1 /*
2 * util/proxy_protocol.c - event notification
3 *
4 * Copyright (c) 2022, NLnet Labs. All rights reserved.
5 *
6 * This software is open source.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 *
15 * Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
18 *
19 * Neither the name of the NLNET LABS nor the names of its contributors may
20 * be used to endorse or promote products derived from this software without
21 * specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 /**
37 * \file
38 *
39 * This file contains PROXY protocol functions.
40 */
41 #include "util/proxy_protocol.h"
42
43 /**
44 * Internal struct initialized with function pointers for writing uint16 and
45 * uint32.
46 */
47 struct proxy_protocol_data {
48 void (*write_uint16)(void* buf, uint16_t data);
49 void (*write_uint32)(void* buf, uint32_t data);
50 };
51 struct proxy_protocol_data pp_data;
52
53 /**
54 * Internal lookup table; could be further generic like sldns_lookup_table
55 * for all the future generic stuff.
56 */
57 struct proxy_protocol_lookup_table {
58 int id;
59 const char *text;
60 };
61
62 /**
63 * Internal parsing error text; could be exposed with pp_lookup_error.
64 */
65 static struct proxy_protocol_lookup_table pp_parse_errors_data[] = {
66 { PP_PARSE_NOERROR, "no parse error" },
67 { PP_PARSE_SIZE, "not enough space for header" },
68 { PP_PARSE_WRONG_HEADERv2, "could not match PROXYv2 header" },
69 { PP_PARSE_UNKNOWN_CMD, "unknown command" },
70 { PP_PARSE_UNKNOWN_FAM_PROT, "unknown family and protocol" },
71 };
72
73 void
pp_init(void (* write_uint16)(void * buf,uint16_t data),void (* write_uint32)(void * buf,uint32_t data))74 pp_init(void (*write_uint16)(void* buf, uint16_t data),
75 void (*write_uint32)(void* buf, uint32_t data)) {
76 pp_data.write_uint16 = write_uint16;
77 pp_data.write_uint32 = write_uint32;
78 }
79
80 const char*
pp_lookup_error(enum pp_parse_errors error)81 pp_lookup_error(enum pp_parse_errors error) {
82 return pp_parse_errors_data[error].text;
83 }
84
85 size_t
pp2_write_to_buf(uint8_t * buf,size_t buflen,struct sockaddr_storage * src,int stream)86 pp2_write_to_buf(uint8_t* buf, size_t buflen,
87 #ifdef INET6
88 struct sockaddr_storage* src,
89 #else
90 struct sockaddr_in* src,
91 #endif
92 int stream)
93 {
94 int af;
95 size_t expected_size;
96 if(!src) return 0;
97 af = (int)((struct sockaddr_in*)src)->sin_family;
98 expected_size = PP2_HEADER_SIZE + (af==AF_INET?12:36);
99 if(buflen < expected_size) {
100 return 0;
101 }
102 /* sig */
103 memcpy(buf, PP2_SIG, PP2_SIG_LEN);
104 buf += PP2_SIG_LEN;
105 /* version and command */
106 *buf = (PP2_VERSION << 4) | PP2_CMD_PROXY;
107 buf++;
108 switch(af) {
109 case AF_INET:
110 /* family and protocol */
111 *buf = (PP2_AF_INET<<4) |
112 (stream?PP2_PROT_STREAM:PP2_PROT_DGRAM);
113 buf++;
114 /* length */
115 (*pp_data.write_uint16)(buf, 12);
116 buf += 2;
117 /* src addr */
118 memcpy(buf,
119 &((struct sockaddr_in*)src)->sin_addr.s_addr, 4);
120 buf += 4;
121 /* dst addr */
122 (*pp_data.write_uint32)(buf, 0);
123 buf += 4;
124 /* src port */
125 memcpy(buf,
126 &((struct sockaddr_in*)src)->sin_port, 2);
127 buf += 2;
128 /* dst addr */
129 /* dst port */
130 (*pp_data.write_uint16)(buf, 12);
131 break;
132 #ifdef INET6
133 case AF_INET6:
134 /* family and protocol */
135 *buf = (PP2_AF_INET6<<4) |
136 (stream?PP2_PROT_STREAM:PP2_PROT_DGRAM);
137 buf++;
138 /* length */
139 (*pp_data.write_uint16)(buf, 36);
140 buf += 2;
141 /* src addr */
142 memcpy(buf,
143 &((struct sockaddr_in6*)src)->sin6_addr, 16);
144 buf += 16;
145 /* dst addr */
146 memset(buf, 0, 16);
147 buf += 16;
148 /* src port */
149 memcpy(buf, &((struct sockaddr_in6*)src)->sin6_port, 2);
150 buf += 2;
151 /* dst port */
152 (*pp_data.write_uint16)(buf, 0);
153 break;
154 #endif /* INET6 */
155 case AF_UNIX:
156 ATTR_FALLTHROUGH
157 /* fallthrough */
158 default:
159 return 0;
160 }
161 return expected_size;
162 }
163
164 int
pp2_read_header(uint8_t * buf,size_t buflen)165 pp2_read_header(uint8_t* buf, size_t buflen)
166 {
167 size_t size;
168 struct pp2_header* header = (struct pp2_header*)buf;
169 /* Try to fail all the unsupported cases first. */
170 if(buflen < PP2_HEADER_SIZE) {
171 return PP_PARSE_SIZE;
172 }
173 /* Check for PROXYv2 header */
174 if(memcmp(header, PP2_SIG, PP2_SIG_LEN) != 0 ||
175 ((header->ver_cmd & 0xF0)>>4) != PP2_VERSION) {
176 return PP_PARSE_WRONG_HEADERv2;
177 }
178 /* Check the length */
179 size = PP2_HEADER_SIZE + ntohs(header->len);
180 if(buflen < size) {
181 return PP_PARSE_SIZE;
182 }
183 /* Check for supported commands */
184 if((header->ver_cmd & 0xF) != PP2_CMD_LOCAL &&
185 (header->ver_cmd & 0xF) != PP2_CMD_PROXY) {
186 return PP_PARSE_UNKNOWN_CMD;
187 }
188 /* Check for supported family and protocol */
189 if(header->fam_prot != PP2_UNSPEC_UNSPEC &&
190 header->fam_prot != PP2_INET_STREAM &&
191 header->fam_prot != PP2_INET_DGRAM &&
192 header->fam_prot != PP2_INET6_STREAM &&
193 header->fam_prot != PP2_INET6_DGRAM &&
194 header->fam_prot != PP2_UNIX_STREAM &&
195 header->fam_prot != PP2_UNIX_DGRAM) {
196 return PP_PARSE_UNKNOWN_FAM_PROT;
197 }
198 /* We have a correct header */
199 return PP_PARSE_NOERROR;
200 }
201