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/*
* util/proxy_protocol.c - event notification
*
* Copyright (c) 2022, 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 PROXY protocol functions.
*/
#include "util/proxy_protocol.h"
/**
* Internal struct initialized with function pointers for writing uint16 and
* uint32.
*/
struct proxy_protocol_data {
void (*write_uint16)(void* buf, uint16_t data);
void (*write_uint32)(void* buf, uint32_t data);
};
struct proxy_protocol_data pp_data;
/**
* Internal lookup table; could be further generic like sldns_lookup_table
* for all the future generic stuff.
*/
struct proxy_protocol_lookup_table {
int id;
const char *text;
};
/**
* Internal parsing error text; could be exposed with pp_lookup_error.
*/
static struct proxy_protocol_lookup_table pp_parse_errors_data[] = {
{ PP_PARSE_NOERROR, "no parse error" },
{ PP_PARSE_SIZE, "not enough space for header" },
{ PP_PARSE_WRONG_HEADERv2, "could not match PROXYv2 header" },
{ PP_PARSE_UNKNOWN_CMD, "unknown command" },
{ PP_PARSE_UNKNOWN_FAM_PROT, "unknown family and protocol" },
};
void
pp_init(void (*write_uint16)(void* buf, uint16_t data),
void (*write_uint32)(void* buf, uint32_t data)) {
pp_data.write_uint16 = write_uint16;
pp_data.write_uint32 = write_uint32;
}
const char*
pp_lookup_error(enum pp_parse_errors error) {
return pp_parse_errors_data[error].text;
}
size_t
pp2_write_to_buf(uint8_t* buf, size_t buflen,
#ifdef INET6
struct sockaddr_storage* src,
#else
struct sockaddr_in* src,
#endif
int stream)
{
int af;
size_t expected_size;
if(!src) return 0;
af = (int)((struct sockaddr_in*)src)->sin_family;
expected_size = PP2_HEADER_SIZE + (af==AF_INET?12:36);
if(buflen < expected_size) {
return 0;
}
/* sig */
memcpy(buf, PP2_SIG, PP2_SIG_LEN);
buf += PP2_SIG_LEN;
/* version and command */
*buf = (PP2_VERSION << 4) | PP2_CMD_PROXY;
buf++;
switch(af) {
case AF_INET:
/* family and protocol */
*buf = (PP2_AF_INET<<4) |
(stream?PP2_PROT_STREAM:PP2_PROT_DGRAM);
buf++;
/* length */
(*pp_data.write_uint16)(buf, 12);
buf += 2;
/* src addr */
memcpy(buf,
&((struct sockaddr_in*)src)->sin_addr.s_addr, 4);
buf += 4;
/* dst addr */
(*pp_data.write_uint32)(buf, 0);
buf += 4;
/* src port */
memcpy(buf,
&((struct sockaddr_in*)src)->sin_port, 2);
buf += 2;
/* dst addr */
/* dst port */
(*pp_data.write_uint16)(buf, 12);
break;
#ifdef INET6
case AF_INET6:
/* family and protocol */
*buf = (PP2_AF_INET6<<4) |
(stream?PP2_PROT_STREAM:PP2_PROT_DGRAM);
buf++;
/* length */
(*pp_data.write_uint16)(buf, 36);
buf += 2;
/* src addr */
memcpy(buf,
&((struct sockaddr_in6*)src)->sin6_addr, 16);
buf += 16;
/* dst addr */
memset(buf, 0, 16);
buf += 16;
/* src port */
memcpy(buf, &((struct sockaddr_in6*)src)->sin6_port, 2);
buf += 2;
/* dst port */
(*pp_data.write_uint16)(buf, 0);
break;
#endif /* INET6 */
case AF_UNIX:
/* fallthrough */
default:
return 0;
}
return expected_size;
}
int
pp2_read_header(uint8_t* buf, size_t buflen)
{
size_t size;
struct pp2_header* header = (struct pp2_header*)buf;
/* Try to fail all the unsupported cases first. */
if(buflen < PP2_HEADER_SIZE) {
return PP_PARSE_SIZE;
}
/* Check for PROXYv2 header */
if(memcmp(header, PP2_SIG, PP2_SIG_LEN) != 0 ||
((header->ver_cmd & 0xF0)>>4) != PP2_VERSION) {
return PP_PARSE_WRONG_HEADERv2;
}
/* Check the length */
size = PP2_HEADER_SIZE + ntohs(header->len);
if(buflen < size) {
return PP_PARSE_SIZE;
}
/* Check for supported commands */
if((header->ver_cmd & 0xF) != PP2_CMD_LOCAL &&
(header->ver_cmd & 0xF) != PP2_CMD_PROXY) {
return PP_PARSE_UNKNOWN_CMD;
}
/* Check for supported family and protocol */
if(header->fam_prot != PP2_UNSPEC_UNSPEC &&
header->fam_prot != PP2_INET_STREAM &&
header->fam_prot != PP2_INET_DGRAM &&
header->fam_prot != PP2_INET6_STREAM &&
header->fam_prot != PP2_INET6_DGRAM &&
header->fam_prot != PP2_UNIX_STREAM &&
header->fam_prot != PP2_UNIX_DGRAM) {
return PP_PARSE_UNKNOWN_FAM_PROT;
}
/* We have a correct header */
return PP_PARSE_NOERROR;
}
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