monero/external/unbound/util/tube.c

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2014-10-05 21:44:31 +00:00
/*
* util/tube.c - pipe service
*
* Copyright (c) 2008, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains pipe service functions.
*/
#include "config.h"
#include "util/tube.h"
#include "util/log.h"
#include "util/net_help.h"
#include "util/netevent.h"
#include "util/fptr_wlist.h"
#ifndef USE_WINSOCK
/* on unix */
#ifndef HAVE_SOCKETPAIR
/** no socketpair() available, like on Minix 3.1.7, use pipe */
#define socketpair(f, t, p, sv) pipe(sv)
#endif /* HAVE_SOCKETPAIR */
struct tube* tube_create(void)
{
struct tube* tube = (struct tube*)calloc(1, sizeof(*tube));
int sv[2];
if(!tube) {
int err = errno;
log_err("tube_create: out of memory");
errno = err;
return NULL;
}
tube->sr = -1;
tube->sw = -1;
if(socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == -1) {
int err = errno;
log_err("socketpair: %s", strerror(errno));
free(tube);
errno = err;
return NULL;
}
tube->sr = sv[0];
tube->sw = sv[1];
if(!fd_set_nonblock(tube->sr) || !fd_set_nonblock(tube->sw)) {
int err = errno;
log_err("tube: cannot set nonblocking");
tube_delete(tube);
errno = err;
return NULL;
}
return tube;
}
void tube_delete(struct tube* tube)
{
if(!tube) return;
tube_remove_bg_listen(tube);
tube_remove_bg_write(tube);
/* close fds after deleting commpoints, to be sure.
* Also epoll does not like closing fd before event_del */
tube_close_read(tube);
tube_close_write(tube);
free(tube);
}
void tube_close_read(struct tube* tube)
{
if(tube->sr != -1) {
close(tube->sr);
tube->sr = -1;
}
}
void tube_close_write(struct tube* tube)
{
if(tube->sw != -1) {
close(tube->sw);
tube->sw = -1;
}
}
void tube_remove_bg_listen(struct tube* tube)
{
if(tube->listen_com) {
comm_point_delete(tube->listen_com);
tube->listen_com = NULL;
}
if(tube->cmd_msg) {
free(tube->cmd_msg);
tube->cmd_msg = NULL;
}
}
void tube_remove_bg_write(struct tube* tube)
{
if(tube->res_com) {
comm_point_delete(tube->res_com);
tube->res_com = NULL;
}
if(tube->res_list) {
struct tube_res_list* np, *p = tube->res_list;
tube->res_list = NULL;
tube->res_last = NULL;
while(p) {
np = p->next;
free(p->buf);
free(p);
p = np;
}
}
}
int
tube_handle_listen(struct comm_point* c, void* arg, int error,
struct comm_reply* ATTR_UNUSED(reply_info))
{
struct tube* tube = (struct tube*)arg;
ssize_t r;
if(error != NETEVENT_NOERROR) {
fptr_ok(fptr_whitelist_tube_listen(tube->listen_cb));
(*tube->listen_cb)(tube, NULL, 0, error, tube->listen_arg);
return 0;
}
if(tube->cmd_read < sizeof(tube->cmd_len)) {
/* complete reading the length of control msg */
r = read(c->fd, ((uint8_t*)&tube->cmd_len) + tube->cmd_read,
sizeof(tube->cmd_len) - tube->cmd_read);
if(r==0) {
/* error has happened or */
/* parent closed pipe, must have exited somehow */
fptr_ok(fptr_whitelist_tube_listen(tube->listen_cb));
(*tube->listen_cb)(tube, NULL, 0, NETEVENT_CLOSED,
tube->listen_arg);
return 0;
}
if(r==-1) {
if(errno != EAGAIN && errno != EINTR) {
log_err("rpipe error: %s", strerror(errno));
}
/* nothing to read now, try later */
return 0;
}
