Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 1 | /* Shared library add-on to iptables to add TCPMSS target support. |
| 2 | * |
| 3 | * Copyright (c) 2000 Marc Boucher |
| 4 | */ |
| 5 | #include <stdio.h> |
| 6 | #include <string.h> |
| 7 | #include <stdlib.h> |
| 8 | #include <getopt.h> |
| 9 | |
| 10 | #include <xtables.h> |
| 11 | #include <linux/netfilter/x_tables.h> |
| 12 | #include <linux/netfilter/xt_TCPMSS.h> |
| 13 | |
| 14 | struct mssinfo { |
| 15 | struct xt_entry_target t; |
| 16 | struct xt_tcpmss_info mss; |
| 17 | }; |
| 18 | |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 19 | static void __TCPMSS_help(int hdrsize) |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 20 | { |
| 21 | printf( |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 22 | "TCPMSS target mutually-exclusive options:\n" |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 23 | " --set-mss value explicitly set MSS option to specified value\n" |
| 24 | " --clamp-mss-to-pmtu automatically clamp MSS value to (path_MTU - %d)\n", |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 25 | hdrsize); |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 26 | } |
| 27 | |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 28 | static void TCPMSS_help(void) |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 29 | { |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 30 | __TCPMSS_help(40); |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 31 | } |
| 32 | |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 33 | static void TCPMSS_help6(void) |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 34 | { |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 35 | __TCPMSS_help(60); |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 36 | } |
| 37 | |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 38 | static const struct option TCPMSS_opts[] = { |
Patrick McHardy | 500f483 | 2007-09-08 15:59:04 +0000 | [diff] [blame] | 39 | { "set-mss", 1, NULL, '1' }, |
| 40 | { "clamp-mss-to-pmtu", 0, NULL, '2' }, |
Max Kellermann | 9ee386a | 2008-01-29 13:48:05 +0000 | [diff] [blame] | 41 | { .name = NULL } |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 42 | }; |
| 43 | |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 44 | static int __TCPMSS_parse(int c, char **argv, int invert, unsigned int *flags, |
| 45 | const void *entry, struct xt_entry_target **target, |
| 46 | int hdrsize) |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 47 | { |
| 48 | struct xt_tcpmss_info *mssinfo |
| 49 | = (struct xt_tcpmss_info *)(*target)->data; |
| 50 | |
| 51 | switch (c) { |
| 52 | unsigned int mssval; |
| 53 | |
| 54 | case '1': |
| 55 | if (*flags) |
| 56 | exit_error(PARAMETER_PROBLEM, |
| 57 | "TCPMSS target: Only one option may be specified"); |
Jan Engelhardt | 5f2922c | 2009-01-27 18:43:01 +0100 | [diff] [blame] | 58 | if (!xtables_strtoui(optarg, NULL, &mssval, |
| 59 | 0, UINT16_MAX - hdrsize)) |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 60 | exit_error(PARAMETER_PROBLEM, "Bad TCPMSS value `%s'", optarg); |
| 61 | |
| 62 | mssinfo->mss = mssval; |
| 63 | *flags = 1; |
| 64 | break; |
| 65 | |
| 66 | case '2': |
| 67 | if (*flags) |
| 68 | exit_error(PARAMETER_PROBLEM, |
| 69 | "TCPMSS target: Only one option may be specified"); |
| 70 | mssinfo->mss = XT_TCPMSS_CLAMP_PMTU; |
| 71 | *flags = 1; |
| 72 | break; |
| 73 | |
| 74 | default: |
| 75 | return 0; |
| 76 | } |
| 77 | |
| 78 | return 1; |
| 79 | } |
| 80 | |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 81 | static int TCPMSS_parse(int c, char **argv, int invert, unsigned int *flags, |
| 82 | const void *entry, struct xt_entry_target **target) |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 83 | { |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 84 | return __TCPMSS_parse(c, argv, invert, flags, entry, target, 40); |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 85 | } |
