[iptables 1/2] extensions: libip6t_srh: support matching previous, next and last SID

Ahmed Abdelsalam
2018-04-23T10:48:21Z

This patch extends the libip6t_srh shared library to support matching
previous SID, next SID, and last SID.

Signed-off-by: Ahmed Abdelsalam <amsalam20@gmail.com>
---
extensions/libip6t_srh.c | 65 ++++++++++++++++++++++++++++++++-
include/linux/netfilter_ipv6/ip6t_srh.h | 22 ++++++++++-
2 files changed, 84 insertions(+), 3 deletions(-)

diff --git a/extensions/libip6t_srh.c b/extensions/libip6t_srh.c
index ac0ae08..5acc2ee 100644
--- a/extensions/libip6t_srh.c
+++ b/extensions/libip6t_srh.c
@@ -22,6 +22,9 @@ enum {
O_SRH_LAST_GT,
O_SRH_LAST_LT,
O_SRH_TAG,
+ O_SRH_PSID,
+ O_SRH_NSID,
+ O_SRH_LSID,
};

static void srh_help(void)
@@ -38,7 +41,10 @@ static void srh_help(void)
"[!] --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");
+"[!] --srh-tag tag Tag value of SRH\n"
+"[!] --srh-psid addr[/mask] SRH previous SID\n"
+"[!] --srh-nsid addr[/mask] SRH next SID\n"
+"[!] --srh-lsid addr[/mask] SRH Last SID\n");
}

#define s struct ip6t_srh
@@ -65,6 +71,12 @@ static const struct xt_option_entry srh_opts[] = {
.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)},
+ { .name = "srh-psid", .id = O_SRH_PSID, .type = XTTYPE_HOSTMASK,
+ .flags = XTOPT_INVERT},
+ { .name = "srh-nsid", .id = O_SRH_NSID, .type = XTTYPE_HOSTMASK,
+ .flags = XTOPT_INVERT},
+ { .name = "srh-lsid", .id = O_SRH_LSID, .type = XTTYPE_HOSTMASK,
+ .flags = XTOPT_INVERT},
{ }
};
#undef s
@@ -75,6 +87,12 @@ static void srh_init(struct xt_entry_match *m)

srhinfo->mt_flags = 0;
srhinfo->mt_invflags = 0;
+ memset(srhinfo->psid_addr.s6_addr, 0, sizeof(srhinfo->psid_addr.s6_addr));
+ memset(srhinfo->nsid_addr.s6_addr, 0, sizeof(srhinfo->nsid_addr.s6_addr));
+ memset(srhinfo->lsid_addr.s6_addr, 0, sizeof(srhinfo->lsid_addr.s6_addr));
+ memset(srhinfo->psid_msk.s6_addr, 0, sizeof(srhinfo->psid_msk.s6_addr));
+ memset(srhinfo->nsid_msk.s6_addr, 0, sizeof(srhinfo->nsid_msk.s6_addr));
+ memset(srhinfo->lsid_msk.s6_addr, 0, sizeof(srhinfo->lsid_msk.s6_addr));
}

static void srh_parse(struct xt_option_call *cb)
@@ -138,6 +156,27 @@ static void srh_parse(struct xt_option_call *cb)
if (cb->invert)
srhinfo->mt_invflags |= IP6T_SRH_INV_TAG;
break;
+ case O_SRH_PSID:
+ srhinfo->mt_flags |= IP6T_SRH_PSID;
+ srhinfo->psid_addr = cb->val.haddr.in6;
+ srhinfo->psid_msk = cb->val.hmask.in6;
+ if (cb->invert)
+ srhinfo->mt_invflags |= IP6T_SRH_INV_PSID;
+ break;
+ case O_SRH_NSID:
+ srhinfo->mt_flags |= IP6T_SRH_NSID;
+ srhinfo->nsid_addr = cb->val.haddr.in6;
+ srhinfo->nsid_msk = cb->val.hmask.in6;
+ if (cb->invert)
+ srhinfo->mt_invflags |= IP6T_SRH_INV_NSID;
+ break;
+ case O_SRH_LSID:
+ srhinfo->mt_flags |= IP6T_SRH_LSID;
+ srhinfo->lsid_addr = cb->val.haddr.in6;
+ srhinfo->lsid_msk = cb->val.hmask.in6;
+ if (cb->invert)
+ srhinfo->mt_invflags |= IP6T_SRH_INV_LSID;
+ break;
}
}

