/
ipv4.c
238 lines (194 loc) · 5.73 KB
/
ipv4.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
/** @file
* @brief IPv4 related functions
*/
/*
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <logging/log.h>
LOG_MODULE_REGISTER(net_ipv4, CONFIG_NET_IPV4_LOG_LEVEL);
#include <errno.h>
#include <net/net_core.h>
#include <net/net_pkt.h>
#include <net/net_stats.h>
#include <net/net_context.h>
#include "net_private.h"
#include "connection.h"
#include "net_stats.h"
#include "icmpv4.h"
#include "udp_internal.h"
#include "tcp_internal.h"
#include "ipv4.h"
/* Timeout for various buffer allocations in this file. */
#define NET_BUF_TIMEOUT K_MSEC(50)
int net_ipv4_create(struct net_pkt *pkt,
const struct in_addr *src,
const struct in_addr *dst)
{
NET_PKT_DATA_ACCESS_CONTIGUOUS_DEFINE(ipv4_access, struct net_ipv4_hdr);
struct net_ipv4_hdr *ipv4_hdr;
ipv4_hdr = (struct net_ipv4_hdr *)net_pkt_get_data(pkt, &ipv4_access);
if (!ipv4_hdr) {
return -ENOBUFS;
}
ipv4_hdr->vhl = 0x45;
ipv4_hdr->tos = 0x00;
ipv4_hdr->len = 0U;
ipv4_hdr->id[0] = 0U;
ipv4_hdr->id[1] = 0U;
ipv4_hdr->offset[0] = 0U;
ipv4_hdr->offset[1] = 0U;
ipv4_hdr->ttl = net_pkt_ipv4_ttl(pkt);
if (ipv4_hdr->ttl == 0U) {
ipv4_hdr->ttl = net_if_ipv4_get_ttl(net_pkt_iface(pkt));
}
ipv4_hdr->proto = 0U;
ipv4_hdr->chksum = 0U;
net_ipaddr_copy(&ipv4_hdr->dst, dst);
net_ipaddr_copy(&ipv4_hdr->src, src);
net_pkt_set_ip_hdr_len(pkt, sizeof(struct net_ipv4_hdr));
return net_pkt_set_data(pkt, &ipv4_access);
}
int net_ipv4_finalize(struct net_pkt *pkt, u8_t next_header_proto)
{
NET_PKT_DATA_ACCESS_CONTIGUOUS_DEFINE(ipv4_access, struct net_ipv4_hdr);
struct net_ipv4_hdr *ipv4_hdr;
net_pkt_set_overwrite(pkt, true);
ipv4_hdr = (struct net_ipv4_hdr *)net_pkt_get_data(pkt, &ipv4_access);
if (!ipv4_hdr) {
return -ENOBUFS;
}
ipv4_hdr->len = htons(net_pkt_get_len(pkt));
ipv4_hdr->proto = next_header_proto;
if (net_if_need_calc_tx_checksum(net_pkt_iface(pkt))) {
ipv4_hdr->chksum = net_calc_chksum_ipv4(pkt);
}
net_pkt_set_data(pkt, &ipv4_access);
if (IS_ENABLED(CONFIG_NET_UDP) &&
next_header_proto == IPPROTO_UDP) {
return net_udp_finalize(pkt);
} else if (IS_ENABLED(CONFIG_NET_TCP) &&
next_header_proto == IPPROTO_TCP) {
return net_tcp_finalize(pkt);
} else if (next_header_proto == IPPROTO_ICMP) {
return net_icmpv4_finalize(pkt);
}
return 0;
}
const struct in_addr *net_ipv4_unspecified_address(void)
{
static const struct in_addr addr;
return &addr;
}
const struct in_addr *net_ipv4_broadcast_address(void)
{
static const struct in_addr addr = { { { 255, 255, 255, 255 } } };
return &addr;
}
enum net_verdict net_ipv4_input(struct net_pkt *pkt)
{
NET_PKT_DATA_ACCESS_CONTIGUOUS_DEFINE(ipv4_access, struct net_ipv4_hdr);
NET_PKT_DATA_ACCESS_DEFINE(udp_access, struct net_udp_hdr);
NET_PKT_DATA_ACCESS_DEFINE(tcp_access, struct net_tcp_hdr);