tube->cmd_read += r;
if(tube->cmd_read < sizeof(tube->cmd_len)) {
/* not complete, try later */
return 0;
}
tube->cmd_msg = (uint8_t*)calloc(1, tube->cmd_len);
if(!tube->cmd_msg) {
log_err("malloc failure");
tube->cmd_read = 0;
return 0;
}
}
/* cmd_len has been read, read remainder */
r = read(c->fd, tube->cmd_msg+tube->cmd_read-sizeof(tube->cmd_len),
tube->cmd_len - (tube->cmd_read - sizeof(tube->cmd_len)));
if(r==0) {
/* error has happened or */
/* parent closed pipe, must have exited somehow */
fptr_ok(fptr_whitelist_tube_listen(tube->listen_cb));
(*tube->listen_cb)(tube, NULL, 0, NETEVENT_CLOSED,
tube->listen_arg);
return 0;
}
if(r==-1) {
/* nothing to read now, try later */
if(errno != EAGAIN && errno != EINTR) {
log_err("rpipe error: %s", strerror(errno));
}
return 0;
}
tube->cmd_read += r;
if(tube->cmd_read < sizeof(tube->cmd_len) + tube->cmd_len) {
/* not complete, try later */
return 0;
}
tube->cmd_read = 0;
fptr_ok(fptr_whitelist_tube_listen(tube->listen_cb));
(*tube->listen_cb)(tube, tube->cmd_msg, tube->cmd_len,
NETEVENT_NOERROR, tube->listen_arg);
/* also frees the buf */
tube->cmd_msg = NULL;
return 0;
}
int
tube_handle_write(struct comm_point* c, void* arg, int error,
struct comm_reply* ATTR_UNUSED(reply_info))
{
struct tube* tube = (struct tube*)arg;
struct tube_res_list* item = tube->res_list;
ssize_t r;
if(error != NETEVENT_NOERROR) {
log_err("tube_handle_write net error %d", error);
return 0;
}
if(!item) {
comm_point_stop_listening(c);
return 0;
}
if(tube->res_write < sizeof(item->len)) {
r = write(c->fd, ((uint8_t*)&item->len) + tube->res_write,
sizeof(item->len) - tube->res_write);
if(r == -1) {
if(errno != EAGAIN && errno != EINTR) {
log_err("wpipe error: %s", strerror(errno));
}
return 0; /* try again later */
}
if(r == 0) {
/* error on pipe, must have exited somehow */
/* cannot signal this to pipe user */
return 0;
}
tube->res_write += r;
if(tube->res_write < sizeof(item->len))
return 0;
}
r = write(c->fd, item->buf + tube->res_write - sizeof(item->len),
item->len - (tube->res_write - sizeof(item->len)));
if(r == -1) {
if(errno != EAGAIN && errno != EINTR) {
log_err("wpipe error: %s", strerror(errno));
}
return 0; /* try again later */
}
if(r == 0) {
/* error on pipe, must have exited somehow */
/* cannot signal this to pipe user */
return 0;
}
tube->res_write += r;
if(tube->res_write < sizeof(item->len) + item->len)
return 0;
/* done this result, remove it */
free(item->buf);
item->buf = NULL;
tube->res_list = tube->res_list->next;
free(item);
if(!tube->res_list) {
tube->res_last = NULL;
comm_point_stop_listening(c);
}
tube->res_write = 0;
return 0;
}
int tube_write_msg(struct tube* tube, uint8_t* buf, uint32_t len,
int nonblock)
{
ssize_t r, d;
int fd = tube->sw;
/* test */
if(nonblock) {
r = write(fd, &len, sizeof(len));
if(r == -1) {
if(errno==EINTR || errno==EAGAIN)
return -1;
log_err("tube msg write failed: %s", strerror(errno));
return -1; /* can still continue, perhaps */
}
} else r = 0;
if(!fd_set_block(fd))
return 0;
/* write remainder */
d = r;
while(d != (ssize_t)sizeof(len)) {
