This patch adds a new exetension to iptables to supprt 'srh' match The implementation considers revision 7 of the SRH draft. https://tools.ietf.org/html/draft-ietf-6man-segment-routing-header-07 Signed-off-by: Ahmed Abdelsalam <amsalam20@xxxxxxxxx> --- extensions/libip6t_srh.c | 242 ++++++++++++++++++++++++++++++++ extensions/libip6t_srh.t | 26 ++++ include/linux/netfilter_ipv6/ip6t_srh.h | 56 ++++++++ 3 files changed, 324 insertions(+) create mode 100644 extensions/libip6t_srh.c create mode 100644 extensions/libip6t_srh.t create mode 100644 include/linux/netfilter_ipv6/ip6t_srh.h diff --git a/extensions/libip6t_srh.c b/extensions/libip6t_srh.c new file mode 100644 index 0000000..ac0ae08 --- /dev/null +++ b/extensions/libip6t_srh.c @@ -0,0 +1,242 @@ +/* Shared library to add Segment Routing Header (SRH) matching support. + * + * Author: + * Ahmed Abdelsalam <amsalam20@xxxxxxxxx> + */ + +#include <stdio.h> +#include <xtables.h> +#include <linux/netfilter_ipv6/ip6t_srh.h> +#include <string.h> + +/* srh command-line options */ +enum { + O_SRH_NEXTHDR, + O_SRH_LEN_EQ, + O_SRH_LEN_GT, + O_SRH_LEN_LT, + O_SRH_SEGS_EQ, + O_SRH_SEGS_GT, + O_SRH_SEGS_LT, + O_SRH_LAST_EQ, + O_SRH_LAST_GT, + O_SRH_LAST_LT, + O_SRH_TAG, +}; + +static void srh_help(void) +{ + printf( +"srh match options:\n" +"[!] --srh-next-hdr next-hdr Next Header value of SRH\n" +"[!] --srh-hdr-len-eq hdr_len Hdr Ext Len value of SRH\n" +"[!] --srh-hdr-len-gt hdr_len Hdr Ext Len value of SRH\n" +"[!] --srh-hdr-len-lt hdr_len Hdr Ext Len value of SRH\n" +"[!] --srh-segs-left-eq segs_left Segments Left value of SRH\n" +"[!] --srh-segs-left-gt segs_left Segments Left value of SRH\n" +"[!] --srh-segs-left-lt segs_left Segments Left value of SRH\n" +"[!] --srh-last-entry-eq last_entry Last Entry value of SRH\n" +"[!] --srh-last-entry-gt last_entry Last Entry value of SRH\n" +"[!] --srh-last-entry-lt last_entry Last Entry value of SRH\n" +"[!] --srh-tag tag Tag value of SRH\n"); +} + +#define s struct ip6t_srh +static const struct xt_option_entry srh_opts[] = { + { .name = "srh-next-hdr", .id = O_SRH_NEXTHDR, .type = XTTYPE_UINT8, + .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, next_hdr)}, + { .name = "srh-hdr-len-eq", .id = O_SRH_LEN_EQ, .type = XTTYPE_UINT8, + .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, hdr_len)}, + { .name = "srh-hdr-len-gt", .id = O_SRH_LEN_GT, .type = XTTYPE_UINT8, + .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, hdr_len)}, + { .name = "srh-hdr-len-lt", .id = O_SRH_LEN_LT, .type = XTTYPE_UINT8, + .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, hdr_len)}, + { .name = "srh-segs-left-eq", .id = O_SRH_SEGS_EQ, .type = XTTYPE_UINT8, + .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, segs_left)}, + { .name = "srh-segs-left-gt", .id = O_SRH_SEGS_GT, .type = XTTYPE_UINT8, + .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, segs_left)}, + { .name = "srh-segs-left-lt", .id = O_SRH_SEGS_LT, .type = XTTYPE_UINT8, + .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, segs_left)}, + { .name = "srh-last-entry-eq", .id = O_SRH_LAST_EQ, .type = XTTYPE_UINT8, + .