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bus: fall back to readv/writev if recvmsg/sendmsg don't work

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This commit is contained in:
Lennart Poettering 2013-03-31 20:19:18 +02:00
parent e82c950997
commit 15d5af8145
3 changed files with 136 additions and 91 deletions
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2
src/libsystemd-bus/bus-internal.h
View File

@ -83,6 +83,8 @@ struct sd_bus {
bool ucred_valid:1;
bool is_server:1;
bool anonymous_auth:1;
bool prefer_readv:1;
bool prefer_writev:1;
void *rbuffer;
size_t rbuffer_size;

223
src/libsystemd-bus/bus-socket.c
View File

@ -75,7 +75,6 @@ bool bus_socket_auth_needs_write(sd_bus *b) {
}
static int bus_socket_write_auth(sd_bus *b) {
struct msghdr mh;
ssize_t k;
assert(b);
@ -84,16 +83,26 @@ static int bus_socket_write_auth(sd_bus *b) {
if (!bus_socket_auth_needs_write(b))
return 0;
zero(mh);
mh.msg_iov = b->auth_iovec + b->auth_index;
mh.msg_iovlen = ELEMENTSOF(b->auth_iovec) - b->auth_index;
if (b->prefer_writev)
k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index);
else {
struct msghdr mh;
zero(mh);
mh.msg_iov = b->auth_iovec + b->auth_index;
mh.msg_iovlen = ELEMENTSOF(b->auth_iovec) - b->auth_index;
k = sendmsg(b->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL);
if (k < 0 && errno == ENOTSOCK) {
b->prefer_writev = true;
k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index);
}
}
k = sendmsg(b->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL);
if (k < 0)
return errno == EAGAIN ? 0 : -errno;
iovec_advance(b->auth_iovec, &b->auth_index, (size_t) k);
return 1;
}
@ -431,6 +440,7 @@ static int bus_socket_read_auth(sd_bus *b) {
CMSG_SPACE(NAME_MAX)]; /*selinux label */
} control;
struct cmsghdr *cmsg;
bool handle_cmsg = false;
assert(b);
assert(b->state == BUS_AUTHENTICATING);
@ -457,13 +467,22 @@ static int bus_socket_read_auth(sd_bus *b) {
iov.iov_base = (uint8_t*) b->rbuffer + b->rbuffer_size;
iov.iov_len = n - b->rbuffer_size;
zero(mh);
mh.msg_iov = &iov;
mh.msg_iovlen = 1;
mh.msg_control = &control;
mh.msg_controllen = sizeof(control);
if (b->prefer_readv)
k = readv(b->input_fd, &iov, 1);
else {
zero(mh);
mh.msg_iov = &iov;
mh.msg_iovlen = 1;
mh.msg_control = &control;
mh.msg_controllen = sizeof(control);
k = recvmsg(b->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC);
k = recvmsg(b->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC);
if (k < 0 && errno == ENOTSOCK) {
b->prefer_readv = true;
k = readv(b->input_fd, &iov, 1);
} else
handle_cmsg = true;
}
if (k < 0)
return errno == EAGAIN ? 0 : -errno;
if (k == 0)
@ -471,32 +490,34 @@ static int bus_socket_read_auth(sd_bus *b) {
b->rbuffer_size += k;
for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) {
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_RIGHTS) {
int j;
if (handle_cmsg) {
for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) {
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_RIGHTS) {
int j;
/* Whut? We received fds during the auth
* protocol? Somebody is playing games with
* us. Close them all, and fail */
j = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
close_many((int*) CMSG_DATA(cmsg), j);
return -EIO;
/* Whut? We received fds during the auth
* protocol? Somebody is playing games with
* us. Close them all, and fail */
j = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
close_many((int*) CMSG_DATA(cmsg), j);
return -EIO;
} else if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_CREDENTIALS &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
} else if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_CREDENTIALS &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
memcpy(&b->ucred, CMSG_DATA(cmsg), sizeof(struct ucred));
b->ucred_valid = true;
memcpy(&b->ucred, CMSG_DATA(cmsg), sizeof(struct ucred));
b->ucred_valid = true;
} else if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_SECURITY) {
} else if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_SECURITY) {
size_t l;
l = cmsg->cmsg_len - CMSG_LEN(0);
memcpy(&b->label, CMSG_DATA(cmsg), l);
b->label[l] = 0;
size_t l;
l = cmsg->cmsg_len - CMSG_LEN(0);
memcpy(&b->label, CMSG_DATA(cmsg), l);
b->label[l] = 0;
}
}
}
@ -687,7 +708,6 @@ int bus_socket_take_fd(sd_bus *b) {
}
int bus_socket_write_message(sd_bus *bus, sd_bus_message *m, size_t *idx) {
struct msghdr mh;
struct iovec *iov;
ssize_t k;
size_t n;
@ -700,18 +720,6 @@ int bus_socket_write_message(sd_bus *bus, sd_bus_message *m, size_t *idx) {
if (*idx >= m->size)
return 0;
zero(mh);
if (m->n_fds > 0) {
struct cmsghdr *control;
control = alloca(CMSG_SPACE(sizeof(int) * m->n_fds));
mh.msg_control = control;
