1 /* Shared library add-on to iptables for DSCP
2 *
3 * (C) 2002 by Harald Welte <laforge@gnumonks.org>
4 *
5 * This program is distributed under the terms of GNU GPL v2, 1991
6 *
7 * libipt_dscp.c borrowed heavily from libipt_tos.c
8 *
9 * --class support added by Iain Barnes
10 *
11 * For a list of DSCP codepoints see
12 * http://www.iana.org/assignments/dscp-registry
13 *
14 */
15 #include <stdio.h>
16 #include <string.h>
17 #include <stdlib.h>
18 #include <getopt.h>
19
20 #include <iptables.h>
21 #include <linux/netfilter_ipv4/ip_tables.h>
22 #include <linux/netfilter_ipv4/ipt_2dscp.h>
23
24 /* This is evil, but it's my code - HW*/
25 #include "libipt_dscp_helper.c"
26
help(void)27 static void help(void)
28 {
29 printf(
30 "DSCP match v%s options\n"
31 "[!] --dscp value Match DSCP codepoint with numerical value\n"
32 " This value can be in decimal (ex: 32)\n"
33 " or in hex (ex: 0x20)\n"
34 "[!] --dscp-class name Match the DiffServ class. This value may\n"
35 " be any of the BE,EF, AFxx or CSx classes\n"
36 "\n"
37 " These two options are mutually exclusive !\n"
38 , IPTABLES_VERSION
39 );
40 }
41
42 static struct option opts[] = {
43 { "dscp", 1, 0, 'F' },
44 { "dscp-class", 1, 0, 'G' },
45 { 0 }
46 };
47
48 static void
parse_dscp(const char * s,struct ipt_dscp_info * dinfo)49 parse_dscp(const char *s, struct ipt_dscp_info *dinfo)
50 {
51 unsigned int dscp;
52
53 if (string_to_number(s, 0, 255, &dscp) == -1)
54 exit_error(PARAMETER_PROBLEM,
55 "Invalid dscp `%s'\n", s);
56
57 if (dscp > IPT_DSCP_MAX)
58 exit_error(PARAMETER_PROBLEM,
59 "DSCP `%d` out of range\n", dscp);
60
61 dinfo->dscp = (u_int8_t )dscp;
62 return;
63 }
64
65
66 static void
parse_class(const char * s,struct ipt_dscp_info * dinfo)67 parse_class(const char *s, struct ipt_dscp_info *dinfo)
68 {
69 unsigned int dscp = class_to_dscp(s);
70
71 /* Assign the value */
72 dinfo->dscp = (u_int8_t)dscp;
73 }
74
75
76 static int
parse(int c,char ** argv,int invert,unsigned int * flags,const struct ipt_entry * entry,unsigned int * nfcache,struct ipt_entry_match ** match)77 parse(int c, char **argv, int invert, unsigned int *flags,
78 const struct ipt_entry *entry,
79 unsigned int *nfcache,
80 struct ipt_entry_match **match)
81 {
82 struct ipt_dscp_info *dinfo
83 = (struct ipt_dscp_info *)(*match)->data;
84
85 switch (c) {
86 case 'F':
87 if (*flags)
88 exit_error(PARAMETER_PROBLEM,
89 "DSCP match: Only use --dscp ONCE!");
90 check_inverse(optarg, &invert, &optind, 0);
91 parse_dscp(argv[optind-1], dinfo);
92 if (invert)
93 dinfo->invert = 1;
94 *flags = 1;
95 break;
96
97 case 'G':
98 if (*flags)
99 exit_error(PARAMETER_PROBLEM,
100 "DSCP match: Only use --dscp-class ONCE!");
101 check_inverse(optarg, &invert, &optind, 0);
102 parse_class(argv[optind - 1], dinfo);
103 if (invert)
104 dinfo->invert = 1;
105 *flags = 1;
106 break;
107
108 default:
109 return 0;
110 }
111
112 return 1;
113 }
114
115 static void
final_check(unsigned int flags)116 final_check(unsigned int flags)
117 {
118 if (!flags)
119 exit_error(PARAMETER_PROBLEM,
120 "DSCP match: Parameter --dscp is required");
121 }
122
123 static void
print_dscp(u_int8_t dscp,int invert,int numeric)124 print_dscp(u_int8_t dscp, int invert, int numeric)
125 {
126 if (invert)
127 fputc('!', stdout);
128
129 printf("0x%02x ", dscp);
130 }
131
132 /* Prints out the matchinfo. */
133 static void
print(const struct ipt_ip * ip,const struct ipt_entry_match * match,int numeric)134 print(const struct ipt_ip *ip,
135 const struct ipt_entry_match *match,
136 int numeric)
137 {
138 const struct ipt_dscp_info *dinfo =
139 (const struct ipt_dscp_info *)match->data;
140 printf("DSCP match ");
141 print_dscp(dinfo->dscp, dinfo->invert, numeric);
142 }
143
144 /* Saves the union ipt_matchinfo in parsable form to stdout. */
145 static void
save(const struct ipt_ip * ip,const struct ipt_entry_match * match)146 save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
147 {
148 const struct ipt_dscp_info *dinfo =
149 (const struct ipt_dscp_info *)match->data;
150
151 printf("--dscp ");
152 print_dscp(dinfo->dscp, dinfo->invert, 1);
153 }
154
155 static struct iptables_match dscp = {
156 .next = NULL,
157 .name = "dscp",
158 .version = IPTABLES_VERSION,
159 .size = IPT_ALIGN(sizeof(struct ipt_dscp_info)),
160 .userspacesize = IPT_ALIGN(sizeof(struct ipt_dscp_info)),
161 .help = &help,
162 .parse = &parse,
163 .final_check = &final_check,
164 .print = &print,
165 .save = &save,
166 .extra_opts = opts
167 };
168
ipt_2dscp_init(void)169 void ipt_2dscp_init(void)
170 {
171 register_match(&dscp);
172 }
173