/*
Unix SMB/CIFS implementation.
async socket syscalls
Copyright (C) Volker Lendecke 2008
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
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.
You should have received a copy of the GNU General Public License
along with this program. If not, see .
*/
#include "includes.h"
#include "lib/talloc/talloc.h"
#include "lib/tevent/tevent.h"
#include "lib/async_req/async_req.h"
#include "lib/async_req/async_sock.h"
#include "lib/util/tevent_unix.h"
#include
#ifndef TALLOC_FREE
#define TALLOC_FREE(ctx) do { talloc_free(ctx); ctx=NULL; } while(0)
#endif
/**
* Discriminator for async_syscall_state
*/
enum async_syscall_type {
ASYNC_SYSCALL_SEND,
ASYNC_SYSCALL_RECV,
};
/**
* Holder for syscall arguments and the result
*/
struct async_syscall_state {
enum async_syscall_type syscall_type;
struct tevent_fd *fde;
union {
struct param_send {
int fd;
const void *buffer;
size_t length;
int flags;
} param_send;
struct param_recv {
int fd;
void *buffer;
size_t length;
int flags;
} param_recv;
} param;
union {
ssize_t result_ssize_t;
size_t result_size_t;
int result_int;
} result;
int sys_errno;
};
/**
* @brief Map async_req states to unix-style errnos
* @param[in] req The async req to get the state from
* @param[out] err Pointer to take the unix-style errno
*
* @return true if the async_req is in an error state, false otherwise
*/
bool async_req_is_errno(struct async_req *req, int *err)
{
enum async_req_state state;
uint64_t error;
if (!async_req_is_error(req, &state, &error)) {
return false;
}
switch (state) {
case ASYNC_REQ_USER_ERROR:
*err = (int)error;
break;
case ASYNC_REQ_TIMED_OUT:
#ifdef ETIMEDOUT
*err = ETIMEDOUT;
#else
*err = EAGAIN;
#endif
break;
case ASYNC_REQ_NO_MEMORY:
*err = ENOMEM;
break;
default:
*err = EIO;
break;
}
return true;
}
int async_req_simple_recv_errno(struct async_req *req)
{
int err;
if (async_req_is_errno(req, &err)) {
return err;
}
return 0;
}
/**
* @brief Create a new async syscall req
* @param[in] mem_ctx The memory context to hang the result off
* @param[in] ev The event context to work from
* @param[in] type Which syscall will this be
* @param[in] pstate Where to put the newly created private_data state
* @retval The new request
*
* This is a helper function to prepare a new struct async_req with an
* associated struct async_syscall_state. The async_syscall_state will be put
* into the async_req as private_data.
*/
static struct async_req *async_syscall_new(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
enum async_syscall_type type,
struct async_syscall_state **pstate)
{
struct async_req *result;
struct async_syscall_state *state;
if (!async_req_setup(mem_ctx, &result, &state,
struct async_syscall_state)) {
return NULL;
}
state->syscall_type = type;
result->private_data = state;
*pstate = state;
return result;
}
/**
* @brief Create a new async syscall req based on a fd
* @param[in] mem_ctx The memory context to hang the result off
* @param[in] ev The event context to work from
* @param[in] type Which syscall will this be
* @param[in] fd The file descriptor we work on
* @param[in] fde_flags TEVENT_FD_READ/WRITE -- what are we interested in?
* @param[in] fde_cb The callback function for the file descriptor event
* @param[in] pstate Where to put the newly created private_data state
* @retval The new request
*
* This is a helper function to prepare a new struct async_req with an
* associated struct async_syscall_state and an associated file descriptor
* event.
