Line data Source code
1 : /*
2 : * Copyright (c) 2016 Cisco and/or its affiliates.
3 : * Licensed under the Apache License, Version 2.0 (the "License");
4 : * you may not use this file except in compliance with the License.
5 : * You may obtain a copy of the License at:
6 : *
7 : * http://www.apache.org/licenses/LICENSE-2.0
8 : *
9 : * Unless required by applicable law or agreed to in writing, software
10 : * distributed under the License is distributed on an "AS IS" BASIS,
11 : * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 : * See the License for the specific language governing permissions and
13 : * limitations under the License.
14 : */
15 :
16 : #include <lisp/lisp-cp/packets.h>
17 : #include <lisp/lisp-cp/lisp_cp_messages.h>
18 : #include <vnet/udp/udp_packet.h>
19 : #include <vnet/ip/ip4_inlines.h>
20 : #include <vnet/ip/ip6_inlines.h>
21 :
22 : /* Returns IP ID for the packet */
23 : /* static u16 ip_id = 0;
24 : static inline u16
25 : get_IP_ID()
26 : {
27 : ip_id++;
28 : return (ip_id);
29 : } */
30 :
31 : u16
32 0 : udp_ip4_checksum (const void *b, u32 len, u8 * src, u8 * dst)
33 : {
34 0 : const u16 *buf = b;
35 0 : u16 *ip_src = (u16 *) src;
36 0 : u16 *ip_dst = (u16 *) dst;
37 0 : u32 length = len;
38 0 : u32 sum = 0;
39 :
40 0 : while (len > 1)
41 : {
42 0 : sum += *buf++;
43 0 : if (sum & 0x80000000)
44 0 : sum = (sum & 0xFFFF) + (sum >> 16);
45 0 : len -= 2;
46 : }
47 :
48 : /* Add the padding if the packet length is odd */
49 0 : if (len & 1)
50 0 : sum += *((u8 *) buf);
51 :
52 : /* Add the pseudo-header */
53 0 : sum += *(ip_src++);
54 0 : sum += *ip_src;
55 :
56 0 : sum += *(ip_dst++);
57 0 : sum += *ip_dst;
58 :
59 0 : sum += clib_host_to_net_u16 (IP_PROTOCOL_UDP);
60 0 : sum += clib_host_to_net_u16 (length);
61 :
62 : /* Add the carries */
63 0 : while (sum >> 16)
64 0 : sum = (sum & 0xFFFF) + (sum >> 16);
65 :
66 : /* Return the one's complement of sum */
67 0 : return ((u16) (~sum));
68 : }
69 :
70 : u16
71 0 : udp_ip6_checksum (ip6_header_t * ip6, udp_header_t * up, u32 len)
72 : {
73 : size_t i;
74 : register const u16 *sp;
75 : u32 sum;
76 : union
77 : {
78 : struct
79 : {
80 : ip6_address_t ph_src;
81 : ip6_address_t ph_dst;
82 : u32 ph_len;
83 : u8 ph_zero[3];
84 : u8 ph_nxt;
85 : } ph;
86 : u16 pa[20];
87 : } phu;
88 :
89 : /* pseudo-header */
90 0 : clib_memset (&phu, 0, sizeof (phu));
91 0 : phu.ph.ph_src = ip6->src_address;
92 0 : phu.ph.ph_dst = ip6->dst_address;
93 0 : phu.ph.ph_len = clib_host_to_net_u32 (len);
94 0 : phu.ph.ph_nxt = IP_PROTOCOL_UDP;
95 :
96 0 : sum = 0;
97 0 : for (i = 0; i < sizeof (phu.pa) / sizeof (phu.pa[0]); i++)
98 0 : sum += phu.pa[i];
99 :
100 0 : sp = (const u16 *) up;
101 :
102 0 : for (i = 0; i < (len & ~1); i += 2)
103 0 : sum += *sp++;
104 :
105 0 : if (len & 1)
106 0 : sum += clib_host_to_net_u16 ((*(const u8 *) sp) << 8);
107 :
108 0 : while (sum > 0xffff)
109 0 : sum = (sum & 0xffff) + (sum >> 16);
110 0 : sum = ~sum & 0xffff;
111 :
112 0 : return (sum);
113 : }
114 :
115 : u16
116 0 : udp_checksum (udp_header_t * uh, u32 udp_len, void *ih, u8 version)
117 : {
118 0 : switch (version)
119 : {
120 0 : case AF_IP4:
121 0 : return (udp_ip4_checksum (uh, udp_len,
