1 /*
2 * Copyright (c) 2007 The DragonFly Project. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 * 3. Neither the name of The DragonFly Project nor the names of its
15 * contributors may be used to endorse or promote products derived
16 * from this software without specific, prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
24 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
28 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/param.h>
33 #include <sys/malloc.h> /* for M_NOWAIT */
34 #include <sys/mbuf.h>
35 #include <sys/systm.h>
36
37 #include <net/if_var.h>
38
39 #include <netinet/ip.h>
40
41 #include <netproto/mpls/mpls.h>
42 #include <netproto/mpls/mpls_var.h>
43
44 static int mpls_push(struct mbuf **, mpls_label_t,
45 mpls_s_t, mpls_exp_t, mpls_ttl_t);
46 static int mpls_swap(struct mbuf *, mpls_label_t);
47 static int mpls_pop(struct mbuf *, mpls_s_t *);
48
49 int
mpls_output(struct mbuf * m,struct rtentry * rt)50 mpls_output(struct mbuf *m, struct rtentry *rt)
51 {
52 struct sockaddr_mpls *smpls = NULL;
53 int error = 0, i;
54 mpls_s_t stackempty;
55 mpls_ttl_t ttl = 255;
56 struct ip *ip;
57
58 M_ASSERTPKTHDR(m);
59
60 /*
61 * Check if we are coming from an MPLS routing table lookup.
62 * The rt_key of this rtentry will have a family AF_MPLS if so.
63 */
64 stackempty = rt_key(rt)->sa_family != AF_MPLS ? 1 : 0;
65 if (stackempty) {
66 switch (rt_key(rt)->sa_family) {
67 case AF_INET:
68 ip = mtod(m, struct ip *);
69 ttl = ip->ip_ttl;
70 break;
71 }
72 }
73
74 for (i=0; i < MPLS_MAXLOPS && rt->rt_shim[i] != NULL; ++i) {
75 smpls = (struct sockaddr_mpls *)rt->rt_shim[i];
76 switch (smpls->smpls_op) {
77 case MPLSLOP_PUSH:
78 error = mpls_push(&m,
79 ntohl(smpls->smpls_label),
80 /*
81 * If we are the first label push, then
82 * set the bottom-of-stack bit.
83 */
84 (stackempty && i == 0) ? 1 : 0,
85 0,
86 ttl);
87 if (error)
88 return (error);
89 stackempty = 0;
90 m->m_flags |= M_MPLSLABELED;
91 break;
92 case MPLSLOP_SWAP:
93 /*
94 * Operation is only permmited if label stack
95 * is not empty.
96 */
97 if (stackempty)
98 return (ENOTSUP);
99 KKASSERT(m->m_flags & M_MPLSLABELED);
100 error = mpls_swap(m, ntohl(smpls->smpls_label));
101 if (error)
102 return (error);
103 break;
104 case MPLSLOP_POP:
105 /*
106 * Operation is only permmited if label stack
107 * is not empty.
108 */
109 if (stackempty)
110 return (ENOTSUP);
111 KKASSERT(m->m_flags & M_MPLSLABELED);
112 error = mpls_pop(m, &stackempty);
113 if (error)
114 return (error);
115 /*
116 * If we are popping out the last label then
117 * mark the mbuf as ~M_MPLSLABELED.
118 */
119 if (stackempty)
120 m->m_flags &= ~M_MPLSLABELED;
121 break;
122 default:
123 /* Unknown label operation */
124 return (ENOTSUP);
125 }
126 }
127
128 return (error);
129 }
130
131 /*
132 * Returns FALSE if no further output processing required.
133 */
134 boolean_t
mpls_output_process(struct mbuf * m,struct rtentry * rt)135 mpls_output_process(struct mbuf *m, struct rtentry *rt)
136 {
137 int error;
138
139 /* Does this route have MPLS label operations? */
140 if (!(rt->rt_flags & RTF_MPLSOPS))
141 return TRUE;
142
143 error = mpls_output(m, rt);
144 if (error) {
145 m_freem(m);
146 return FALSE;
147 }
148
149 return TRUE;
150 }
151
152 static int
mpls_push(struct mbuf ** m,mpls_label_t label,mpls_s_t s,mpls_exp_t exp,mpls_ttl_t ttl)153 mpls_push(struct mbuf **m, mpls_label_t label, mpls_s_t s, mpls_exp_t exp, mpls_ttl_t ttl) {
154 struct mpls *mpls;
155 u_int32_t buf = 0; /* Silence warning */
156
157 M_PREPEND(*m, sizeof(struct mpls), M_NOWAIT);
158 if (*m == NULL)
159 return (ENOBUFS);
160
161 MPLS_SET_LABEL(buf, label);
162 MPLS_SET_STACK(buf, s);
163 MPLS_SET_EXP(buf, exp);
164 MPLS_SET_TTL(buf, ttl);
165 mpls = mtod(*m, struct mpls *);
166 mpls->mpls_shim = htonl(buf);
167
168 return (0);
169 }
170
171 static int
mpls_swap(struct mbuf * m,mpls_label_t label)172 mpls_swap(struct mbuf *m, mpls_label_t label) {
173 struct mpls *mpls;
174 u_int32_t buf;
175 mpls_ttl_t ttl;
176
177 if (m->m_len < sizeof(struct mpls) &&
178 (m = m_pullup(m, sizeof(struct mpls))) == NULL)
179 return (ENOBUFS);
180
181 mpls = mtod(m, struct mpls *);
182 buf = ntohl(mpls->mpls_shim);
183 ttl = MPLS_TTL(buf);
184 if (--ttl <= 0) {
185 /* XXX: should send icmp ttl expired. */
186 mplsstat.mplss_ttlexpired++;
187 return (ETIMEDOUT);
188 }
189 MPLS_SET_LABEL(buf, label);
190 MPLS_SET_TTL(buf, ttl); /* XXX tunnel mode: uniform, pipe, short pipe */
191 mpls->mpls_shim = htonl(buf);
192
193 return (0);
194 }
195
196 static int
mpls_pop(struct mbuf * m,mpls_s_t * sbit)197 mpls_pop(struct mbuf *m, mpls_s_t *sbit) {
198 struct mpls *mpls;
199 u_int32_t buf;
200
201 if (m->m_len < sizeof(struct mpls)) {
202 m = m_pullup(m, sizeof(struct mpls));
203 if (m == NULL)
204 return (ENOBUFS);
205 }
206 mpls = mtod(m, struct mpls *);
207 buf = ntohl(mpls->mpls_shim);
208 *sbit = MPLS_STACK(buf);
209
210 m_adj(m, sizeof(struct mpls));
211
212 return (0);
213 }
214