la
busctl_SOURCES = \
src/libsystemd-bus/busctl.c

3
src/libsystemd-bus/bus-kernel.c

@ -486,10 +486,11 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
part->data = UINT64_TO_PTR(d->vec.address);
part->size = d->vec.size;
} else {
part->data = (uint8_t*) UINT64_TO_PTR(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;
}

150
src/libsystemd-bus/bus-message.c

@ -69,7 +69,9 @@ static void message_free_part(sd_bus_message *m, struct bus_body_part *part) {
close_nointr_nofail(part->memfd);
}
} else if (part->free_this)
} else if (part->munmap_this)
munmap(part->data, part->mapped);
else if (part->free_this)
free(part->data);
if (part != &m->body)
@ -1119,8 +1121,13 @@ static void part_zero(struct bus_body_part *part, size_t sz) {
assert(sz > 0);
assert(sz < 8);
part->data = NULL;
/* All other fields can be left in their defaults */
assert(!part->data);
assert(part->memfd < 0);
part->size = sz;
part->is_zero = true;
part->sealed = true;
}
static int part_make_space(
@ -1151,8 +1158,8 @@ static int part_make_space(
return -errno;
}
if (sz > part->mapped) {
size_t psz = PAGE_ALIGN(sz);
if (!part->data || sz > part->mapped) {
size_t psz = PAGE_ALIGN(sz > 0 ? sz : 1);
if (part->mapped <= 0)
n = mmap(NULL, psz, PROT_READ|PROT_WRITE, MAP_SHARED, part->memfd, 0);
@ -1166,6 +1173,7 @@ static int part_make_space(
part->mapped = psz;
part->data = n;
part->munmap_this = true;
}
} else {
n = realloc(part->data, sz);
@ -1185,8 +1193,22 @@ static int part_make_space(
return 0;
}
static void *message_extend_body(sd_bus_message *m, size_t align, size_t sz) {
static void message_extend_containers(sd_bus_message *m, size_t expand) {
struct bus_container *c;
assert(m);
if (expand <= 0)
return;
/* Update counters */
for (c = m->containers; c < m->containers + m->n_containers; c++)
if (c->array_size)
*c->array_size += expand;
}
static void *message_extend_body(sd_bus_message *m, size_t align, size_t sz) {
struct bus_body_part *part = NULL;
size_t start_body, end_body, padding, start_part, end_part, added;
bool add_new_part;
@ -1234,6 +1256,7 @@ static void *message_extend_body(sd_bus_message *m, size_t align, size_t sz) {
if (r < 0)
return NULL;
} else {
struct bus_container *c;
void *op;
size_t os;
@ -1260,12 +1283,8 @@ static void *message_extend_body(sd_bus_message *m, size_t align, size_t sz) {
m->error.message = (const char*) adjust_pointer(m->error.message, op, os, part->data);
}
/* Update counters */
for (c = m->containers; c < m->containers + m->n_containers; c++)
if (c->array_size)
*c->array_size += added;
m->header->body_size = end_body;
message_extend_containers(m, added);
return p;
}
@ -2099,6 +2118,101 @@ int sd_bus_message_append_array(sd_bus_message *m, char type, const void *ptr, s
return 0;
}
int sd_bus_message_append_array_memfd(sd_bus_message *m, char type, sd_memfd *memfd) {
_cleanup_close_ int copy_fd = -1;