*/
static struct async_req *async_fde_syscall_new(
TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
enum async_syscall_type type,
int fd,
uint16_t fde_flags,
void (*fde_cb)(struct tevent_context *ev,
struct tevent_fd *fde, uint16_t flags,
void *priv),
struct async_syscall_state **pstate)
{
struct async_req *result;
struct async_syscall_state *state;
result = async_syscall_new(mem_ctx, ev, type, &state);
if (result == NULL) {
return NULL;
}
state->fde = tevent_add_fd(ev, state, fd, fde_flags, fde_cb, result);
if (state->fde == NULL) {
TALLOC_FREE(result);
return NULL;
}
*pstate = state;
return result;
}
/**
* Retrieve a ssize_t typed result from an async syscall
* @param[in] req The syscall that has just finished
* @param[out] perrno Where to put the syscall's errno
* @retval The return value from the asynchronously called syscall
*/
ssize_t async_syscall_result_ssize_t(struct async_req *req, int *perrno)
{
struct async_syscall_state *state = talloc_get_type_abort(
req->private_data, struct async_syscall_state);
*perrno = state->sys_errno;
return state->result.result_ssize_t;
}
/**
* Retrieve a size_t typed result from an async syscall
* @param[in] req The syscall that has just finished
* @param[out] perrno Where to put the syscall's errno
* @retval The return value from the asynchronously called syscall
*/
size_t async_syscall_result_size_t(struct async_req *req, int *perrno)
{
struct async_syscall_state *state = talloc_get_type_abort(
req->private_data, struct async_syscall_state);
*perrno = state->sys_errno;
return state->result.result_size_t;
}
/**
* Retrieve a int typed result from an async syscall
* @param[in] req The syscall that has just finished
* @param[out] perrno Where to put the syscall's errno
* @retval The return value from the asynchronously called syscall
*/
int async_syscall_result_int(struct async_req *req, int *perrno)
{
struct async_syscall_state *state = talloc_get_type_abort(
req->private_data, struct async_syscall_state);
*perrno = state->sys_errno;
return state->result.result_int;
}
/**
* fde event handler for the "send" syscall
* @param[in] ev The event context that sent us here
* @param[in] fde The file descriptor event associated with the send
* @param[in] flags Can only be TEVENT_FD_WRITE here
* @param[in] priv private data, "struct async_req *" in this case
*/
static void async_send_callback(struct tevent_context *ev,
struct tevent_fd *fde, uint16_t flags,
void *priv)
{
struct async_req *req = talloc_get_type_abort(
priv, struct async_req);
struct async_syscall_state *state = talloc_get_type_abort(
req->private_data, struct async_syscall_state);
struct param_send *p = &state->param.param_send;
if (state->syscall_type != ASYNC_SYSCALL_SEND) {
async_req_error(req, EIO);
return;
}
state->result.result_ssize_t = send(p->fd, p->buffer, p->length,
p->flags);
state->sys_errno = errno;
TALLOC_FREE(state->fde);
async_req_done(req);
}
/**
* Async version of send(2)
* @param[in] mem_ctx The memory context to hang the result off
* @param[in] ev The event context to work from
* @param[in] fd The socket to send to
* @param[in] buffer The buffer to send
* @param[in] length How many bytes to send
* @param[in] flags flags passed to send(2)
*
* This function is a direct counterpart of send(2)
*/
struct async_req *async_send(TALLOC_CTX *mem_ctx, struct tevent_context *ev,
int fd, const void *buffer, size_t length,
int flags)
{
struct async_req *result;
struct async_syscall_state *state;
result = async_fde_syscall_new(
mem_ctx, ev, ASYNC_SYSCALL_SEND,
fd, TEVENT_FD_WRITE, async_send_callback,
&state);
if (result == NULL) {
return NULL;
}
state->param.param_send.fd = fd;
state->param.param_send.buffer = buffer;
state->param.param_send.length = length;
state->param.param_send.flags = flags;
return result;
}
/**
* fde event handler for the "recv" syscall
* @param[in] ev The event context that sent us here
* @param[in] fde The file descriptor event associated with the recv
* @param[in] flags Can only be TEVENT_FD_READ here
* @param[in] priv private data, "struct async_req *" in this case
*/
static void async_recv_callback(struct tevent_context *ev,
struct tevent_fd *fde, uint16_t flags,
void *priv)
{
struct async_req *req = talloc_get_type_abort(
priv, struct async_req);
struct async_syscall_state *state = talloc_get_type_abort(
req->private_data, struct async_syscall_state);
struct param_recv *p = &state->param.param_recv;
if (state->syscall_type != ASYNC_SYSCALL_RECV) {
async_req_error(req, EIO);
return;
}
state->result.result_ssize_t = recv(p->fd, p->buffer, p->length,
p->flags);
state->sys_errno = errno;
TALLOC_FREE(state->fde);
async_req_done(req);
}
/**
* Async version of recv(2)
* @param[in] mem_ctx The memory context to hang the result off
* @param[in] ev The event context to work from
* @param[in] fd The socket to recv from
* @param[in] buffer The buffer to recv into
* @param[in] length How many bytes to recv
* @param[in] flags flags passed to recv(2)
*
* This function is a direct counterpart of recv(2)
*/
struct async_req *async_recv(TALLOC_CTX *mem_ctx, struct tevent_context *ev,
int fd, void *buffer, size_t length,
int flags)
{
struct async_req *result;
struct async_syscall_state *state;
result = async_fde_syscall_new(
mem_ctx, ev, ASYNC_SYSCALL_RECV,
fd, TEVENT_FD_READ, async_recv_callback,
&state);
if (result == NULL) {
return NULL;
}
state->param.param_recv.fd = fd;
state->param.param_recv.buffer = buffer;
state->param.param_recv.length = length;
state->param.param_recv.flags = flags;
return result;
}
struct async_connect_state {
int fd;
int result;
int sys_errno;
long old_sockflags;
};
static void async_connect_connected(struct tevent_context *ev,
struct tevent_fd *fde, uint16_t flags,
void *priv);
/**
* @brief async version of connect(2)
* @param[in] mem_ctx The memory context to hang the result off
* @param[in] ev The event context to work from
* @param[in] fd The socket to recv from
* @param[in] address Where to connect?