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, last_entry)}, + { .name = "srh-last-entry-gt", .id = O_SRH_LAST_GT, .type = XTTYPE_UINT8, + .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, last_entry)}, + { .name = "srh-last-entry-lt", .id = O_SRH_LAST_LT, .type = XTTYPE_UINT8, + .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, last_entry)}, + { .name = "srh-tag", .id = O_SRH_TAG, .type = XTTYPE_UINT16, + .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, tag)}, + { } +}; +#undef s + +static void srh_init(struct xt_entry_match *m) +{ + struct ip6t_srh *srhinfo = (void *)m->data; + + srhinfo->mt_flags = 0; + srhinfo->mt_invflags = 0; +} + +static void srh_parse(struct xt_option_call *cb) +{ + struct ip6t_srh *srhinfo = cb->data; + + xtables_option_parse(cb); + switch (cb->entry->id) { + case O_SRH_NEXTHDR: + srhinfo->mt_flags |= IP6T_SRH_NEXTHDR; + if (cb->invert) + srhinfo->mt_invflags |= IP6T_SRH_INV_NEXTHDR; + break; + case O_SRH_LEN_EQ: + srhinfo->mt_flags |= IP6T_SRH_LEN_EQ; + if (cb->invert) + srhinfo->mt_invflags |= IP6T_SRH_INV_LEN_EQ; + break; + case O_SRH_LEN_GT: + srhinfo->mt_flags |= IP6T_SRH_LEN_GT; + if (cb->invert) + srhinfo->mt_invflags |= IP6T_SRH_INV_LEN_GT; + break; + case O_SRH_LEN_LT: + srhinfo->mt_flags |= IP6T_SRH_LEN_LT; + if (cb->invert) + srhinfo->mt_invflags |= IP6T_SRH_INV_LEN_LT; + break; + case O_SRH_SEGS_EQ: + srhinfo->mt_flags |= IP6T_SRH_SEGS_EQ; + if (cb->invert) + srhinfo->mt_invflags |= IP6T_SRH_INV_SEGS_EQ; + break; + case O_SRH_SEGS_GT: + srhinfo->mt_flags |= IP6T_SRH_SEGS_GT; + if (cb->invert) + srhinfo->mt_invflags |= IP6T_SRH_INV_SEGS_GT; + break; + case O_SRH_SEGS_LT: + srhinfo->mt_flags |= IP6T_SRH_SEGS_LT; + if (cb->invert) + srhinfo->mt_invflags |= IP6T_SRH_INV_SEGS_LT; + break; + case O_SRH_LAST_EQ: + srhinfo->mt_flags |= IP6T_SRH_LAST_EQ; + if (cb->invert) + srhinfo->mt_invflags |= IP6T_SRH_INV_LAST_EQ; + break; + case O_SRH_LAST_GT: + srhinfo->mt_flags |= IP6T_SRH_LAST_GT; + if (cb->invert) + srhinfo->mt_invflags |= IP6T_SRH_INV_LAST_GT; + break; + case O_SRH_LAST_LT: + srhinfo->mt_flags |= IP6T_SRH_LAST_LT; + if (cb->invert) + srhinfo->mt_invflags |= IP6T_SRH_INV_LAST_LT; + break; + case O_SRH_TAG: + srhinfo->mt_flags |= IP6T_SRH_TAG; + if (cb->invert) + srhinfo->mt_invflags |= IP6T_SRH_INV_TAG; + break; + } +} + +static void srh_print(const void *ip, const struct xt_entry_match *match, + int numeric) +{ + const struct ip6t_srh *srhinfo = (struct ip6t_srh *)match->data; + + printf(" srh"); + if (srhinfo->mt_flags & IP6T_SRH_NEXTHDR) + printf(" next-hdr:%s%d", srhinfo->mt_invflags & IP6T_SRH_INV_NEXTHDR ? "!" : "", + srhinfo->next_hdr); + if (srhinfo->mt_flags & IP6T_SRH_LEN_EQ) + printf(" hdr-len-eq:%s%d", srhinfo->mt_invflags & IP6T_SRH_INV_LEN_EQ ? "!" : "", + srhinfo->hdr_len); + if (srhinfo->mt_flags & IP6T_SRH_LEN_GT) + printf(" hdr-len-gt:%s%d", srhinfo->mt_invflags & IP6T_SRH_INV_LEN_GT ? "!" : "", + srhinfo->hdr_len); + if (srhinfo->mt_flags & IP6T_SRH_LEN_LT) + printf(" hdr-len-lt:%s%d", srhinfo->mt_invflags & IP6T_SRH_INV_LEN_LT ? "!" : "", + srhinfo->hdr_len); + if (srhinfo->mt_flags & IP6T_SRH_SEGS_EQ) + printf(" segs-left-eq:%s%d", srhinfo->mt_invflags & IP6T_SRH_INV_SEGS_EQ ? "!" : "", + srhinfo->segs_left); + if (srhinfo->mt_flags & IP6T_SRH_SEGS_GT) + printf(" segs-left-gt:%s%d", srhinfo->mt_invflags & IP6T_SRH_INV_SEGS_GT ? "!" : "", + srhinfo->segs_left); + if (srhinfo->mt_flags & IP6T_SRH_SEGS_LT) + printf(" segs-left-lt:%s%d", srhinfo->mt_invflags & IP6T_SRH_INV_SEGS_LT ? "!" : "", + srhinfo->segs_left); + if (srhinfo->mt_flags & IP6T_SRH_LAST_EQ) + printf(" last-entry-eq:%s%d", srhinfo->mt_invflags & IP6T_SRH_INV_LAST_EQ ? "!" : "", + srhinfo->last_entry); + if (srhinfo->mt_flags & IP6T_SRH_LAST_GT) + printf(" last-entry-gt:%s%d", srhinfo->mt_invflags & IP6T_SRH_INV_LAST_GT ? "!" : "", + srhinfo->last_entry); + if (srhinfo->mt_flags & IP6T_SRH_LAST_LT) + printf(" last-entry-lt:%s%d", srhinfo->mt_invflags & IP6T_SRH_INV_LAST_LT ? "!" : "", + srhinfo->last_entry); + if (srhinfo->mt_flags & IP6T_SRH_TAG) + printf(" tag:%s%d", srhinfo->mt_invflags & IP6T_SRH_INV_TAG ? "!" : "", + srhinfo->tag); +} + +static void srh_save(const void *ip, const struct xt_entry_match *match) +{ + const struct ip6t_srh *srhinfo = (struct ip6t_srh *)match->data; + + if (srhinfo->mt_flags & IP6T_SRH_NEXTHDR) + printf("%s --srh-next-hdr %u", (srhinfo->mt_invflags & IP6T_SRH_INV_NEXTHDR) ? " !" : "", + srhinfo->next_hdr); + if (srhinfo->mt_flags & IP6T_SRH_LEN_EQ) + printf("%s --srh-hdr-len-eq %u", (srhinfo->mt_invflags & IP6T_SRH_INV_LEN_EQ) ? " !" : "", + srhinfo->hdr_len); + if (srhinfo->mt_flags & IP6T_SRH_LEN_GT) + printf("%s --srh-hdr-len-gt %u", (srhinfo->mt_invflags & IP6T_SRH_INV_LEN_GT) ? " !" : "", + srhinfo->hdr_len); + if (srhinfo->mt_flags & IP6T_SRH_LEN_LT) + printf("%s --srh-hdr-len-lt %u", (srhinfo->mt_invflags & IP6T_SRH_INV_LEN_LT) ? " !" : "", + srhinfo->hdr_len); + if (srhinfo->mt_flags & IP6T_SRH_SEGS_EQ) + printf("%s --srh-segs-left-eq %u", (srhinfo->mt_invflags & IP6T_SRH_INV_SEGS_EQ) ? " !" : "", + srhinfo->segs_left); + if (srhinfo->mt_flags & IP6T_SRH_SEGS_GT) + printf("%s --srh-segs-left-gt %u", (srhinfo->mt_invflags & IP6T_SRH_INV_SEGS_GT) ? " !" : "", + srhinfo->segs_left); + if (srhinfo->mt_flags & IP6T_SRH_SEGS_LT) + printf("%s --srh-segs-left-lt %u", (srhinfo->mt_invflags & IP6T_SRH_INV_SEGS_LT) ? " !" : "", + srhinfo->segs_left); + if (srhinfo->mt_flags & IP6T_SRH_LAST_EQ) + printf("%s --srh-last-entry-eq %u", (srhinfo->mt_invflags & IP6T_SRH_INV_LAST_EQ) ? " !" : "", + srhinfo->last_entry); + if (srhinfo->mt_flags & IP6T_SRH_LAST_GT) + printf("%s --srh-last-entry-gt %u", (srhinfo->mt_invflags & IP6T_SRH_INV_LAST_GT) ? " !" : "", + srhinfo->last_entry); + if (srhinfo->mt_flags & IP6T_SRH_LAST_LT) + printf("%s --srh-last-entry-lt %u", (srhinfo->mt_invflags & IP6T_SRH_INV_LAST_LT) ? " !" : "", + srhinfo->last_entry); + if (srhinfo->mt_flags & IP6T_SRH_TAG) + printf("%s --srh-tag %u", (srhinfo->mt_invflags & IP6T_SRH_INV_TAG) ? " !" : "", + srhinfo->tag); +} + +static struct xtables_match srh_mt6_reg = { + .name = "srh", + .version = XTABLES_VERSION, + .family = NFPROTO_IPV6, + .size = XT_ALIGN(sizeof(struct ip6t_srh)), + .userspacesize = XT_ALIGN(sizeof(struct