ubus/ubusd.c
2014-02-18 15:03:53 +01:00

406 lines
8 KiB
C

/*
* Copyright (C) 2011-2014 Felix Fietkau <nbd@openwrt.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License version 2.1
* as published by the Free Software Foundation
*
* This program 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 General Public License for more details.
*/
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/uio.h>
#ifdef FreeBSD
#include <sys/param.h>
#endif
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <libubox/blob.h>
#include <libubox/uloop.h>
#include <libubox/usock.h>
#include <libubox/list.h>
#include "ubusd.h"
static struct ubus_msg_buf *ubus_msg_unshare(struct ubus_msg_buf *ub)
{
ub = realloc(ub, sizeof(*ub) + ub->len);
if (!ub)
return NULL;
ub->refcount = 1;
memcpy(ub + 1, ub->data, ub->len);
ub->data = (void *) (ub + 1);
return ub;
}
static struct ubus_msg_buf *ubus_msg_ref(struct ubus_msg_buf *ub)
{
if (ub->refcount == ~0)
return ubus_msg_unshare(ub);
ub->refcount++;
return ub;
}
struct ubus_msg_buf *ubus_msg_new(void *data, int len, bool shared)
{
struct ubus_msg_buf *ub;
int buflen = sizeof(*ub);
if (!shared)
buflen += len;
ub = calloc(1, buflen);
if (!ub)
return NULL;
ub->fd = -1;
if (shared) {
ub->refcount = ~0;
ub->data = data;
} else {
ub->refcount = 1;
ub->data = (void *) (ub + 1);
if (data)
memcpy(ub + 1, data, len);
}
ub->len = len;
return ub;
}
void ubus_msg_free(struct ubus_msg_buf *ub)
{
switch (ub->refcount) {
case 1:
case ~0:
if (ub->fd >= 0)
close(ub->fd);
free(ub);
break;
default:
ub->refcount--;
break;
}
}
static int ubus_msg_writev(int fd, struct ubus_msg_buf *ub, int offset)
{
static struct iovec iov[2];
static struct {
struct cmsghdr h;
int fd;
} fd_buf = {
.h = {
.cmsg_len = sizeof(fd_buf),
.cmsg_level = SOL_SOCKET,
.cmsg_type = SCM_RIGHTS,
},
};
struct msghdr msghdr = {
.msg_iov = iov,
.msg_iovlen = ARRAY_SIZE(iov),
.msg_control = &fd_buf,
.msg_controllen = sizeof(fd_buf),
};
fd_buf.fd = ub->fd;
if (ub->fd < 0) {
msghdr.msg_control = NULL;
msghdr.msg_controllen = 0;
}
if (offset < sizeof(ub->hdr)) {
iov[0].iov_base = ((char *) &ub->hdr) + offset;
iov[0].iov_len = sizeof(ub->hdr) - offset;
iov[1].iov_base = (char *) ub->data;
iov[1].iov_len = ub->len;
return sendmsg(fd, &msghdr, 0);
} else {
offset -= sizeof(ub->hdr);
return write(fd, ((char *) ub->data) + offset, ub->len - offset);
}
}
static void ubus_msg_enqueue(struct ubus_client *cl, struct ubus_msg_buf *ub)
{
if (cl->tx_queue[cl->txq_tail])
return;
cl->tx_queue[cl->txq_tail] = ubus_msg_ref(ub);
cl->txq_tail = (cl->txq_tail + 1) % ARRAY_SIZE(cl->tx_queue);
}
/* takes the msgbuf reference */
void ubus_msg_send(struct ubus_client *cl, struct ubus_msg_buf *ub, bool free)
{
int written;
if (!cl->tx_queue[cl->txq_cur]) {
written = ubus_msg_writev(cl->sock.fd, ub, 0);
if (written >= ub->len + sizeof(ub->hdr))
goto out;
if (written < 0)
written = 0;
cl->txq_ofs = written;
/* get an event once we can write to the socket again */
uloop_fd_add(&cl->sock, ULOOP_READ | ULOOP_WRITE | ULOOP_EDGE_TRIGGER);
}
ubus_msg_enqueue(cl, ub);
out:
if (free)
ubus_msg_free(ub);
}
static struct ubus_msg_buf *ubus_msg_head(struct ubus_client *cl)
{
return cl->tx_queue[cl->txq_cur];
}
static void ubus_msg_dequeue(struct ubus_client *cl)
{
struct ubus_msg_buf *ub = ubus_msg_head(cl);
if (!ub)
return;
ubus_msg_free(ub);
cl->txq_ofs = 0;
cl->tx_queue[cl->txq_cur] = NULL;
cl->txq_cur = (cl->txq_cur + 1) % ARRAY_SIZE(cl->tx_queue);
}
static void handle_client_disconnect(struct ubus_client *cl)
{
while (ubus_msg_head(cl))
ubus_msg_dequeue(cl);
ubusd_proto_free_client(cl);
if (cl->pending_msg_fd >= 0)
close(cl->pending_msg_fd);
uloop_fd_delete(&cl->sock);
close(cl->sock.fd);
free(cl);
}
static void client_cb(struct uloop_fd *sock, unsigned int events)
