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/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_channel.h>
ngx_int_t
ngx_write_channel(ngx_socket_t s, ngx_channel_t *ch, size_t size,
ngx_log_t *log)
{
ssize_t n;
ngx_err_t err;
struct iovec iov[1];
struct msghdr msg;
#if (NGX_HAVE_MSGHDR_MSG_CONTROL)
union {
struct cmsghdr cm;
char space[CMSG_SPACE(sizeof(int))];
} cmsg;
if (ch->fd == -1) {
msg.msg_control = NULL;
msg.msg_controllen = 0;
} else {
msg.msg_control = (caddr_t) &cmsg;
msg.msg_controllen = sizeof(cmsg);
ngx_memzero(&cmsg, sizeof(cmsg));
cmsg.cm.cmsg_len = CMSG_LEN(sizeof(int));
cmsg.cm.cmsg_level = SOL_SOCKET;
cmsg.cm.cmsg_type = SCM_RIGHTS;
/*
* We have to use ngx_memcpy() instead of simple
* *(int *) CMSG_DATA(&cmsg.cm) = ch->fd;
* because some gcc 4.4 with -O2/3/s optimization issues the warning:
* dereferencing type-punned pointer will break strict-aliasing rules
*
* Fortunately, gcc with -O1 compiles this ngx_memcpy()
* in the same simple assignment as in the code above
*/
ngx_memcpy(CMSG_DATA(&cmsg.cm), &ch->fd, sizeof(int));
}
msg.msg_flags = 0;
#else
if (ch->fd == -1) {
msg.msg_accrights = NULL;
msg.msg_accrightslen = 0;
} else {
msg.msg_accrights = (caddr_t) &ch->fd;
msg.msg_accrightslen = sizeof(int);
}
#endif
iov[0].iov_base = (char *) ch;
iov[0].iov_len = size;
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_iov = iov;
msg.msg_iovlen = 1;
n = sendmsg(s, &msg, 0);
if (n == -1) {
err = ngx_errno;
if (err == NGX_EAGAIN) {
return NGX_AGAIN;
}
ngx_log_error(NGX_LOG_ALERT, log, err, "sendmsg() failed");
return NGX_ERROR;
}
return NGX_OK;
}
ngx_int_t
ngx_read_channel(ngx_socket_t s, ngx_channel_t *ch, size_t size, ngx_log_t *log)
{
ssize_t n;
ngx_err_t err;
struct iovec iov[1];
struct msghdr msg;
#if (NGX_HAVE_MSGHDR_MSG_CONTROL)
union {
struct cmsghdr cm;
char space[CMSG_SPACE(sizeof(int))];
} cmsg;
#else
int fd;
#endif
iov[0].iov_base = (char *) ch;
iov[0].iov_len = size;
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_iov = iov;
msg.msg_iovlen = 1;
#if (NGX_HAVE_MSGHDR_MSG_CONTROL)
msg.msg_control = (caddr_t) &cmsg;
msg.msg_controllen = sizeof(cmsg);
#else
msg.msg_accrights = (caddr_t) &fd;
msg.msg_accrightslen = sizeof(int);
#endif
n = recvmsg(s, &msg, 0);
if (n == -1) {
err = ngx_errno;
if (err == NGX_EAGAIN) {
return NGX_AGAIN;
}
ngx_log_error(NGX_LOG_ALERT, log, err, "recvmsg() failed");
return NGX_ERROR;
}
if (n == 0) {
ngx_log_debug0(NGX_LOG_DEBUG_CORE, log, 0, "recvmsg() returned zero");
return NGX_ERROR;
}
if ((size_t) n < sizeof(ngx_channel_t)) {
ngx_log_error(NGX_LOG_ALERT, log, 0,
"recvmsg() returned not enough data: %z", n);
return NGX_ERROR;
}
#if (NGX_HAVE_MSGHDR_MSG_CONTROL)
if (ch->command == NGX_CMD_OPEN_CHANNEL) {
if (cmsg.cm.cmsg_len < (socklen_t) CMSG_LEN(sizeof(int))) {
ngx_log_error(NGX_LOG_ALERT, log, 0,
"recvmsg() returned too small ancillary data");
return NGX_ERROR;
}
if (cmsg.cm.cmsg_level != SOL_SOCKET || cmsg.cm.cmsg_type != SCM_RIGHTS)
{
ngx_log_error(NGX_LOG_ALERT, log, 0,
"recvmsg() returned invalid ancillary data "
"level %d or type %d",
cmsg.cm.cmsg_level, cmsg.cm.cmsg_type);
return NGX_ERROR;
}
/* ch->fd = *(int *) CMSG_DATA(&cmsg.cm); */
ngx_memcpy(&ch->fd, CMSG_DATA(&cmsg.cm), sizeof(int));
}
if (msg.msg_flags & (MSG_TRUNC|MSG_CTRUNC)) {
ngx_log_error(NGX_LOG_ALERT, log, 0,
"recvmsg() truncated data");
}
#else
if (ch->command == NGX_CMD_OPEN_CHANNEL) {
if (msg.msg_accrightslen != sizeof(int)) {
ngx_log_error(NGX_LOG_ALERT, log, 0,
"recvmsg() returned no ancillary data");
return NGX_ERROR;
}
ch->fd = fd;
}
#endif
return n;
}
ngx_int_t
ngx_add_channel_event(ngx_cycle_t *cycle, ngx_fd_t fd, ngx_int_t event,
ngx_event_handler_pt handler)
{
ngx_event_t *ev, *rev, *wev;
ngx_connection_t *c;
c = ngx_get_connection(fd, cycle->log);
if (c == NULL) {
return NGX_ERROR;
}
c->pool = cycle->pool;
rev = c->read;
wev = c->write;
rev->log = cycle->log;
wev->log = cycle->log;
rev->channel = 1;
wev->channel = 1;
ev = (event == NGX_READ_EVENT) ? rev : wev;
ev->handler = handler;
if (ngx_add_conn && (ngx_event_flags & NGX_USE_EPOLL_EVENT) == 0) {
if (ngx_add_conn(c) == NGX_ERROR) {
ngx_free_connection(c);
return NGX_ERROR;
}
} else {
if (ngx_add_event(ev, event, 0) == NGX_ERROR) {
ngx_free_connection(c);
return NGX_ERROR;
}
}
return NGX_OK;
}
void
ngx_close_channel(ngx_fd_t *fd, ngx_log_t *log)
{
if (close(fd[0]) == -1) {
ngx_log_error(NGX_LOG_ALERT, log, ngx_errno, "close() channel failed");
}
if (close(fd[1]) == -1) {
ngx_log_error(NGX_LOG_ALERT, log, ngx_errno, "close() channel failed");
}
}
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