ip6t_srh)), + .help = srh_help, + .init = srh_init, + .print = srh_print, + .save = srh_save, + .x6_parse = srh_parse, + .x6_options = srh_opts, +}; + +void +_init(void) +{ + xtables_register_match(&srh_mt6_reg); +} diff --git a/extensions/libip6t_srh.t b/extensions/libip6t_srh.t new file mode 100644 index 0000000..08897d5 --- /dev/null +++ b/extensions/libip6t_srh.t @@ -0,0 +1,26 @@ +:INPUT,FORWARD,OUTPUT +-m srh --srh-next-hdr 17;=;OK +-m srh --srh-hdr-len-eq 8;=;OK +-m srh --srh-hdr-len-gt 8;=;OK +-m srh --srh-hdr-len-lt 8;=;OK +-m srh --srh-segs-left-eq 1;=;OK +-m srh --srh-segs-left-gt 1;=;OK +-m srh --srh-segs-left-lt 1;=;OK +-m srh --srh-last-entry-eq 4;=;OK +-m srh --srh-last-entry-gt 4;=;OK +-m srh --srh-last-entry-lt 4;=;OK +-m srh --srh-tag 0;=;OK +-m srh ! --srh-next-hdr 17;=;OK +-m srh ! --srh-hdr-len-eq 8;=;OK +-m srh ! --srh-hdr-len-gt 8;=;OK +-m srh ! --srh-hdr-len-lt 8;=;OK +-m srh ! --srh-segs-left-eq 1;=;OK +-m srh ! --srh-segs-left-gt 1;=;OK +-m srh ! --srh-segs-left-lt 1;=;OK +-m srh ! --srh-last-entry-eq 4;=;OK +-m srh ! --srh-last-entry-gt 4;=;OK +-m srh ! --srh-last-entry-lt 4;=;OK +-m srh ! --srh-tag 0;=;OK +-m srh --srh-next-hdr 17 --srh-segs-left-eq 1 --srh-last-entry-eq 4 --srh-tag 0;=;OK +-m srh ! --srh-next-hdr 17 ! --srh-segs-left-eq 0 --srh-tag 0;=;OK +-m srh;=;OK diff --git a/include/linux/netfilter_ipv6/ip6t_srh.h b/include/linux/netfilter_ipv6/ip6t_srh.h new file mode 100644 index 0000000..087efa1 --- /dev/null +++ b/include/linux/netfilter_ipv6/ip6t_srh.h @@ -0,0 +1,56 @@ +#ifndef _IP6T_SRH_H +#define _IP6T_SRH_H + +#include <linux/types.h> +#include <linux/netfilter.h> + +/* Values for "mt_flags" field in struct ip6t_srh */ +#define IP6T_SRH_NEXTHDR 0x0001 +#define IP6T_SRH_LEN_EQ 0x0002 +#define IP6T_SRH_LEN_GT 0x0004 +#define IP6T_SRH_LEN_LT 0x0008 +#define IP6T_SRH_SEGS_EQ 0x0010 +#define IP6T_SRH_SEGS_GT 0x0020 +#define IP6T_SRH_SEGS_LT 0x0040 +#define IP6T_SRH_LAST_EQ 0x0080 +#define IP6T_SRH_LAST_GT 0x0100 +#define IP6T_SRH_LAST_LT 0x0200 +#define IP6T_SRH_TAG 0x0400 +#define IP6T_SRH_MASK 0x07FF + +/* Values for "mt_invflags" field in struct ip6t_srh */ +#define IP6T_SRH_INV_NEXTHDR 0x0001 +#define IP6T_SRH_INV_LEN_EQ 0x0002 +#define IP6T_SRH_INV_LEN_GT 0x0004 +#define IP6T_SRH_INV_LEN_LT 0x0008 +#define IP6T_SRH_INV_SEGS_EQ 0x0010 +#define IP6T_SRH_INV_SEGS_GT 0x0020 +#define IP6T_SRH_INV_SEGS_LT 0x0040 +#define IP6T_SRH_INV_LAST_EQ 0x0080 +#define IP6T_SRH_INV_LAST_GT 0x0100 +#define IP6T_SRH_INV_LAST_LT 0x0200 +#define IP6T_SRH_INV_TAG 0x0400 +#define IP6T_SRH_INV_MASK 0x07FF + +/** + * struct ip6t_srh - SRH match options + * @ next_hdr: Next header field of SRH + * @ hdr_len: Extension header length field of SRH + * @ segs_left: Segments left field of SRH + * @ last_entry: Last entry field of SRH + * @ tag: Tag field of SRH + * @ mt_flags: match options + * @ mt_invflags: Invert the sense of match options + */ + +struct ip6t_srh { + __u8 next_hdr; + __u8 hdr_len; + __u8 segs_left; + __u8 last_entry; + __u16 tag; + __u16 mt_flags; + __u16 mt_invflags; +}; + +#endif /*_IP6T_SRH_H*/ -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
