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/*
SSSD
NSS Responder, command parser
Copyright (C) Simo Sorce <ssorce@redhat.com> 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 <http://www.gnu.org/licenses/>.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <string.h>
#include <errno.h>
#include "../talloc/talloc.h"
#include "util/util.h"
#include "nss/nsssrv.h"
#define NSSSRV_PACKET_MEM_SIZE 512
struct nss_packet {
size_t memsize;
uint8_t *buffer;
/* header */
uint32_t *len;
uint32_t *cmd;
uint32_t *status;
uint32_t *reserved;
uint8_t *body;
/* io pointer */
size_t iop;
};
/*
* Allocate a new packet structure
*
* - if size is defined use it otherwise the default packet will be
* NSSSRV_PACKET_MEM_SIZE bytes.
*/
int nss_packet_new(TALLOC_CTX *mem_ctx, size_t size,
enum sss_nss_command cmd,
struct nss_packet **rpacket)
{
struct nss_packet *packet;
packet = talloc(mem_ctx, struct nss_packet);
if (!packet) return ENOMEM;
if (size) {
int n = (size + SSS_NSS_HEADER_SIZE) % NSSSRV_PACKET_MEM_SIZE;
packet->memsize = (n + 1) * NSSSRV_PACKET_MEM_SIZE;
} else {
packet->memsize = NSSSRV_PACKET_MEM_SIZE;
}
packet->buffer = talloc_size(packet, packet->memsize);
if (!packet->buffer) {
talloc_free(packet);
return ENOMEM;
}
memset(packet->buffer, 0, SSS_NSS_HEADER_SIZE);
packet->len = &((uint32_t *)packet->buffer)[0];
packet->cmd = &((uint32_t *)packet->buffer)[1];
packet->status = &((uint32_t *)packet->buffer)[2];
packet->reserved = &((uint32_t *)packet->buffer)[3];
packet->body = (uint8_t *)&((uint32_t *)packet->buffer)[4];
*(packet->len) = size + SSS_NSS_HEADER_SIZE;
*(packet->cmd) = cmd;
packet->iop = 0;
*rpacket = packet;
return EOK;
}
/* grows a packet size only in NSSSRV_PACKET_MEM_SIZE chunks */
int nss_packet_grow(struct nss_packet *packet, size_t size)
{
size_t totlen, len;
uint8_t *newmem;
if (size == 0) {
return EOK;
}
totlen = packet->memsize;
len = *packet->len + size;
/* make sure we do not overflow */
if (totlen < len) {
int n = len % NSSSRV_PACKET_MEM_SIZE + 1;
totlen += n * NSSSRV_PACKET_MEM_SIZE;
if (totlen < len) {
return EINVAL;
}
}
if (totlen > packet->memsize) {
newmem = talloc_realloc_size(packet, packet->buffer, totlen);
if (!newmem) {
return ENOMEM;
}
packet->memsize = totlen;
packet->buffer = newmem;
packet->len = &((uint32_t *)packet->buffer)[0];
packet->cmd = &((uint32_t *)packet->buffer)[1];
packet->status = &((uint32_t *)packet->buffer)[2];
packet->reserved = &((uint32_t *)packet->buffer)[3];
packet->body = (uint8_t *)&((uint32_t *)packet->buffer)[4];
}
*(packet->len) += size;
return 0;
}
int nss_packet_recv(struct nss_packet *packet, int fd)
{
size_t rb;
size_t len;
void *buf;
buf = packet->buffer + packet->iop;
if (packet->iop > 4) len = *packet->len - packet->iop;
else len = packet->memsize - packet->iop;
/* check for wrapping */
if (len > packet->memsize) {
return EINVAL;
}
errno = 0;
rb = recv(fd, buf, len, 0);
if (rb == -1 && errno == EAGAIN) {
return EAGAIN;
}
if (rb == 0) {
return EIO;
}
if (*packet->len > packet->memsize) {
return EINVAL;
}
packet->iop += rb;
if (packet->iop < 4) {
return EAGAIN;
}
if (packet->iop < *packet->len) {
return EAGAIN;
}
return EOK;
}
int nss_packet_send(struct nss_packet *packet, int fd)
{
size_t rb;
size_t len;
void *buf;
buf = packet->buffer + packet->iop;
len = *packet->len - packet->iop;
errno = 0;
rb = send(fd, buf, len, 0);
if (rb == -1 && errno == EAGAIN) {
return EAGAIN;
}
if (rb == 0) {
return EIO;
}
packet->iop += rb;
if (packet->iop < *packet->len) {
return EAGAIN;
}
return EOK;
}
enum sss_nss_command nss_packet_get_cmd(struct nss_packet *packet)
{
return (enum sss_nss_command)(*packet->cmd);
}
void nss_packet_get_body(struct nss_packet *packet, uint8_t **body, size_t *blen)
{
*body = packet->body;
*blen = *packet->len - SSS_NSS_HEADER_SIZE;
}
void nss_packet_set_error(struct nss_packet *packet, int error)
{
*(packet->status) = error;
}
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