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samba-mirror/lib/addns/dnssock.c
Noel Power 849ffbc825 lib/adnss: clang: Fix The left operand of '!=' is a garbage value
Fixes:

lib/addns/dnssock.c:143:3: warning: The left operand of '!=' is a garbage value <--[clang]
                TALLOC_FREE(conn);
                ^
1 warning generated.

Signed-off-by: Noel Power <noel.power@suse.com>
Reviewed-by: Gary Lockyer <gary@catalyst.net.nz>
2019-07-24 21:33:20 +00:00

421 lines
9.4 KiB
C

/*
Linux DNS client library implementation
Copyright (C) 2006 Krishna Ganugapati <krishnag@centeris.com>
Copyright (C) 2006 Gerald Carter <jerry@samba.org>
** NOTE! The following LGPL license applies to the libaddns
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "replace.h"
#include "dns.h"
#include <sys/time.h>
#include <unistd.h>
#include "system/select.h"
#include "../lib/util/debug.h"
static int destroy_dns_connection(struct dns_connection *conn)
{
return close(conn->s);
}
/********************************************************************
********************************************************************/
static DNS_ERROR dns_open_helper(const char *nameserver,
const char *service,
struct addrinfo *hints,
TALLOC_CTX *mem_ctx,
struct dns_connection **ret_conn)
{
int ret;
struct addrinfo *rp;
struct addrinfo *ai_result = NULL;
struct dns_connection *conn = NULL;
if (!(conn = talloc(mem_ctx, struct dns_connection))) {
return ERROR_DNS_NO_MEMORY;
}
ret = getaddrinfo(nameserver, service, hints, &ai_result);
if (ret != 0) {
DEBUG(1,("dns_tcp_open: getaddrinfo: %s\n", gai_strerror(ret)));
TALLOC_FREE(conn);
return ERROR_DNS_INVALID_NAME_SERVER;
}
for (rp = ai_result; rp != NULL; rp = rp->ai_next) {
conn->s = socket(rp->ai_family,
rp->ai_socktype,
rp->ai_protocol);
if (conn->s == -1) {
continue;
}
do {
ret = connect(conn->s, rp->ai_addr, rp->ai_addrlen);
} while ((ret == -1) && (errno == EINTR));
if (ret != -1) {
/* Successful connect */
break;
}
close(conn->s);
}
freeaddrinfo(ai_result);
if (rp == NULL) {
TALLOC_FREE(conn);
return ERROR_DNS_CONNECTION_FAILED;
}
talloc_set_destructor(conn, destroy_dns_connection);
*ret_conn = conn;
return ERROR_DNS_SUCCESS;
}
static DNS_ERROR dns_tcp_open( const char *nameserver,
TALLOC_CTX *mem_ctx,
struct dns_connection **result )
{
struct addrinfo hints;
struct dns_connection *conn;
DNS_ERROR dns_ret;
char service[16];
snprintf(service, sizeof(service), "%d", DNS_TCP_PORT);
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = 0;
hints.ai_protocol = IPPROTO_TCP;
dns_ret = dns_open_helper(nameserver, service, &hints, mem_ctx, &conn);
if (!ERR_DNS_IS_OK(dns_ret)) {
return dns_ret;
}
conn->hType = DNS_TCP;
*result = conn;
return ERROR_DNS_SUCCESS;
}
/********************************************************************
* ********************************************************************/
static DNS_ERROR dns_udp_open( const char *nameserver,
TALLOC_CTX *mem_ctx,
struct dns_connection **result )
{
struct addrinfo hints;
struct sockaddr_storage RecvAddr;
struct dns_connection *conn = NULL;
DNS_ERROR dns_ret;
socklen_t RecvAddrLen;
char service[16];
snprintf(service, sizeof(service), "%d", DNS_UDP_PORT);
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
hints.ai_flags = 0;
hints.ai_protocol = IPPROTO_UDP;
dns_ret = dns_open_helper(nameserver, service, &hints, mem_ctx, &conn);
if (!ERR_DNS_IS_OK(dns_ret)) {
TALLOC_FREE(conn);
return dns_ret;
}
/* Set up the RecvAddr structure with the IP address of
the receiver and the specified port number. */
RecvAddrLen = sizeof(RecvAddr);
if (getpeername(conn->s,
(struct sockaddr *)&RecvAddr,
&RecvAddrLen) == -1) {
return ERROR_DNS_CONNECTION_FAILED;
}
conn->hType = DNS_UDP;
memcpy(&conn->RecvAddr, &RecvAddr, sizeof(struct sockaddr_storage));
*result = conn;
return ERROR_DNS_SUCCESS;
}
/********************************************************************
********************************************************************/
DNS_ERROR dns_open_connection( const char *nameserver, int32_t dwType,
TALLOC_CTX *mem_ctx,
struct dns_connection **conn )
{
switch ( dwType ) {
case DNS_TCP:
return dns_tcp_open( nameserver, mem_ctx, conn );
case DNS_UDP:
return dns_udp_open( nameserver, mem_ctx, conn );
}
return ERROR_DNS_INVALID_PARAMETER;
}
static DNS_ERROR write_all(int fd, uint8_t *data, size_t len)