* @param[in] address_len Length of *address
* @retval The async request
*
* This function sets the socket into non-blocking state to be able to call
* connect in an async state. This will be reset when the request is finished.
*/
struct tevent_req *async_connect_send(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
int fd, const struct sockaddr *address,
socklen_t address_len)
{
struct tevent_req *result;
struct async_connect_state *state;
struct tevent_fd *fde;
result = tevent_req_create(
mem_ctx, &state, struct async_connect_state);
if (result == NULL) {
return NULL;
}
/**
* We have to set the socket to nonblocking for async connect(2). Keep
* the old sockflags around.
*/
state->fd = fd;
state->sys_errno = 0;
state->old_sockflags = fcntl(fd, F_GETFL, 0);
if (state->old_sockflags == -1) {
goto post_errno;
}
set_blocking(fd, false);
state->result = connect(fd, address, address_len);
if (state->result == 0) {
errno = 0;
goto post_errno;
}
/**
* A number of error messages show that something good is progressing
* and that we have to wait for readability.
*
* If none of them are present, bail out.
*/
if (!(errno == EINPROGRESS || errno == EALREADY ||
#ifdef EISCONN
errno == EISCONN ||
#endif
errno == EAGAIN || errno == EINTR)) {
goto post_errno;
}
fde = tevent_add_fd(ev, state, fd, TEVENT_FD_READ | TEVENT_FD_WRITE,
async_connect_connected, result);
if (fde == NULL) {
errno = ENOMEM;
goto post_errno;
}
return result;
post_errno:
state->sys_errno = errno;
fcntl(fd, F_SETFL, state->old_sockflags);
if (state->sys_errno == 0) {
tevent_req_done(result);
} else {
tevent_req_error(result, state->sys_errno);
}
return tevent_req_post(result, ev);
}
/**
* fde event handler for connect(2)
* @param[in] ev The event context that sent us here
* @param[in] fde The file descriptor event associated with the connect
* @param[in] flags Indicate read/writeability of the socket
* @param[in] priv private data, "struct async_req *" in this case
*/
static void async_connect_connected(struct tevent_context *ev,
struct tevent_fd *fde, uint16_t flags,
void *priv)
{
struct tevent_req *req = talloc_get_type_abort(
priv, struct tevent_req);
struct async_connect_state *state = talloc_get_type_abort(
req->private_state, struct async_connect_state);
TALLOC_FREE(fde);
/*
* Stevens, Network Programming says that if there's a
* successful connect, the socket is only writable. Upon an
* error, it's both readable and writable.
*/
if ((flags & (TEVENT_FD_READ|TEVENT_FD_WRITE))
== (TEVENT_FD_READ|TEVENT_FD_WRITE)) {
int sockerr;
socklen_t err_len = sizeof(sockerr);
if (getsockopt(state->fd, SOL_SOCKET, SO_ERROR,
(void *)&sockerr, &err_len) == 0) {
errno = sockerr;
}
state->sys_errno = errno;
DEBUG(10, ("connect returned %s\n", strerror(errno)));
fcntl(state->fd, F_SETFL, state->old_sockflags);
tevent_req_error(req, state->sys_errno);
return;
}
state->sys_errno = 0;
tevent_req_done(req);
}
int async_connect_recv(struct tevent_req *req, int *perrno)
{
struct async_connect_state *state = talloc_get_type_abort(
req->private_state, struct async_connect_state);
int err;
fcntl(state->fd, F_SETFL, state->old_sockflags);
if (tevent_req_is_unix_error(req, &err)) {
*perrno = err;
return -1;
}
if (state->sys_errno == 0) {
return 0;
}
*perrno = state->sys_errno;
return -1;
}
struct writev_state {
struct tevent_context *ev;
int fd;
struct iovec *iov;
int count;
size_t total_size;
};
static void writev_handler(struct tevent_context *ev, struct tevent_fd *fde,
uint16_t flags, void *private_data);
struct tevent_req *writev_send(TALLOC_CTX *mem_ctx, struct tevent_context *ev,
int fd, struct iovec *iov, int count)
{
struct tevent_req *result;
struct writev_state *state;
struct tevent_fd *fde;
result = tevent_req_create(mem_ctx, &state, struct writev_state);
if (result == NULL) {
return NULL;
}
state->ev = ev;
state->fd = fd;
state->total_size = 0;
state->count = count;
state->iov = (struct iovec *)talloc_memdup(
state, iov, sizeof(struct iovec) * count);
if (state->iov == NULL) {
goto fail;
}
fde = tevent_add_fd(ev, state, fd, TEVENT_FD_WRITE, writev_handler,
result);
if (fde == NULL) {
goto fail;
}
return result;
fail:
TALLOC_FREE(result);
return NULL;
}
static void writev_handler(struct tevent_context *ev, struct tevent_fd *fde,
uint16_t flags, void *private_data)
{
struct tevent_req *req = talloc_get_type_abort(
private_data, struct tevent_req);
struct writev_state *state = talloc_get_type_abort(
req->private_state, struct writev_state);
size_t to_write, written;
int i;
to_write = 0;
for (i=0; icount; i++) {
to_write += state->iov[i].iov_len;
}
written = sys_writev(state->fd, state->iov, state->count);
if (written == -1) {
tevent_req_error(req, errno);
return;
}
if (written == 0) {
tevent_req_error(req, EPIPE);
return;
}
state->total_size += written;
if (written == to_write) {
tevent_req_done(req);
return;
}
/*
* We've written less than we were asked to, drop stuff from
* state->iov.