if((r=write(fd, ((char*)&len)+d, sizeof(len)-d)) == -1) {
log_err("tube msg write failed: %s", strerror(errno));
(void)fd_set_nonblock(fd);
return 0;
}
d += r;
}
d = 0;
while(d != (ssize_t)len) {
if((r=write(fd, buf+d, len-d)) == -1) {
log_err("tube msg write failed: %s", strerror(errno));
(void)fd_set_nonblock(fd);
return 0;
}
d += r;
}
if(!fd_set_nonblock(fd))
return 0;
return 1;
}
int tube_read_msg(struct tube* tube, uint8_t** buf, uint32_t* len,
int nonblock)
{
ssize_t r, d;
int fd = tube->sr;
/* test */
*len = 0;
if(nonblock) {
r = read(fd, len, sizeof(*len));
if(r == -1) {
if(errno==EINTR || errno==EAGAIN)
return -1;
log_err("tube msg read failed: %s", strerror(errno));
return -1; /* we can still continue, perhaps */
}
if(r == 0) /* EOF */
return 0;
} else r = 0;
if(!fd_set_block(fd))
return 0;
/* read remainder */
d = r;
while(d != (ssize_t)sizeof(*len)) {
if((r=read(fd, ((char*)len)+d, sizeof(*len)-d)) == -1) {
log_err("tube msg read failed: %s", strerror(errno));
(void)fd_set_nonblock(fd);
return 0;
}
if(r == 0) /* EOF */ {
(void)fd_set_nonblock(fd);
return 0;
}
d += r;
}
log_assert(*len < 65536*2);
*buf = (uint8_t*)malloc(*len);
if(!*buf) {
log_err("tube read out of memory");
(void)fd_set_nonblock(fd);
return 0;
}
d = 0;
while(d < (ssize_t)*len) {
if((r=read(fd, (*buf)+d, (size_t)((ssize_t)*len)-d)) == -1) {
log_err("tube msg read failed: %s", strerror(errno));
(void)fd_set_nonblock(fd);
free(*buf);
return 0;
}
if(r == 0) { /* EOF */
(void)fd_set_nonblock(fd);
free(*buf);
return 0;
}
d += r;
}
if(!fd_set_nonblock(fd)) {
free(*buf);
return 0;
}
return 1;
}
/** perform a select() on the fd */
static int
pollit(int fd, struct timeval* t)
{
fd_set r;
#ifndef S_SPLINT_S
FD_ZERO(&r);
FD_SET(FD_SET_T fd, &r);
#endif
if(select(fd+1, &r, NULL, NULL, t) == -1) {
return 0;
}
errno = 0;
return (int)(FD_ISSET(fd, &r));
}
int tube_poll(struct tube* tube)
{
struct timeval t;
memset(&t, 0, sizeof(t));
return pollit(tube->sr, &t);
}
int tube_wait(struct tube* tube)
{
return pollit(tube->sr, NULL);
}
int tube_read_fd(struct tube* tube)
{
return tube->sr;
}
int tube_setup_bg_listen(struct tube* tube, struct comm_base* base,
tube_callback_t* cb, void* arg)
{
tube->listen_cb = cb;
tube->listen_arg = arg;
if(!(tube->listen_com = comm_point_create_raw(base, tube->sr,
0, tube_handle_listen, tube))) {
int err = errno;
log_err("tube_setup_bg_l: commpoint creation failed");
errno = err;
return 0;
}
return 1;
}
int tube_setup_bg_write(struct tube* tube, struct comm_base* base)
{
if(!(tube->res_com = comm_point_create_raw(base, tube->sw,
1, tube_handle_write, tube))) {
int err = errno;
log_err("tube_setup_bg_w: commpoint creation failed");
errno = err;
return 0;
}
return 1;
}
int tube_queue_item(struct tube* tube, uint8_t* msg, size_t len)
{
struct tube_res_list* item =
(struct tube_res_list*)malloc(sizeof(*item));
if(!item) {
free(msg);
log_err("out of memory for async answer");
return 0;
}
item->buf = msg;
item->len = len;
item->next = NULL;
/* add at back of list, since the first one may be partially written */
if(tube->res_last)
tube->res_last->next = item;
else tube->res_list = item;
