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authorAlexander Aring <alex.aring@gmail.com>2020-03-27 18:00:20 -0400
committerDavid S. Miller <davem@davemloft.net>2020-03-29 22:30:57 -0700
commit8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 (patch)
tree638528cb15fa478b0532b882f76a8212acfb2e66 /net
parentf37c6059363403d528acf8d530bb6e8a5666a875 (diff)
net: ipv6: add support for rpl sr exthdr
This patch adds rpl source routing receive handling. Everything works only if sysconf "rpl_seg_enabled" and source routing is enabled. Mostly the same behaviour as IPv6 segmentation routing. To handle compression and uncompression a rpl.c file is created which contains the necessary functionality. The receive handling will also care about IPv6 encapsulated so far it's specified as possible nexthdr in RFC 6554. Signed-off-by: Alexander Aring <alex.aring@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv6/Makefile2
-rw-r--r--net/ipv6/addrconf.c10
-rw-r--r--net/ipv6/exthdrs.c201
-rw-r--r--net/ipv6/rpl.c123
4 files changed, 333 insertions, 3 deletions
diff --git a/net/ipv6/Makefile b/net/ipv6/Makefile
index 8ccf35514015..9d3e9bd2334f 100644
--- a/net/ipv6/Makefile
+++ b/net/ipv6/Makefile
@@ -10,7 +10,7 @@ ipv6-objs := af_inet6.o anycast.o ip6_output.o ip6_input.o addrconf.o \
route.o ip6_fib.o ipv6_sockglue.o ndisc.o udp.o udplite.o \
raw.o icmp.o mcast.o reassembly.o tcp_ipv6.o ping.o \
exthdrs.o datagram.o ip6_flowlabel.o inet6_connection_sock.o \
- udp_offload.o seg6.o fib6_notifier.o
+ udp_offload.o seg6.o fib6_notifier.o rpl.o
ipv6-offload := ip6_offload.o tcpv6_offload.o exthdrs_offload.o
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 594963a7e1ec..a11fd4d67832 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -236,6 +236,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = {
.enhanced_dad = 1,
.addr_gen_mode = IN6_ADDR_GEN_MODE_EUI64,
.disable_policy = 0,
+ .rpl_seg_enabled = 0,
};
static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
@@ -290,6 +291,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
.enhanced_dad = 1,
.addr_gen_mode = IN6_ADDR_GEN_MODE_EUI64,
.disable_policy = 0,
+ .rpl_seg_enabled = 0,
};
/* Check if link is ready: is it up and is a valid qdisc available */
@@ -5520,6 +5522,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
array[DEVCONF_ADDR_GEN_MODE] = cnf->addr_gen_mode;
array[DEVCONF_DISABLE_POLICY] = cnf->disable_policy;
array[DEVCONF_NDISC_TCLASS] = cnf->ndisc_tclass;
+ array[DEVCONF_RPL_SEG_ENABLED] = cnf->rpl_seg_enabled;
}
static inline size_t inet6_ifla6_size(void)
@@ -6901,6 +6904,13 @@ static const struct ctl_table addrconf_sysctl[] = {
.extra2 = (void *)&two_five_five,
},
{
+ .procname = "rpl_seg_enabled",
+ .data = &ipv6_devconf.rpl_seg_enabled,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
/* sentinel */
}
};
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index bcb9f5e62808..5a8bbcdcaf2b 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -48,6 +48,7 @@
#ifdef CONFIG_IPV6_SEG6_HMAC