struct bus_body_part *part;
ssize_t align, sz;
uint64_t size;
void *a;
int r;
if (!m)
return -EINVAL;
if (!memfd)
return -EINVAL;
if (m->sealed)
return -EPERM;
if (!bus_type_is_trivial(type))
return -EINVAL;
if (m->poisoned)
return -ESTALE;
r = sd_memfd_set_sealed(memfd, true);
if (r < 0)
return r;
copy_fd = sd_memfd_dup_fd(memfd);
if (copy_fd < 0)
return copy_fd;
r = sd_memfd_get_size(memfd, &size);
if (r < 0)
return r;
align = bus_type_get_alignment(type);
sz = bus_type_get_size(type);
assert_se(align > 0);
assert_se(sz > 0);
if (size % sz != 0)
return -EINVAL;
if (size > (size_t) (uint32_t) -1)
return -EINVAL;
r = sd_bus_message_open_container(m, SD_BUS_TYPE_ARRAY, CHAR_TO_STR(type));
if (r < 0)
return r;
a = message_extend_body(m, align, 0);
if (!a)
return -ENOMEM;
part = message_append_part(m);
if (!part)
return -ENOMEM;
part->memfd = copy_fd;
part->sealed = true;
part->size = size;
copy_fd = -1;
message_extend_containers(m, size);
m->header->body_size += size;
return sd_bus_message_close_container(m);
}
static int body_part_map_for_read(struct bus_body_part *part) {
void *p;
size_t psz;
assert_se(part);
if (part->data)
return 0;
if (part->size <= 0)
return 0;
psz = PAGE_ALIGN(part->size);
if (part->memfd >= 0)
p = mmap(NULL, psz, PROT_READ, MAP_SHARED, part->memfd, 0);
else if (part->is_zero)
p = mmap(NULL, psz, PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
else
return -EINVAL;
if (p == MAP_FAILED)
return -errno;
part->mapped = psz;
part->data = p;
return 0;
}
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;
@ -2139,6 +2253,8 @@ static bool message_end_of_array(sd_bus_message *m, size_t index) {
static struct bus_body_part* find_part(sd_bus_message *m, size_t index, size_t sz, void **p) {
struct bus_body_part *part;
size_t begin;
int r;
assert(m);
if (m->cached_rindex_part && index >= m->cached_rindex_part_begin) {
@ -2154,8 +2270,13 @@ static struct bus_body_part* find_part(sd_bus_message *m, size_t index, size_t s
return NULL;
if (index + sz <= begin + part->size) {
r = body_part_map_for_read(part);
if (r < 0)
return NULL;
if (p)
*p = part->data ? (uint8_t*) part->data + index - begin : NULL;
*p = (uint8_t*) part->data + index - begin;
m->cached_rindex_part = part;
m->cached_rindex_part_begin = begin;
@ -2163,6 +2284,7 @@ static struct bus_body_part* find_part(sd_bus_message *m, size_t index, size_t s
return part;
}
begin += part->size;
part = part->next;
}
@ -3638,7 +3760,8 @@ int bus_message_dump(sd_bus_message *m) {
"\treply_serial=%u\n"
"\terror.name=%s\n"
"\terror.message=%s\n"
"\tsealed=%s\n",
"\tsealed=%s\n"
"\tn_body_parts=%u\n",
m,
m->n_ref,
m->header->endian,
@ -3657,7 +3780,8 @@ int bus_message_dump(sd_bus_message *m) {
m->reply_serial,
strna(m->error.name),
strna(m->error.message),
yes_no(m->sealed));
yes_no(m->sealed),
m->n_body_parts);
if (m->pid != 0)
printf("\tpid=%lu\n", (unsigned long) m->pid);