{
size_t total = 0;
while (total < len) {
ssize_t ret;
do {
ret = write(fd, data + total, len - total);
} while ((ret == -1) && (errno == EINTR));
if (ret <= 0) {
/*
* EOF or error
*/
return ERROR_DNS_SOCKET_ERROR;
}
total += ret;
}
return ERROR_DNS_SUCCESS;
}
static DNS_ERROR dns_send_tcp(struct dns_connection *conn,
const struct dns_buffer *buf)
{
uint16_t len = htons(buf->offset);
DNS_ERROR err;
err = write_all(conn->s, (uint8_t *)&len, sizeof(len));
if (!ERR_DNS_IS_OK(err)) return err;
return write_all(conn->s, buf->data, buf->offset);
}
static DNS_ERROR dns_send_udp(struct dns_connection *conn,
const struct dns_buffer *buf)
{
ssize_t ret;
do {
ret = send(conn->s, buf->data, buf->offset, 0);
} while ((ret == -1) && (errno == EINTR));
if (ret != buf->offset) {
return ERROR_DNS_SOCKET_ERROR;
}
return ERROR_DNS_SUCCESS;
}
DNS_ERROR dns_send(struct dns_connection *conn, const struct dns_buffer *buf)
{
if (conn->hType == DNS_TCP) {
return dns_send_tcp(conn, buf);
}
if (conn->hType == DNS_UDP) {
return dns_send_udp(conn, buf);
}
return ERROR_DNS_INVALID_PARAMETER;
}
static DNS_ERROR read_all(int fd, uint8_t *data, size_t len)
{
size_t total = 0;
while (total < len) {
struct pollfd pfd;
ssize_t ret;
int fd_ready;
ZERO_STRUCT(pfd);
pfd.fd = fd;
pfd.events = POLLIN|POLLHUP;
fd_ready = poll(&pfd, 1, 10000);
if (fd_ready == -1) {
if (errno == EINTR) {
continue;
}
return ERROR_DNS_SOCKET_ERROR;
}
if ( fd_ready == 0 ) {
/* read timeout */
return ERROR_DNS_SOCKET_ERROR;
}
do {
ret = read(fd, data + total, len - total);
} while ((ret == -1) && (errno == EINTR));
if (ret <= 0) {
/* EOF or error */
return ERROR_DNS_SOCKET_ERROR;
}
total += ret;
}
return ERROR_DNS_SUCCESS;
}
static DNS_ERROR dns_receive_tcp(TALLOC_CTX *mem_ctx,
struct dns_connection *conn,
struct dns_buffer **presult)
{
struct dns_buffer *buf;
DNS_ERROR err;
uint16_t len;
if (!(buf = talloc_zero(mem_ctx, struct dns_buffer))) {
return ERROR_DNS_NO_MEMORY;
}
err = read_all(conn->s, (uint8_t *)&len, sizeof(len));
if (!ERR_DNS_IS_OK(err)) {
return err;
}
buf->size = ntohs(len);
if (buf->size == 0) {
*presult = buf;
return ERROR_DNS_SUCCESS;
}
if (!(buf->data = talloc_array(buf, uint8_t, buf->size))) {
TALLOC_FREE(buf);
return ERROR_DNS_NO_MEMORY;
}
err = read_all(conn->s, buf->data, talloc_get_size(buf->data));
if (!ERR_DNS_IS_OK(err)) {
TALLOC_FREE(buf);
return err;
}
*presult = buf;
return ERROR_DNS_SUCCESS;
}
static DNS_ERROR dns_receive_udp(TALLOC_CTX *mem_ctx,
struct dns_connection *conn,
struct dns_buffer **presult)
{
struct dns_buffer *buf;
ssize_t received;
if (!(buf = talloc_zero(mem_ctx, struct dns_buffer))) {
return ERROR_DNS_NO_MEMORY;
}
/*
* UDP based DNS can only be 512 bytes
*/
if (!(buf->data = talloc_array(buf, uint8_t, 512))) {
TALLOC_FREE(buf);
return ERROR_DNS_NO_MEMORY;
}
do {
received = recv(conn->s, (void *)buf->data, 512, 0);
} while ((received == -1) && (errno == EINTR));
if (received == -1) {
TALLOC_FREE(buf);
return ERROR_DNS_SOCKET_ERROR;
}
if (received > 512) {
TALLOC_FREE(buf);
return ERROR_DNS_BAD_RESPONSE;
}
buf->size = received;
buf->offset = 0;
*presult = buf;
return ERROR_DNS_SUCCESS;
}
DNS_ERROR dns_receive(TALLOC_CTX *mem_ctx, struct dns_connection *conn,
struct dns_buffer **presult)
{
if (conn->hType == DNS_TCP) {
return dns_receive_tcp(mem_ctx, conn, presult);
}
if (conn->hType == DNS_UDP) {
return dns_receive_udp(mem_ctx, conn, presult);
}
return ERROR_DNS_INVALID_PARAMETER;
}
DNS_ERROR dns_transaction(TALLOC_CTX *mem_ctx, struct dns_connection *conn,
const struct dns_request *req,
struct dns_request **resp)
{
struct dns_buffer *buf = NULL;
DNS_ERROR err;
err = dns_marshall_request(mem_ctx, req, &buf);
if (!ERR_DNS_IS_OK(err)) goto error;
err = dns_send(conn, buf);
if (!ERR_DNS_IS_OK(err)) goto error;
TALLOC_FREE(buf);
err = dns_receive(mem_ctx, conn, &buf);
if (!ERR_DNS_IS_OK(err)) goto error;
err = dns_unmarshall_request(mem_ctx, buf, resp);
error:
TALLOC_FREE(buf);
return err;
}
DNS_ERROR dns_update_transaction(TALLOC_CTX *mem_ctx,
struct dns_connection *conn,
struct dns_update_request *up_req,
struct dns_update_request **up_resp)
{
struct dns_request *resp;
DNS_ERROR err;
err = dns_transaction(mem_ctx, conn, dns_update2request(up_req),
&resp);
if (!ERR_DNS_IS_OK(err)) return err;
*up_resp = dns_request2update(resp);
return ERROR_DNS_SUCCESS;
}