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 #include <sys/types.h>
28 #include <sys/atomic.h>
29 #include <sys/pattr.h>
30 #include <netinet/in.h>
31 #include <netinet/ip6.h>
32 #include <inet/common.h>
33 #include <inet/ip.h>
34 #include <inet/ip6.h>
35 #include <ipp/dscpmk/dscpmk_impl.h>
36
37 /* Module to mark the ToS/DS field for a given packet */
38
39 /* Debug level */
40 int dscpmk_debug = 0;
41
42 /*
43 * Given a packet, this routine marks the ToS or DSCP for IPv4 and IPv6 resp.
44 * using the configured dscp_map.
45 * Note that this module does not change the ECN bits.
46 */
47 int
48 dscpmk_process(mblk_t **mpp, dscpmk_data_t *dscpmk_data, ip_proc_t proc)
49 {
50 ipha_t *ipha;
51 ip6_t *ip6_hdr;
52 boolean_t is_v4;
53 uint8_t dscp, new_dscp;
54 mblk_t *mp;
55
56 ASSERT((mpp != NULL) && (*mpp != NULL));
57 mp = *mpp;
58
59 /*
60 * The action module will receive an M_DATA or an M_CTL followed
61 * by an M_DATA. In the latter case skip the M_CTL.
62 */
63 if (mp->b_datap->db_type != M_DATA) {
64 if ((mp->b_cont != NULL) &&
65 (mp->b_cont->b_datap->db_type == M_DATA)) {
66 mp = mp->b_cont;
67 } else {
68 dscpmk0dbg(("dscpmk_process: no data\n"));
69 atomic_inc_64(&dscpmk_data->epackets);
70 return (EINVAL);
71 }
72 }
73
74 /* Pull-up needed? */
75 if ((mp->b_wptr - mp->b_rptr) < IP_SIMPLE_HDR_LENGTH) {
76 if (!pullupmsg(mp, IP_SIMPLE_HDR_LENGTH)) {
77 dscpmk0dbg(("dscpmk_process: pullup failed\n"));
78 atomic_inc_64(&dscpmk_data->epackets);
79 return (EINVAL);
80 }
81 }
82 ipha = (ipha_t *)mp->b_rptr;
83
84 /* Update global stats */
85 atomic_inc_64(&dscpmk_data->npackets);
86
87 /*
88 * This should only be called for outgoing packets. For inbound packets
89 * proceed with the next action.
90 */
91 if ((proc == IPP_LOCAL_IN) || (proc == IPP_FWD_IN)) {
92 dscpmk2dbg(("dscpmk_process: cannot mark incoming packets\n"));
93 atomic_inc_64(&dscpmk_data->ipackets);
94 return (0);
95 }
96
97 /* Figure out the ToS or the Traffic Class from the message */
98 if (IPH_HDR_VERSION(ipha) == IPV4_VERSION) {
99 dscp = ipha->ipha_type_of_service;
100 is_v4 = B_TRUE;
101 } else {
102 ip6_hdr = (ip6_t *)mp->b_rptr;
103 dscp = __IPV6_TCLASS_FROM_FLOW(ip6_hdr->ip6_vcf);
104 is_v4 = B_FALSE;
105 }
106
107 /*
108 * Select the new dscp from the dscp_map after ignoring the
109 * ECN/CU from dscp (hence dscp >> 2). new_dscp will be the
110 * 6-bit DSCP value.
111 */
112 new_dscp = dscpmk_data->dscp_map[dscp >> 2];
113
114 /* Update stats for this new_dscp */
115 atomic_inc_64(&dscpmk_data->dscp_stats[new_dscp].npackets);
116
117 /*
118 * if new_dscp is same as the original, update stats and
119 * return.
120 */
121 if (new_dscp == (dscp >> 2)) {
122 atomic_inc_64(&dscpmk_data->unchanged);
123 return (0);
124 }
125
126 /* Get back the ECN/CU value from the original dscp */
127 new_dscp = (new_dscp << 2) | (dscp & 0x3);
128
129 atomic_inc_64(&dscpmk_data->changed);
130 /*
131 * IPv4 : ToS structure -- RFC 791
132 *
133 * 0 1 2 3 4 5 6 7
134 * +---+---+---+---+---+---+---+---+
135 * | IP Precd | D | T | R | 0 | 0 |
136 * | | | | | | |
137 * +---+---+---+---+---+---+---+---+
138 *
139 * For Backward Compatability the diff serv DSCP will be mapped
140 * to the 3-bits Precedence field. DTR is not supported. Thus,
141 * the following Class Seletor CodePoints are reserved from this
142 * purpose : xxx000; where x is 0 or 1 (note the last 2 bits are
143 * 00) -- see RFC 2474.
144 */
145
146 if (is_v4) {
147 ipha->ipha_type_of_service = new_dscp;
148 /*
149 * If the hardware supports checksumming, we don't need
150 * to do anything.
151 */
152 if (!(mp->b_datap->db_struioun.cksum.flags &
153 HCK_IPV4_HDRCKSUM)) {
154 ipha->ipha_hdr_checksum = 0;
155 ipha->ipha_hdr_checksum = ip_csum_hdr(ipha);
156 }
157 } else {
158
159 /*
160 * IPv6 : DSCP field structure is as given -- RFC 2474
161 *
162 * 0 1 2 3 4 5 6 7
163 * +---+---+---+---+---+---+---+---+
164 * | DSCP | CU |
165 * | | |
166 * +---+---+---+---+---+---+---+---+
167 *
168 * CU -- Currently Unused
169 *
170 * the 32 bit vcf consists of version (4 bits), Traffic class (8 bits)
171 * and flow id (20 bits). Need to take care of Big/Little-Endianess.
172 */
173 #ifdef _BIG_ENDIAN
174 ip6_hdr->ip6_vcf = (ip6_hdr->ip6_vcf & TCLASS_MASK) |
175 (new_dscp << 20);
176 #else
177 ip6_hdr->ip6_vcf = (ip6_hdr->ip6_vcf & TCLASS_MASK) |
178 ((new_dscp >> 4) | ((new_dscp << 12) & 0xF000));
179 #endif
180 }
181
182 return (0);
183 }