122 0 : ((ip4_header_t *) ih)->src_address.as_u8,
123 0 : ((ip4_header_t *) ih)->dst_address.as_u8));
124 0 : case AF_IP6:
125 0 : return (udp_ip6_checksum (ih, uh, udp_len));
126 0 : default:
127 0 : return ~0;
128 : }
129 : }
130 :
131 : void *
132 0 : pkt_push_udp (vlib_main_t * vm, vlib_buffer_t * b, u16 sp, u16 dp)
133 : {
134 : udp_header_t *uh;
135 0 : u16 udp_len = sizeof (udp_header_t) + vlib_buffer_length_in_chain (vm, b);
136 :
137 0 : uh = vlib_buffer_push_uninit (b, sizeof (*uh));
138 :
139 0 : uh->src_port = clib_host_to_net_u16 (sp);
140 0 : uh->dst_port = clib_host_to_net_u16 (dp);
141 0 : uh->length = clib_host_to_net_u16 (udp_len);
142 0 : uh->checksum = 0;
143 0 : return uh;
144 : }
145 :
146 : void *
147 0 : pkt_push_ip (vlib_main_t * vm, vlib_buffer_t * b, ip_address_t * src,
148 : ip_address_t * dst, u32 proto, u8 csum_offload)
149 : {
150 0 : if (ip_addr_version (src) != ip_addr_version (dst))
151 : {
152 0 : clib_warning ("src %U and dst %U IP have different AFI! Discarding!",
153 : format_ip_address, src, format_ip_address, dst);
154 0 : return 0;
155 : }
156 :
157 0 : switch (ip_addr_version (src))
158 : {
159 0 : case AF_IP4:
160 0 : return vlib_buffer_push_ip4 (vm, b, &ip_addr_v4 (src),
161 : &ip_addr_v4 (dst), proto, csum_offload);
162 : break;
163 0 : case AF_IP6:
164 0 : return vlib_buffer_push_ip6 (vm, b, &ip_addr_v6 (src),
165 : &ip_addr_v6 (dst), proto);
166 : break;
167 : }
168 :
169 0 : return 0;
170 : }
171 :
172 : void *
173 0 : pkt_push_udp_and_ip (vlib_main_t * vm, vlib_buffer_t * b, u16 sp, u16 dp,
174 : ip_address_t * sip, ip_address_t * dip, u8 csum_offload)
175 : {
176 : u16 udpsum;
177 : udp_header_t *uh;
178 : void *ih;
179 :
180 0 : uh = pkt_push_udp (vm, b, sp, dp);
181 :
182 0 : if (csum_offload)
183 : {
184 0 : ih = pkt_push_ip (vm, b, sip, dip, IP_PROTOCOL_UDP, 1);
185 0 : vnet_buffer_offload_flags_set (b, VNET_BUFFER_OFFLOAD_F_UDP_CKSUM);
186 0 : vnet_buffer (b)->l3_hdr_offset = (u8 *) ih - b->data;
187 0 : vnet_buffer (b)->l4_hdr_offset = (u8 *) uh - b->data;
188 0 : uh->checksum = 0;
189 : }
190 : else
191 : {
192 0 : ih = pkt_push_ip (vm, b, sip, dip, IP_PROTOCOL_UDP, 0);
193 0 : udpsum = udp_checksum (uh, clib_net_to_host_u16 (uh->length), ih,
194 0 : ip_addr_version (sip));
195 0 : if (udpsum == (u16) ~ 0)
196 : {
197 0 : clib_warning ("Failed UDP checksum! Discarding");
198 0 : return 0;
199 : }
200 : /* clear flags used for csum since we're not offloading */
201 0 : b->flags &= ~(VNET_BUFFER_F_IS_IP4 | VNET_BUFFER_F_IS_IP6);
202 0 : uh->checksum = udpsum;
203 : }
204 0 : return ih;
205 : }
206 :
207 : void *
208 0 : pkt_push_ecm_hdr (vlib_buffer_t * b)
209 : {
210 : ecm_hdr_t *h;
211 0 : h = vlib_buffer_push_uninit (b, sizeof (h[0]));
212 :
213 0 : clib_memset (h, 0, sizeof (h[0]));
214 0 : h->type = LISP_ENCAP_CONTROL_TYPE;
215 0 : clib_memset (h->reserved2, 0, sizeof (h->reserved2));
216 :
217 0 : return h;
218 : }
219 :
220 : /* *INDENT-ON* */
221 :
222 : /*
223 : * fd.io coding-style-patch-verification: ON
224 : *
225 : * Local Variables:
226 : * eval: (c-set-style "gnu")
227 : * End:
228 : */
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