1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 #include <sys/types.h>
30 #include <sys/atomic.h>
31 #include <sys/pattr.h>
32 #include <netinet/in.h>
33 #include <netinet/ip6.h>
34 #include <inet/common.h>
35 #include <inet/ip.h>
36 #include <inet/ip6.h>
37 #include <ipp/dscpmk/dscpmk_impl.h>
38
39 /* Module to mark the ToS/DS field for a given packet */
40
41 /* Debug level */
42 int dscpmk_debug = 0;
43
44 /*
45 * Given a packet, this routine marks the ToS or DSCP for IPv4 and IPv6 resp.
46 * using the configured dscp_map.
47 * Note that this module does not change the ECN bits.
48 */
49 int
50 dscpmk_process(mblk_t **mpp, dscpmk_data_t *dscpmk_data, ip_proc_t proc)
51 {
52 ipha_t *ipha;
53 ip6_t *ip6_hdr;
54 boolean_t is_v4;
55 uint8_t dscp, new_dscp;
56 mblk_t *mp;
57
58 ASSERT((mpp != NULL) && (*mpp != NULL));
59 mp = *mpp;
60
61 /*
62 * The action module will receive an M_DATA or an M_CTL followed
63 * by an M_DATA. In the latter case skip the M_CTL.
64 */
65 if (mp->b_datap->db_type != M_DATA) {
66 if ((mp->b_cont != NULL) &&
67 (mp->b_cont->b_datap->db_type == M_DATA)) {
68 mp = mp->b_cont;
69 } else {
70 dscpmk0dbg(("dscpmk_process: no data\n"));
71 atomic_add_64(&dscpmk_data->epackets, 1);
72 return (EINVAL);
73 }
74 }
75
76 /* Pull-up needed? */
77 if ((mp->b_wptr - mp->b_rptr) < IP_SIMPLE_HDR_LENGTH) {
78 if (!pullupmsg(mp, IP_SIMPLE_HDR_LENGTH)) {
79 dscpmk0dbg(("dscpmk_process: pullup failed\n"));
80 atomic_add_64(&dscpmk_data->epackets, 1);
81 return (EINVAL);
82 }
83 }
84 ipha = (ipha_t *)mp->b_rptr;
85
86 /* Update global stats */
87 atomic_add_64(&dscpmk_data->npackets, 1);
88
89 /*
90 * This should only be called for outgoing packets. For inbound packets
91 * proceed with the next action.
92 */
93 if ((proc == IPP_LOCAL_IN) || (proc == IPP_FWD_IN)) {
94 dscpmk2dbg(("dscpmk_process: cannot mark incoming packets\n"));
95 atomic_add_64(&dscpmk_data->ipackets, 1);
96 return (0);
97 }
98
99 /* Figure out the ToS or the Traffic Class from the message */
100 if (IPH_HDR_VERSION(ipha) == IPV4_VERSION) {
101 dscp = ipha->ipha_type_of_service;
102 is_v4 = B_TRUE;
103 } else {
104 ip6_hdr = (ip6_t *)mp->b_rptr;
105 dscp = __IPV6_TCLASS_FROM_FLOW(ip6_hdr->ip6_vcf);
106 is_v4 = B_FALSE;
107 }
108
109 /*
110 * Select the new dscp from the dscp_map after ignoring the
111 * ECN/CU from dscp (hence dscp >> 2). new_dscp will be the
112 * 6-bit DSCP value.
113 */
114 new_dscp = dscpmk_data->dscp_map[dscp >> 2];
115
116 /* Update stats for this new_dscp */
117 atomic_add_64(&dscpmk_data->dscp_stats[new_dscp].npackets, 1);
118
119 /*
120 * if new_dscp is same as the original, update stats and
121 * return.
122 */
123 if (new_dscp == (dscp >> 2)) {
124 atomic_add_64(&dscpmk_data->unchanged, 1);
125 return (0);
126 }
127
128 /* Get back the ECN/CU value from the original dscp */
129 new_dscp = (new_dscp << 2) | (dscp & 0x3);
130
131 atomic_add_64(&dscpmk_data->changed, 1);
132 /*
133 * IPv4 : ToS structure -- RFC 791
134 *
135 * 0 1 2 3 4 5 6 7
136 * +---+---+---+---+---+---+---+---+
137 * | IP Precd | D | T | R | 0 | 0 |
138 * | | | | | | |
139 * +---+---+---+---+---+---+---+---+
140 *
141 * For Backward Compatability the diff serv DSCP will be mapped
142 * to the 3-bits Precedence field. DTR is not supported. Thus,
143 * the following Class Seletor CodePoints are reserved from this
144 * purpose : xxx000; where x is 0 or 1 (note the last 2 bits are
145 * 00) -- see RFC 2474.
146 */
147
148 if (is_v4) {
149 ipha->ipha_type_of_service = new_dscp;
150 /*
151 * If the hardware supports checksumming, we don't need
152 * to do anything.
153 */
154 if (!(mp->b_datap->db_struioun.cksum.flags &
155 HCK_IPV4_HDRCKSUM)) {
156 ipha->ipha_hdr_checksum = 0;
157 ipha->ipha_hdr_checksum = ip_csum_hdr(ipha);
158 }
159 } else {
160
161 /*
162 * IPv6 : DSCP field structure is as given -- RFC 2474
163 *
164 * 0 1 2 3 4 5 6 7
165 * +---+---+---+---+---+---+---+---+
166 * | DSCP | CU |
167 * | | |
168 * +---+---+---+---+---+---+---+---+
169 *
170 * CU -- Currently Unused
171 *
172 * the 32 bit vcf consists of version (4 bits), Traffic class (8 bits)
173 * and flow id (20 bits). Need to take care of Big/Little-Endianess.
174 */
175 #ifdef _BIG_ENDIAN
176 ip6_hdr->ip6_vcf = (ip6_hdr->ip6_vcf & TCLASS_MASK) |
177 (new_dscp << 20);
178 #else
179 ip6_hdr->ip6_vcf = (ip6_hdr->ip6_vcf & TCLASS_MASK) |
180 ((new_dscp >> 4) | ((new_dscp << 12) & 0xF000));
181 #endif
182 }
183
184 return (0);
185 }