int real_len = net_pkt_get_len(pkt);
enum net_verdict verdict = NET_DROP;
union net_proto_header proto_hdr;
struct net_ipv4_hdr *hdr;
union net_ip_header ip;
u8_t hdr_len;
int pkt_len;
net_stats_update_ipv4_recv(net_pkt_iface(pkt));
hdr = (struct net_ipv4_hdr *)net_pkt_get_data(pkt, &ipv4_access);
if (!hdr) {
NET_DBG("DROP: no buffer");
goto drop;
}
hdr_len = (hdr->vhl & NET_IPV4_IHL_MASK) * 4U;
if (hdr_len < sizeof(struct net_ipv4_hdr)) {
NET_DBG("DROP: Invalid hdr length");
goto drop;
}
net_pkt_set_ip_hdr_len(pkt, hdr_len);
pkt_len = ntohs(hdr->len);
if (real_len < pkt_len) {
NET_DBG("DROP: pkt len per hdr %d != pkt real len %d",
pkt_len, real_len);
goto drop;
} else if (real_len > pkt_len) {
net_pkt_update_length(pkt, pkt_len);
}
if (net_ipv4_is_addr_mcast(&hdr->src)) {
NET_DBG("DROP: src addr is %s", "mcast");
goto drop;
}
if (net_ipv4_is_addr_bcast(net_pkt_iface(pkt), &hdr->src)) {
NET_DBG("DROP: src addr is %s", "bcast");
goto drop;
}
if (net_ipv4_is_addr_unspecified(&hdr->src)) {
NET_DBG("DROP: src addr is %s", "unspecified");
goto drop;
}
if (net_if_need_calc_rx_checksum(net_pkt_iface(pkt)) &&
net_calc_chksum_ipv4(pkt) != 0U) {
NET_DBG("DROP: invalid chksum");
goto drop;
}
if ((!net_ipv4_is_my_addr(&hdr->dst) &&
!net_ipv4_is_addr_mcast(&hdr->dst) &&
!(hdr->proto == IPPROTO_UDP &&
(net_ipv4_addr_cmp(&hdr->dst, net_ipv4_broadcast_address()) ||
/* RFC 1122 ch. 3.3.6 The 0.0.0.0 is non-standard bcast addr */
(IS_ENABLED(CONFIG_NET_IPV4_ACCEPT_ZERO_BROADCAST) &&
net_ipv4_addr_cmp(&hdr->dst,
net_ipv4_unspecified_address()))))) ||
(hdr->proto == IPPROTO_TCP &&
net_ipv4_is_addr_bcast(net_pkt_iface(pkt), &hdr->dst))) {
NET_DBG("DROP: not for me");
goto drop;
}
net_pkt_acknowledge_data(pkt, &ipv4_access);
if (hdr_len > sizeof(struct net_ipv4_hdr)) {
/* There are probably options, let's skip them */
if (net_pkt_skip(pkt, hdr_len - sizeof(struct net_ipv4_hdr))) {
NET_DBG("Header too big? %u", hdr_len);
goto drop;
}
}
net_pkt_set_ipv4_ttl(pkt, hdr->ttl);
net_pkt_set_family(pkt, PF_INET);
NET_DBG("IPv4 packet received from %s to %s",
log_strdup(net_sprint_ipv4_addr(&hdr->src)),
log_strdup(net_sprint_ipv4_addr(&hdr->dst)));
switch (hdr->proto) {
case IPPROTO_ICMP:
verdict = net_icmpv4_input(pkt, hdr);
break;
case IPPROTO_TCP:
proto_hdr.tcp = net_tcp_input(pkt, &tcp_access);
if (proto_hdr.tcp) {
verdict = NET_OK;
}
break;
case IPPROTO_UDP:
proto_hdr.udp = net_udp_input(pkt, &udp_access);
if (proto_hdr.udp) {
verdict = NET_OK;
}
break;
}
if (verdict == NET_DROP) {
goto drop;
} else if (hdr->proto == IPPROTO_ICMP) {
return verdict;
}
ip.ipv4 = hdr;
verdict = net_conn_input(pkt, &ip, hdr->proto, &proto_hdr);
if (verdict != NET_DROP) {
return verdict;
}
drop:
net_stats_update_ipv4_drop(net_pkt_iface(pkt));
return NET_DROP;
}