| 86 | |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 87 | static int TCPMSS_parse6(int c, char **argv, int invert, unsigned int *flags, |
| 88 | const void *entry, struct xt_entry_target **target) |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 89 | { |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 90 | return __TCPMSS_parse(c, argv, invert, flags, entry, target, 60); |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 91 | } |
| 92 | |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 93 | static void TCPMSS_check(unsigned int flags) |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 94 | { |
| 95 | if (!flags) |
| 96 | exit_error(PARAMETER_PROBLEM, |
| 97 | "TCPMSS target: At least one parameter is required"); |
| 98 | } |
| 99 | |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 100 | static void TCPMSS_print(const void *ip, const struct xt_entry_target *target, |
| 101 | int numeric) |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 102 | { |
| 103 | const struct xt_tcpmss_info *mssinfo = |
| 104 | (const struct xt_tcpmss_info *)target->data; |
| 105 | if(mssinfo->mss == XT_TCPMSS_CLAMP_PMTU) |
| 106 | printf("TCPMSS clamp to PMTU "); |
| 107 | else |
| 108 | printf("TCPMSS set %u ", mssinfo->mss); |
| 109 | } |
| 110 | |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 111 | static void TCPMSS_save(const void *ip, const struct xt_entry_target *target) |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 112 | { |
| 113 | const struct xt_tcpmss_info *mssinfo = |
| 114 | (const struct xt_tcpmss_info *)target->data; |
| 115 | |
| 116 | if(mssinfo->mss == XT_TCPMSS_CLAMP_PMTU) |
| 117 | printf("--clamp-mss-to-pmtu "); |
| 118 | else |
| 119 | printf("--set-mss %u ", mssinfo->mss); |
| 120 | } |
| 121 | |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 122 | static struct xtables_target tcpmss_target = { |
Jan Engelhardt | 03d9948 | 2008-11-18 12:27:54 +0100 | [diff] [blame] | 123 | .family = NFPROTO_IPV4, |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 124 | .name = "TCPMSS", |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 125 | .version = XTABLES_VERSION, |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 126 | .size = XT_ALIGN(sizeof(struct xt_tcpmss_info)), |
| 127 | .userspacesize = XT_ALIGN(sizeof(struct xt_tcpmss_info)), |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 128 | .help = TCPMSS_help, |
| 129 | .parse = TCPMSS_parse, |
| 130 | .final_check = TCPMSS_check, |
| 131 | .print = TCPMSS_print, |
| 132 | .save = TCPMSS_save, |
| 133 | .extra_opts = TCPMSS_opts, |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 134 | }; |
| 135 | |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 136 | static struct xtables_target tcpmss_target6 = { |
Jan Engelhardt | 03d9948 | 2008-11-18 12:27:54 +0100 | [diff] [blame] | 137 | .family = NFPROTO_IPV6, |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 138 | .name = "TCPMSS", |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 139 | .version = XTABLES_VERSION, |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 140 | .size = XT_ALIGN(sizeof(struct xt_tcpmss_info)), |
| 141 | .userspacesize = XT_ALIGN(sizeof(struct xt_tcpmss_info)), |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 142 | .help = TCPMSS_help6, |
| 143 | .parse = TCPMSS_parse6, |
| 144 | .final_check = TCPMSS_check, |
| 145 | .print = TCPMSS_print, |
| 146 | .save = TCPMSS_save, |
| 147 | .extra_opts = TCPMSS_opts, |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 148 | }; |
| 149 | |
| 150 | void _init(void) |
| 151 | { |
Jan Engelhardt | 932e648 | 2007-10-04 16:27:30 +0000 | [diff] [blame] | 152 | xtables_register_target(&tcpmss_target); |
| 153 | xtables_register_target(&tcpmss_target6); |
Yasuyuki KOZAKAI | 45e4c69 | 2007-07-24 07:22:24 +0000 | [diff] [blame] | 154 | } |