{
struct ubus_client *cl = container_of(sock, struct ubus_client, sock);
struct ubus_msg_buf *ub;
static struct iovec iov;
static struct {
struct cmsghdr h;
int fd;
} fd_buf = {
.h = {
.cmsg_type = SCM_RIGHTS,
.cmsg_level = SOL_SOCKET,
.cmsg_len = sizeof(fd_buf),
}
};
struct msghdr msghdr = {
.msg_iov = &iov,
.msg_iovlen = 1,
};
/* first try to tx more pending data */
while ((ub = ubus_msg_head(cl))) {
int written;
written = ubus_msg_writev(sock->fd, ub, cl->txq_ofs);
if (written < 0) {
switch(errno) {
case EINTR:
case EAGAIN:
break;
default:
goto disconnect;
}
break;
}
cl->txq_ofs += written;
if (cl->txq_ofs < ub->len + sizeof(ub->hdr))
break;
ubus_msg_dequeue(cl);
}
/* prevent further ULOOP_WRITE events if we don't have data
* to send anymore */
if (!ubus_msg_head(cl) && (events & ULOOP_WRITE))
uloop_fd_add(sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
retry:
if (!sock->eof && cl->pending_msg_offset < sizeof(cl->hdrbuf)) {
int offset = cl->pending_msg_offset;
int bytes;
fd_buf.fd = -1;
iov.iov_base = &cl->hdrbuf + offset;
iov.iov_len = sizeof(cl->hdrbuf) - offset;
if (cl->pending_msg_fd < 0) {
msghdr.msg_control = &fd_buf;
msghdr.msg_controllen = sizeof(fd_buf);
} else {
msghdr.msg_control = NULL;
msghdr.msg_controllen = 0;
}
bytes = recvmsg(sock->fd, &msghdr, 0);
if (bytes < 0)
goto out;
if (fd_buf.fd >= 0)
cl->pending_msg_fd = fd_buf.fd;
cl->pending_msg_offset += bytes;
if (cl->pending_msg_offset < sizeof(cl->hdrbuf))
goto out;
if (blob_pad_len(&cl->hdrbuf.data) > UBUS_MAX_MSGLEN)
goto disconnect;
cl->pending_msg = ubus_msg_new(NULL, blob_raw_len(&cl->hdrbuf.data), false);
if (!cl->pending_msg)
goto disconnect;
memcpy(&cl->pending_msg->hdr, &cl->hdrbuf.hdr, sizeof(cl->hdrbuf.hdr));
memcpy(cl->pending_msg->data, &cl->hdrbuf.data, sizeof(cl->hdrbuf.data));
}
ub = cl->pending_msg;
if (ub) {
int offset = cl->pending_msg_offset - sizeof(ub->hdr);
int len = blob_raw_len(ub->data) - offset;
int bytes = 0;
if (len > 0) {
bytes = read(sock->fd, (char *) ub->data + offset, len);
if (bytes <= 0)
goto out;
}
if (bytes < len) {
cl->pending_msg_offset += bytes;
goto out;
}
/* accept message */
ub->fd = cl->pending_msg_fd;
cl->pending_msg_fd = -1;
cl->pending_msg_offset = 0;
cl->pending_msg = NULL;
ubusd_proto_receive_message(cl, ub);
goto retry;
}
out:
if (!sock->eof || ubus_msg_head(cl))
return;
disconnect:
handle_client_disconnect(cl);
}
static bool get_next_connection(int fd)
{
struct ubus_client *cl;
int client_fd;
client_fd = accept(fd, NULL, 0);
if (client_fd < 0) {
switch (errno) {
case ECONNABORTED:
case EINTR:
return true;
default:
return false;
}
}
cl = ubusd_proto_new_client(client_fd, client_cb);
if (cl)
uloop_fd_add(&cl->sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
else
close(client_fd);
return true;
}
static void server_cb(struct uloop_fd *fd, unsigned int events)
{
bool next;
do {
next = get_next_connection(fd->fd);
} while (next);
}
static struct uloop_fd server_fd = {
.cb = server_cb,
};
static int usage(const char *progname)
{
fprintf(stderr, "Usage: %s [<options>]\n"
"Options: \n"
" -s <socket>: Set the unix domain socket to listen on\n"
"\n", progname);
return 1;
}
int main(int argc, char **argv)
{
const char *ubus_socket = UBUS_UNIX_SOCKET;
int ret = 0;
int ch;
signal(SIGPIPE, SIG_IGN);
uloop_init();
while ((ch = getopt(argc, argv, "s:")) != -1) {
switch (ch) {
case 's':
ubus_socket = optarg;
break;
default:
return usage(argv[0]);
}
}
unlink(ubus_socket);
umask(0177);
server_fd.fd = usock(USOCK_UNIX | USOCK_SERVER | USOCK_NONBLOCK, ubus_socket, NULL);
if (server_fd.fd < 0) {
perror("usock");
ret = -1;
goto out;
}
uloop_fd_add(&server_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
uloop_run();
unlink(ubus_socket);
out:
uloop_done();
return ret;
}