*/
while (written > 0) {
if (written < state->iov[0].iov_len) {
state->iov[0].iov_base =
(char *)state->iov[0].iov_base + written;
state->iov[0].iov_len -= written;
break;
}
written = state->iov[0].iov_len;
state->iov += 1;
state->count -= 1;
}
}
ssize_t writev_recv(struct tevent_req *req, int *perrno)
{
struct writev_state *state = talloc_get_type_abort(
req->private_state, struct writev_state);
if (tevent_req_is_unix_error(req, perrno)) {
return -1;
}
return state->total_size;
}
struct read_packet_state {
int fd;
uint8_t *buf;
size_t nread;
ssize_t (*more)(uint8_t *buf, size_t buflen, void *private_data);
void *private_data;
};
static void read_packet_handler(struct tevent_context *ev,
struct tevent_fd *fde,
uint16_t flags, void *private_data);
struct tevent_req *read_packet_send(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
int fd, size_t initial,
ssize_t (*more)(uint8_t *buf,
size_t buflen,
void *private_data),
void *private_data)
{
struct tevent_req *result;
struct read_packet_state *state;
struct tevent_fd *fde;
result = tevent_req_create(mem_ctx, &state, struct read_packet_state);
if (result == NULL) {
return NULL;
}
state->fd = fd;
state->nread = 0;
state->more = more;
state->private_data = private_data;
state->buf = talloc_array(state, uint8_t, initial);
if (state->buf == NULL) {
goto fail;
}
fde = tevent_add_fd(ev, state, fd, TEVENT_FD_READ, read_packet_handler,
result);
if (fde == NULL) {
goto fail;
}
return result;
fail:
TALLOC_FREE(result);
return NULL;
}
static void read_packet_handler(struct tevent_context *ev,
struct tevent_fd *fde,
uint16_t flags, void *private_data)
{
struct tevent_req *req = talloc_get_type_abort(
private_data, struct tevent_req);
struct read_packet_state *state = talloc_get_type_abort(
req->private_state, struct read_packet_state);
size_t total = talloc_get_size(state->buf);
ssize_t nread, more;
uint8_t *tmp;
nread = read(state->fd, state->buf+state->nread, total-state->nread);
if (nread == -1) {
tevent_req_error(req, errno);
return;
}
if (nread == 0) {
tevent_req_error(req, EPIPE);
return;
}
state->nread += nread;
if (state->nread < total) {
/* Come back later */
return;
}
/*
* We got what was initially requested. See if "more" asks for -- more.
*/
if (state->more == NULL) {
/* Nobody to ask, this is a async read_data */
tevent_req_done(req);
return;
}
more = state->more(state->buf, total, state->private_data);
if (more == -1) {
/* We got an invalid packet, tell the caller */
tevent_req_error(req, EIO);
return;
}
if (more == 0) {
/* We're done, full packet received */
tevent_req_done(req);
return;
}
tmp = TALLOC_REALLOC_ARRAY(state, state->buf, uint8_t, total+more);
if (tevent_req_nomem(tmp, req)) {
return;
}
state->buf = tmp;
}
ssize_t read_packet_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
uint8_t **pbuf, int *perrno)
{
struct read_packet_state *state = talloc_get_type_abort(
req->private_state, struct read_packet_state);
if (tevent_req_is_unix_error(req, perrno)) {
return -1;
}
*pbuf = talloc_move(mem_ctx, &state->buf);
return talloc_get_size(*pbuf);
}