#include <net/seg6_hmac.h>
#endif
+#include <net/rpl.h>
#include <linux/uaccess.h>
@@ -468,6 +469,195 @@ looped_back:
return -1;
}
+static int ipv6_rpl_srh_rcv(struct sk_buff *skb)
+{
+ struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr;
+ struct inet6_skb_parm *opt = IP6CB(skb);
+ struct net *net = dev_net(skb->dev);
+ struct inet6_dev *idev;
+ struct ipv6hdr *oldhdr;
+ struct in6_addr addr;
+ unsigned char *buf;
+ int accept_rpl_seg;
+ int i, err;
+ u64 n = 0;
+ u32 r;
+
+ idev = __in6_dev_get(skb->dev);
+
+ accept_rpl_seg = net->ipv6.devconf_all->rpl_seg_enabled;
+ if (accept_rpl_seg > idev->cnf.rpl_seg_enabled)
+ accept_rpl_seg = idev->cnf.rpl_seg_enabled;
+
+ if (!accept_rpl_seg) {
+ kfree_skb(skb);
+ return -1;
+ }
+
+looped_back:
+ hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb);
+
+ if (hdr->segments_left == 0) {
+ if (hdr->nexthdr == NEXTHDR_IPV6) {
+ int offset = (hdr->hdrlen + 1) << 3;
+
+ skb_postpull_rcsum(skb, skb_network_header(skb),
+ skb_network_header_len(skb));
+
+ if (!pskb_pull(skb, offset)) {
+ kfree_skb(skb);
+ return -1;
+ }
+ skb_postpull_rcsum(skb, skb_transport_header(skb),
+ offset);
+
+ skb_reset_network_header(skb);
+ skb_reset_transport_header(skb);
+ skb->encapsulation = 0;
+
+ __skb_tunnel_rx(skb, skb->dev, net);
+
+ netif_rx(skb);
+ return -1;
+ }
+
+ opt->srcrt = skb_network_header_len(skb);
+ opt->lastopt = opt->srcrt;
+ skb->transport_header += (hdr->hdrlen + 1) << 3;
+ opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
+
+ return 1;
+ }
+
+ if (!pskb_may_pull(skb, sizeof(*hdr))) {
+ kfree_skb(skb);
+ return -1;
+ }
+
+ n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre);
+ r = do_div(n, (16 - hdr->cmpri));
+ /* checks if calculation was without remainder and n fits into
+ * unsigned char which is segments_left field. Should not be
+ * higher than that.
+ */
+ if (r || (n + 1) > 255) {
+ kfree_skb(skb);
+ return -1;
+ }
+
+ if (hdr->segments_left > n + 1) {
+ __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
+ icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
+ ((&hdr->segments_left) -
+ skb_network_header(skb)));
+ return -1;
+ }
+
+ if (skb_cloned(skb)) {
+ if (pskb_expand_head(skb, IPV6_RPL_SRH_WORST_SWAP_SIZE, 0,
+ GFP_ATOMIC)) {
+ __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+ IPSTATS_MIB_OUTDISCARDS);
+ kfree_skb(skb);
+ return -1;
+ }
+ } else {
+ err = skb_cow_head(skb, IPV6_RPL_SRH_WORST_SWAP_SIZE);
+ if (unlikely(err)) {
+ kfree_skb(skb);
+ return -1;
+ }
+ }
+
+ hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb);
+
+ if (!pskb_may_pull(skb, ipv6_rpl_srh_size(n, hdr->cmpri,
+ hdr->cmpre))) {
+ kfree_skb(skb);
+ return -1;
+ }
+
+ hdr->segments_left--;
+ i = n - hdr->segments_left;
+
+ buf = kzalloc(ipv6_rpl_srh_alloc_size(n + 1) * 2, GFP_ATOMIC);
+ if (unlikely(!buf)) {
+ kfree_skb(skb);
+ return -1;
+ }
+
+ ohdr = (struct ipv6_rpl_sr_hdr *)buf;
+ ipv6_rpl_srh_decompress(ohdr, hdr, &ipv6_hdr(skb)->daddr, n);
+ chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3));
+