@@ -180,6 +219,18 @@ static void srh_print(const void *ip, const struct xt_entry_match *match,
if (srhinfo->mt_flags & IP6T_SRH_TAG)
printf(" tag:%s%d", srhinfo->mt_invflags & IP6T_SRH_INV_TAG ? "!" : "",
srhinfo->tag);
+ if (srhinfo->mt_flags & IP6T_SRH_PSID)
+ printf(" psid %s %s/%u", srhinfo->mt_invflags & IP6T_SRH_INV_PSID ? "!" : "",
+ xtables_ip6addr_to_numeric(&srhinfo->psid_addr),
+ xtables_ip6mask_to_cidr(&srhinfo->psid_msk));
+ if (srhinfo->mt_flags & IP6T_SRH_NSID)
+ printf(" nsid %s %s/%u", srhinfo->mt_invflags & IP6T_SRH_INV_NSID ? "!" : "",
+ xtables_ip6addr_to_numeric(&srhinfo->nsid_addr),
+ xtables_ip6mask_to_cidr(&srhinfo->nsid_msk));
+ if (srhinfo->mt_flags & IP6T_SRH_LSID)
+ printf(" lsid %s %s/%u", srhinfo->mt_invflags & IP6T_SRH_INV_LSID ? "!" : "",
+ xtables_ip6addr_to_numeric(&srhinfo->lsid_addr),
+ xtables_ip6mask_to_cidr(&srhinfo->lsid_msk));
}

static void srh_save(const void *ip, const struct xt_entry_match *match)
@@ -219,6 +270,18 @@ static void srh_save(const void *ip, const struct xt_entry_match *match)
if (srhinfo->mt_flags & IP6T_SRH_TAG)
printf("%s --srh-tag %u", (srhinfo->mt_invflags & IP6T_SRH_INV_TAG) ? " !" : "",
srhinfo->tag);
+ if (srhinfo->mt_flags & IP6T_SRH_PSID)
+ printf("%s --srh-psid %s/%u", srhinfo->mt_invflags & IP6T_SRH_INV_PSID ? " !" : "",
+ xtables_ip6addr_to_numeric(&srhinfo->psid_addr),
+ xtables_ip6mask_to_cidr(&srhinfo->psid_msk));
+ if (srhinfo->mt_flags & IP6T_SRH_NSID)
+ printf("%s --srh-nsid %s/%u", srhinfo->mt_invflags & IP6T_SRH_INV_NSID ? " !" : "",
+ xtables_ip6addr_to_numeric(&srhinfo->nsid_addr),
+ xtables_ip6mask_to_cidr(&srhinfo->nsid_msk));
+ if (srhinfo->mt_flags & IP6T_SRH_LSID)
+ printf("%s --srh-lsid %s/%u", srhinfo->mt_invflags & IP6T_SRH_INV_LSID ? " !" : "",
+ xtables_ip6addr_to_numeric(&srhinfo->lsid_addr),
+ xtables_ip6mask_to_cidr(&srhinfo->lsid_msk));
}

static struct xtables_match srh_mt6_reg = {
diff --git a/include/linux/netfilter_ipv6/ip6t_srh.h b/include/linux/netfilter_ipv6/ip6t_srh.h
index 087efa1..3d77241 100644
--- a/include/linux/netfilter_ipv6/ip6t_srh.h
+++ b/include/linux/netfilter_ipv6/ip6t_srh.h
@@ -16,7 +16,10 @@
#define IP6T_SRH_LAST_GT 0x0100
#define IP6T_SRH_LAST_LT 0x0200
#define IP6T_SRH_TAG 0x0400
-#define IP6T_SRH_MASK 0x07FF
+#define IP6T_SRH_PSID 0x0800
+#define IP6T_SRH_NSID 0x1000
+#define IP6T_SRH_LSID 0x2000
+#define IP6T_SRH_MASK 0x3FFF

/* Values for "mt_invflags" field in struct ip6t_srh */
#define IP6T_SRH_INV_NEXTHDR 0x0001
@@ -30,7 +33,10 @@
#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
+#define IP6T_SRH_INV_PSID 0x0800
+#define IP6T_SRH_INV_NSID 0x1000
+#define IP6T_SRH_INV_LSID 0x2000
+#define IP6T_SRH_INV_MASK 0x3FFF

/**
* struct ip6t_srh - SRH match options
@@ -39,6 +45,12 @@
* @ segs_left: Segments left field of SRH
* @ last_entry: Last entry field of SRH
* @ tag: Tag field of SRH
+ * @ psid_addr: Address of previous SID in SRH SID list
+ * @ nsid_addr: Address of NEXT SID in SRH SID list
+ * @ lsid_addr: Address of LAST SID in SRH SID list
+ * @ psid_msk: Mask of previous SID in SRH SID list
+ * @ nsid_msk: Mask of next SID in SRH SID list
+ * @ lsid_msk: MAsk of last SID in SRH SID list
* @ mt_flags: match options
* @ mt_invflags: Invert the sense of match options
*/
@@ -49,6 +61,12 @@ struct ip6t_srh {
__u8 segs_left;
__u8 last_entry;
__u16 tag;
+ struct in6_addr psid_addr;
+ struct in6_addr nsid_addr;
+ struct in6_addr lsid_addr;
+ struct in6_addr psid_msk;
+ struct in6_addr nsid_msk;
+ struct in6_addr lsid_msk;
__u16 mt_flags;
__u16 mt_invflags;
};
--
2.1.4