tube->res_last = item;
if(tube->res_list == tube->res_last) {
/* first added item, start the write process */
comm_point_start_listening(tube->res_com, -1, -1);
}
return 1;
}
void tube_handle_signal(int ATTR_UNUSED(fd), short ATTR_UNUSED(events),
void* ATTR_UNUSED(arg))
{
log_assert(0);
}
#else /* USE_WINSOCK */
/* on windows */
struct tube* tube_create(void)
{
/* windows does not have forks like unix, so we only support
* threads on windows. And thus the pipe need only connect
* threads. We use a mutex and a list of datagrams. */
struct tube* tube = (struct tube*)calloc(1, sizeof(*tube));
if(!tube) {
int err = errno;
log_err("tube_create: out of memory");
errno = err;
return NULL;
}
tube->event = WSACreateEvent();
if(tube->event == WSA_INVALID_EVENT) {
free(tube);
log_err("WSACreateEvent: %s", wsa_strerror(WSAGetLastError()));
}
if(!WSAResetEvent(tube->event)) {
log_err("WSAResetEvent: %s", wsa_strerror(WSAGetLastError()));
}
lock_basic_init(&tube->res_lock);
verbose(VERB_ALGO, "tube created");
return tube;
}
void tube_delete(struct tube* tube)
{
if(!tube) return;
tube_remove_bg_listen(tube);
tube_remove_bg_write(tube);
tube_close_read(tube);
tube_close_write(tube);
if(!WSACloseEvent(tube->event))
log_err("WSACloseEvent: %s", wsa_strerror(WSAGetLastError()));
lock_basic_destroy(&tube->res_lock);
verbose(VERB_ALGO, "tube deleted");
free(tube);
}
void tube_close_read(struct tube* ATTR_UNUSED(tube))
{
verbose(VERB_ALGO, "tube close_read");
}
void tube_close_write(struct tube* ATTR_UNUSED(tube))
{
verbose(VERB_ALGO, "tube close_write");
/* wake up waiting reader with an empty queue */
if(!WSASetEvent(tube->event)) {
log_err("WSASetEvent: %s", wsa_strerror(WSAGetLastError()));
}
}
void tube_remove_bg_listen(struct tube* tube)
{
verbose(VERB_ALGO, "tube remove_bg_listen");
winsock_unregister_wsaevent(&tube->ev_listen);
}
void tube_remove_bg_write(struct tube* tube)
{
verbose(VERB_ALGO, "tube remove_bg_write");
if(tube->res_list) {
struct tube_res_list* np, *p = tube->res_list;
tube->res_list = NULL;
tube->res_last = NULL;
while(p) {
np = p->next;
free(p->buf);
free(p);
p = np;
}
}
}
int tube_write_msg(struct tube* tube, uint8_t* buf, uint32_t len,
int ATTR_UNUSED(nonblock))
{
uint8_t* a;
verbose(VERB_ALGO, "tube write_msg len %d", (int)len);
a = (uint8_t*)memdup(buf, len);
if(!a) {
log_err("out of memory in tube_write_msg");
return 0;
}
/* always nonblocking, this pipe cannot get full */
return tube_queue_item(tube, a, len);
}
int tube_read_msg(struct tube* tube, uint8_t** buf, uint32_t* len,
int nonblock)
{
struct tube_res_list* item = NULL;
verbose(VERB_ALGO, "tube read_msg %s", nonblock?"nonblock":"blocking");
*buf = NULL;
if(!tube_poll(tube)) {
verbose(VERB_ALGO, "tube read_msg nodata");
/* nothing ready right now, wait if we want to */
if(nonblock)
return -1; /* would block waiting for items */
if(!tube_wait(tube))
return 0;
}
lock_basic_lock(&tube->res_lock);
if(tube->res_list) {
item = tube->res_list;
tube->res_list = item->next;
if(tube->res_last == item) {
/* the list is now empty */
tube->res_last = NULL;