control->cmsg_level = SOL_SOCKET;
control->cmsg_type = SCM_RIGHTS;
mh.msg_controllen = control->cmsg_len = CMSG_LEN(sizeof(int) * m->n_fds);
memcpy(CMSG_DATA(control), m->fds, sizeof(int) * m->n_fds);
}
n = m->n_iovec * sizeof(struct iovec);
iov = alloca(n);
@ -720,10 +728,33 @@ int bus_socket_write_message(sd_bus *bus, sd_bus_message *m, size_t *idx) {
j = 0;
iovec_advance(iov, &j, *idx);
mh.msg_iov = iov;
mh.msg_iovlen = m->n_iovec;
if (bus->prefer_writev)
k = writev(bus->output_fd, iov, m->n_iovec);
else {
struct msghdr mh;
zero(mh);
if (m->n_fds > 0) {
struct cmsghdr *control;
control = alloca(CMSG_SPACE(sizeof(int) * m->n_fds));
mh.msg_control = control;
control->cmsg_level = SOL_SOCKET;
control->cmsg_type = SCM_RIGHTS;
mh.msg_controllen = control->cmsg_len = CMSG_LEN(sizeof(int) * m->n_fds);
memcpy(CMSG_DATA(control), m->fds, sizeof(int) * m->n_fds);
}
mh.msg_iov = iov;
mh.msg_iovlen = m->n_iovec;
k = sendmsg(bus->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL);
if (k < 0 && errno == ENOTSOCK) {
bus->prefer_writev = true;
k = writev(bus->output_fd, iov, m->n_iovec);
}
}
k = sendmsg(bus->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL);
if (k < 0)
return errno == EAGAIN ? 0 : -errno;
@ -835,6 +866,7 @@ int bus_socket_read_message(sd_bus *bus, sd_bus_message **m) {
CMSG_SPACE(NAME_MAX)]; /*selinux label */
} control;
struct cmsghdr *cmsg;
bool handle_cmsg;
assert(bus);
assert(m);
@ -857,13 +889,22 @@ int bus_socket_read_message(sd_bus *bus, sd_bus_message **m) {
iov.iov_base = (uint8_t*) bus->rbuffer + bus->rbuffer_size;
iov.iov_len = need - bus->rbuffer_size;
zero(mh);
mh.msg_iov = &iov;
mh.msg_iovlen = 1;
mh.msg_control = &control;
mh.msg_controllen = sizeof(control);
if (bus->prefer_readv)
k = readv(bus->input_fd, &iov, 1);
else {
zero(mh);
mh.msg_iov = &iov;
mh.msg_iovlen = 1;
mh.msg_control = &control;
mh.msg_controllen = sizeof(control);
k = recvmsg(bus->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC);
k = recvmsg(bus->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC);
if (k < 0 && errno == ENOTSOCK) {
bus->prefer_readv = true;
k = readv(bus->input_fd, &iov, 1);
} else
handle_cmsg = true;
}
if (k < 0)
return errno == EAGAIN ? 0 : -errno;
if (k == 0)
@ -871,45 +912,47 @@ int bus_socket_read_message(sd_bus *bus, sd_bus_message **m) {
bus->rbuffer_size += k;
for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) {
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_RIGHTS) {
int n, *f;
if (handle_cmsg) {
for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) {
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_RIGHTS) {
int n, *f;
n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
if (!bus->can_fds) {
/* Whut? We received fds but this
* isn't actually enabled? Close them,
* and fail */
if (!bus->can_fds) {
/* Whut? We received fds but this
* isn't actually enabled? Close them,
* and fail */
close_many((int*) CMSG_DATA(cmsg), n);
return -EIO;
close_many((int*) CMSG_DATA(cmsg), n);
return -EIO;
}
f = realloc(bus->fds, sizeof(int) + (bus->n_fds + n));
if (!f) {
close_many((int*) CMSG_DATA(cmsg), n);
return -ENOMEM;
}
memcpy(f + bus->n_fds, CMSG_DATA(cmsg), n * sizeof(int));
bus->fds = f;
bus->n_fds += n;
} else if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_CREDENTIALS &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
memcpy(&bus->ucred, CMSG_DATA(cmsg), sizeof(struct ucred));
bus->ucred_valid = true;
} else if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_SECURITY) {
size_t l;
l = cmsg->cmsg_len - CMSG_LEN(0);
memcpy(&bus->label, CMSG_DATA(cmsg), l);
bus->label[l] = 0;
}
f = realloc(bus->fds, sizeof(int) + (bus->n_fds + n));
if (!f) {
close_many((int*) CMSG_DATA(cmsg), n);
return -ENOMEM;
}
memcpy(f + bus->n_fds, CMSG_DATA(cmsg), n * sizeof(int));
bus->fds = f;
bus->n_fds += n;
} else if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_CREDENTIALS &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
memcpy(&bus->ucred, CMSG_DATA(cmsg), sizeof(struct ucred));
bus->ucred_valid = true;
} else if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_SECURITY) {
size_t l;
l = cmsg->cmsg_len - CMSG_LEN(0);
memcpy(&bus->label, CMSG_DATA(cmsg), l);
bus->label[l] = 0;
}
}

2
src/systemd/sd-bus.h
View File

@ -57,7 +57,7 @@ int sd_bus_open_user(sd_bus **ret);
int sd_bus_new(sd_bus **ret);
int sd_bus_set_address(sd_bus *bus, const char *address);
int sd_bus_set_fd(sd_bus *bus, int fd);
int sd_bus_set_fd(sd_bus *bus, int input_fd, int output_fd);
int sd_bus_set_exec(sd_bus *bus, const char *path, char *const argv[]);
int sd_bus_set_bus_client(sd_bus *bus, int b);
int sd_bus_set_server(sd_bus *bus, int b, sd_id128_t server_id);