7
src/libsystemd-bus/bus-message.h

@ -33,9 +33,10 @@
struct bus_container {
char enclosing;
char *signature;
unsigned index, saved_index;
char *signature;
uint32_t *array_size;
size_t before, begin;
};
@ -51,13 +52,15 @@ struct bus_header {
} _packed_;
struct bus_body_part {
struct bus_body_part *next;
void *data;
size_t size;
size_t mapped;
int memfd;
bool free_this:1;
bool munmap_this:1;
bool sealed:1;
struct bus_body_part *next;
bool is_zero:1;
};
struct sd_bus_message {

24
src/libsystemd-bus/sd-memfd.c

@ -205,3 +205,27 @@ int sd_memfd_set_size(sd_memfd *m, uint64_t sz) {
return r;
}
int sd_memfd_new_and_map(sd_memfd **m, size_t sz, void **p) {
sd_memfd *n;
int r;
r = sd_memfd_new(&n);
if (r < 0)
return r;
r = sd_memfd_set_size(n, sz);
if (r < 0) {
sd_memfd_free(n);
return r;
}
r = sd_memfd_map(n, 0, sz, p);
if (r < 0) {
sd_memfd_free(n);
return r;
}
*m = n;
return 0;
}

112
src/libsystemd-bus/test-bus-zero-copy.c

@ -0,0 +1,112 @@
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2013 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <fcntl.h>
#include <sys/mman.h>
#include "util.h"
#include "log.h"
#include "sd-bus.h"
#include "sd-memfd.h"
#include "bus-message.h"
#include "bus-error.h"
#include "bus-kernel.h"
int main(int argc, char *argv[]) {
_cleanup_free_ char *bus_name = NULL, *address = NULL;
void *p;
sd_bus *a, *b;
int r, bus_ref;
sd_bus_message *m;
sd_memfd *f;
log_set_max_level(LOG_DEBUG);
bus_ref = bus_kernel_create("deine-mutter", &bus_name);
if (bus_ref == -ENOENT)
return EXIT_TEST_SKIP;
assert_se(bus_ref >= 0);
address = strappend("kernel:path=", bus_name);
assert_se(address);
r = sd_bus_new(&a);
assert_se(r >= 0);
r = sd_bus_new(&b);
assert_se(r >= 0);
r = sd_bus_set_address(a, address);
assert_se(r >= 0);
r = sd_bus_set_address(b, address);
assert_se(r >= 0);
r = sd_bus_start(a);
assert_se(r >= 0);
r = sd_bus_start(b);
assert_se(r >= 0);
r = sd_bus_message_new_method_call(b, ":1.1", "/a/path", "an.inter.face", "AMethod", &m);
assert_se(r >= 0);
r = sd_bus_message_open_container(m, 'r', "ayay");
assert_se(r >= 0);
r = sd_bus_message_append_array_space(m, 'y', 32, &p);
assert_se(r >= 0);
memset(p, 'L', 32);
r = sd_memfd_new_and_map(&f, 32, &p);
assert_se(r >= 0);
memset(p, 'P', 32);
munmap(p, 32);
r = sd_memfd_set_size(f, 32);
assert_se(r >= 0);
r = sd_bus_message_append_array_memfd(m, 'y', f);
assert_se(r >= 0);
r = sd_bus_message_close_container(m);
assert_se(r >= 0);
r = bus_message_seal(m, 55);
assert_se(r >= 0);
bus_message_dump(m);
r = sd_bus_send(b, m, NULL);
assert_se(r >= 0);
sd_bus_message_unref(m);
sd_bus_unref(a);
sd_bus_unref(b);
sd_memfd_free(f);
return 0;
}

3
src/systemd/sd-bus.h

@ -27,6 +27,7 @@
#include <sd-id128.h>
#include "sd-bus-protocol.h"
#include "sd-memfd.h"
#ifdef __cplusplus
extern "C" {
@ -160,7 +161,9 @@ int sd_bus_message_append(sd_bus_message *m, const char *types, ...);
int sd_bus_message_append_basic(sd_bus_message *m, char type, const void *p);
int sd_bus_message_append_array(sd_bus_message *m, char type, const void *ptr, size_t size);
int sd_bus_message_append_array_space(sd_bus_message *m, char type, size_t size, void **ptr);
int sd_bus_message_append_array_memfd(sd_bus_message *m, char type, sd_memfd *memfd);
int sd_bus_message_append_string_space(sd_bus_message *m, size_t size, char **s);
int sd_bus_message_append_string_memfd(sd_bus_message *m, sd_memfd* memfd);
int sd_bus_message_open_container(sd_bus_message *m, char type, const char *contents);
int sd_bus_message_close_container(sd_bus_message *m);

2
src/systemd/sd-memfd.h

@ -35,6 +35,8 @@ typedef struct sd_memfd sd_memfd;
int sd_memfd_new(sd_memfd **m);
int sd_memfd_make(int fd, sd_memfd **m);
int sd_memfd_new_and_map(sd_memfd **m, size_t sz, void **p);
void sd_memfd_free(sd_memfd *m);
int sd_memfd_get_fd(sd_memfd *m);

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