verbose(VERB_ALGO, "tube read_msg lastdata");
if(!WSAResetEvent(tube->event)) {
log_err("WSAResetEvent: %s",
wsa_strerror(WSAGetLastError()));
}
}
}
lock_basic_unlock(&tube->res_lock);
if(!item)
return 0; /* would block waiting for items */
*buf = item->buf;
*len = item->len;
free(item);
verbose(VERB_ALGO, "tube read_msg len %d", (int)*len);
return 1;
}
int tube_poll(struct tube* tube)
{
struct tube_res_list* item = NULL;
lock_basic_lock(&tube->res_lock);
item = tube->res_list;
lock_basic_unlock(&tube->res_lock);
if(item)
return 1;
return 0;
}
int tube_wait(struct tube* tube)
{
/* block on eventhandle */
DWORD res = WSAWaitForMultipleEvents(
1 /* one event in array */,
&tube->event /* the event to wait for, our pipe signal */,
0 /* wait for all events is false */,
WSA_INFINITE /* wait, no timeout */,
0 /* we are not alertable for IO completion routines */
);
if(res == WSA_WAIT_TIMEOUT) {
return 0;
}
if(res == WSA_WAIT_IO_COMPLETION) {
/* a bit unexpected, since we were not alertable */
return 0;
}
return 1;
}
int tube_read_fd(struct tube* ATTR_UNUSED(tube))
{
/* nothing sensible on Windows */
return -1;
}
int
tube_handle_listen(struct comm_point* ATTR_UNUSED(c), void* ATTR_UNUSED(arg),
int ATTR_UNUSED(error), struct comm_reply* ATTR_UNUSED(reply_info))
{
log_assert(0);
return 0;
}
int
tube_handle_write(struct comm_point* ATTR_UNUSED(c), void* ATTR_UNUSED(arg),
int ATTR_UNUSED(error), struct comm_reply* ATTR_UNUSED(reply_info))
{
log_assert(0);
return 0;
}
int tube_setup_bg_listen(struct tube* tube, struct comm_base* base,
tube_callback_t* cb, void* arg)
{
tube->listen_cb = cb;
tube->listen_arg = arg;
if(!comm_base_internal(base))
return 1; /* ignore when no comm base - testing */
return winsock_register_wsaevent(comm_base_internal(base),
&tube->ev_listen, tube->event, &tube_handle_signal, tube);
}
int tube_setup_bg_write(struct tube* ATTR_UNUSED(tube),
struct comm_base* ATTR_UNUSED(base))
{
/* the queue item routine performs the signaling */
return 1;
}
int tube_queue_item(struct tube* tube, uint8_t* msg, size_t len)
{
struct tube_res_list* item =
(struct tube_res_list*)malloc(sizeof(*item));
verbose(VERB_ALGO, "tube queue_item len %d", (int)len);
if(!item) {
free(msg);
log_err("out of memory for async answer");
return 0;
}
item->buf = msg;
item->len = len;
item->next = NULL;
lock_basic_lock(&tube->res_lock);
/* add at back of list, since the first one may be partially written */
if(tube->res_last)
tube->res_last->next = item;
else tube->res_list = item;
tube->res_last = item;
/* signal the eventhandle */
if(!WSASetEvent(tube->event)) {
log_err("WSASetEvent: %s", wsa_strerror(WSAGetLastError()));
}
lock_basic_unlock(&tube->res_lock);
return 1;
}
void tube_handle_signal(int ATTR_UNUSED(fd), short ATTR_UNUSED(events),
void* arg)
{
struct tube* tube = (struct tube*)arg;
uint8_t* buf;
uint32_t len = 0;
verbose(VERB_ALGO, "tube handle_signal");
while(tube_poll(tube)) {
if(tube_read_msg(tube, &buf, &len, 1)) {
fptr_ok(fptr_whitelist_tube_listen(tube->listen_cb));
(*tube->listen_cb)(tube, buf, len, NETEVENT_NOERROR,
tube->listen_arg);
}
}
}
#endif /* USE_WINSOCK */