1 /* Shared library add-on to iptables for DSCP
2 *
3 * (C) 2000- 2002 by Matthew G. Marsh <mgm@paktronix.com>,
4 * Harald Welte <laforge@gnumonks.org>
5 *
6 * This program is distributed under the terms of GNU GPL v2, 1991
7 *
8 * libipt_DSCP.c borrowed heavily from libipt_TOS.c
9 *
10 * --set-class added by Iain Barnes
11 */
12 #include <stdio.h>
13 #include <string.h>
14 #include <stdlib.h>
15 #include <getopt.h>
16
17 #include <iptables.h>
18 #include <linux/netfilter_ipv4/ip_tables.h>
19 #include <linux/netfilter_ipv4/ipt_DSCP.h>
20
21 /* This is evil, but it's my code - HW*/
22 #include "libipt_dscp_helper.c"
23
24
init(struct ipt_entry_target * t,unsigned int * nfcache)25 static void init(struct ipt_entry_target *t, unsigned int *nfcache)
26 {
27 }
28
help(void)29 static void help(void)
30 {
31 printf(
32 "DSCP target options\n"
33 " --set-dscp value Set DSCP field in packet header to value\n"
34 " This value can be in decimal (ex: 32)\n"
35 " or in hex (ex: 0x20)\n"
36 " --set-dscp-class class Set the DSCP field in packet header to the\n"
37 " value represented by the DiffServ class value.\n"
38 " This class may be EF,BE or any of the CSxx\n"
39 " or AFxx classes.\n"
40 "\n"
41 " These two options are mutually exclusive !\n"
42 );
43 }
44
45 static struct option opts[] = {
46 { "set-dscp", 1, 0, 'F' },
47 { "set-dscp-class", 1, 0, 'G' },
48 { 0 }
49 };
50
51 static void
parse_dscp(const char * s,struct ipt_DSCP_info * dinfo)52 parse_dscp(const char *s, struct ipt_DSCP_info *dinfo)
53 {
54 unsigned int dscp;
55
56 if (string_to_number(s, 0, 255, &dscp) == -1)
57 exit_error(PARAMETER_PROBLEM,
58 "Invalid dscp `%s'\n", s);
59
60 if (dscp > IPT_DSCP_MAX)
61 exit_error(PARAMETER_PROBLEM,
62 "DSCP `%d` out of range\n", dscp);
63
64 dinfo->dscp = (u_int8_t )dscp;
65 return;
66 }
67
68
69 static void
parse_class(const char * s,struct ipt_DSCP_info * dinfo)70 parse_class(const char *s, struct ipt_DSCP_info *dinfo)
71 {
72 unsigned int dscp = class_to_dscp(s);
73
74 /* Assign the value */
75 dinfo->dscp = (u_int8_t)dscp;
76 }
77
78
79 static int
parse(int c,char ** argv,int invert,unsigned int * flags,const struct ipt_entry * entry,struct ipt_entry_target ** target)80 parse(int c, char **argv, int invert, unsigned int *flags,
81 const struct ipt_entry *entry,
82 struct ipt_entry_target **target)
83 {
84 struct ipt_DSCP_info *dinfo
85 = (struct ipt_DSCP_info *)(*target)->data;
86
87 switch (c) {
88 case 'F':
89 if (*flags)
90 exit_error(PARAMETER_PROBLEM,
91 "DSCP target: Only use --set-dscp ONCE!");
92 parse_dscp(optarg, dinfo);
93 *flags = 1;
94 break;
95 case 'G':
96 if (*flags)
97 exit_error(PARAMETER_PROBLEM,
98 "DSCP target: Only use --set-dscp-class ONCE!");
99 parse_class(optarg, dinfo);
100 *flags = 1;
101 break;
102
103 default:
104 return 0;
105 }
106
107 return 1;
108 }
109
110 static void
final_check(unsigned int flags)111 final_check(unsigned int flags)
112 {
113 if (!flags)
114 exit_error(PARAMETER_PROBLEM,
115 "DSCP target: Parameter --set-dscp is required");
116 }
117
118 static void
print_dscp(u_int8_t dscp,int numeric)119 print_dscp(u_int8_t dscp, int numeric)
120 {
121 printf("0x%02x ", dscp);
122 }
123
124 /* Prints out the targinfo. */
125 static void
print(const struct ipt_ip * ip,const struct ipt_entry_target * target,int numeric)126 print(const struct ipt_ip *ip,
127 const struct ipt_entry_target *target,
128 int numeric)
129 {
130 const struct ipt_DSCP_info *dinfo =
131 (const struct ipt_DSCP_info *)target->data;
132 printf("DSCP set ");
133 print_dscp(dinfo->dscp, numeric);
134 }
135
136 /* Saves the union ipt_targinfo in parsable form to stdout. */
137 static void
save(const struct ipt_ip * ip,const struct ipt_entry_target * target)138 save(const struct ipt_ip *ip, const struct ipt_entry_target *target)
139 {
140 const struct ipt_DSCP_info *dinfo =
141 (const struct ipt_DSCP_info *)target->data;
142
143 printf("--set-dscp 0x%02x ", dinfo->dscp);
144 }
145
146 static struct iptables_target dscp = {
147 .next = NULL,
148 .name = "DSCP",
149 .version = IPTABLES_VERSION,
150 .size = IPT_ALIGN(sizeof(struct ipt_DSCP_info)),
151 .userspacesize = IPT_ALIGN(sizeof(struct ipt_DSCP_info)),
152 .help = &help,
153 .init = &init,
154 .parse = &parse,
155 .final_check = &final_check,
156 .print = &print,
157 .save = &save,
158 .extra_opts = opts
159 };
160
ipt_DSCP_init(void)161 void ipt_DSCP_init(void)
162 {
163 register_target(&dscp);
164 }
165