+ if ((ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST) ||
+ (ipv6_addr_type(&ohdr->rpl_segaddr[i]) & IPV6_ADDR_MULTICAST)) {
+ kfree_skb(skb);
+ kfree(buf);
+ return -1;
+ }
+
+ err = ipv6_chk_rpl_srh_loop(net, ohdr->rpl_segaddr, n + 1);
+ if (err) {
+ icmpv6_send(skb, ICMPV6_PARAMPROB, 0, 0);
+ kfree_skb(skb);
+ kfree(buf);
+ return -1;
+ }
+
+ addr = ipv6_hdr(skb)->daddr;
+ ipv6_hdr(skb)->daddr = ohdr->rpl_segaddr[i];
+ ohdr->rpl_segaddr[i] = addr;
+
+ ipv6_rpl_srh_compress(chdr, ohdr, &ipv6_hdr(skb)->daddr, n);
+
+ oldhdr = ipv6_hdr(skb);
+
+ skb_pull(skb, ((hdr->hdrlen + 1) << 3));
+ skb_postpull_rcsum(skb, oldhdr,
+ sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3));
+ skb_push(skb, ((chdr->hdrlen + 1) << 3) + sizeof(struct ipv6hdr));
+ skb_reset_network_header(skb);
+ skb_mac_header_rebuild(skb);
+ skb_set_transport_header(skb, sizeof(struct ipv6hdr));
+
+ memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr));
+ memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3);
+
+ ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
+ skb_postpush_rcsum(skb, ipv6_hdr(skb),
+ sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3));
+
+ kfree(buf);
+
+ skb_dst_drop(skb);
+
+ ip6_route_input(skb);
+
+ if (skb_dst(skb)->error) {
+ dst_input(skb);
+ return -1;
+ }
+
+ if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
+ if (ipv6_hdr(skb)->hop_limit <= 1) {
+ __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
+ icmpv6_send(skb, ICMPV6_TIME_EXCEED,
+ ICMPV6_EXC_HOPLIMIT, 0);
+ kfree_skb(skb);
+ return -1;
+ }
+ ipv6_hdr(skb)->hop_limit--;
+
+ skb_pull(skb, sizeof(struct ipv6hdr));
+ goto looped_back;
+ }
+
+ dst_input(skb);
+
+ return -1;
+}
+
/********************************
Routing header.
********************************/
@@ -506,9 +696,16 @@ static int ipv6_rthdr_rcv(struct sk_buff *skb)
return -1;
}
- /* segment routing */
- if (hdr->type == IPV6_SRCRT_TYPE_4)
+ switch (hdr->type) {
+ case IPV6_SRCRT_TYPE_4:
+ /* segment routing */
return ipv6_srh_rcv(skb);
+ case IPV6_SRCRT_TYPE_3:
+ /* rpl segment routing */
+ return ipv6_rpl_srh_rcv(skb);
+ default:
+ break;
+ }
looped_back:
if (hdr->segments_left == 0) {
diff --git a/net/ipv6/rpl.c b/net/ipv6/rpl.c
new file mode 100644
index 000000000000..dc4f20e23bf7
--- /dev/null
+++ b/net/ipv6/rpl.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/**
+ * Authors:
+ * (C) 2020 Alexander Aring <alex.aring@gmail.com>
+ */
+
+#include <net/ipv6.h>
+#include <net/rpl.h>
+
+#define IPV6_PFXTAIL_LEN(x) (sizeof(struct in6_addr) - (x))
+
+static void ipv6_rpl_addr_decompress(struct in6_addr *dst,
+ const struct in6_addr *daddr,
+ const void *post, unsigned char pfx)
+{
+ memcpy(dst, daddr, pfx);
+ memcpy(&dst->s6_addr[pfx], post, IPV6_PFXTAIL_LEN(pfx));
+}
+
+static void ipv6_rpl_addr_compress(void *dst, const struct in6_addr *addr,
+ unsigned char pfx)
+{
+ memcpy(dst, &addr->s6_addr[pfx], IPV6_PFXTAIL_LEN(pfx));
+}
+
+static void *ipv6_rpl_segdata_pos(const struct ipv6_rpl_sr_hdr *hdr, int i)
+{
+ return (void *)&hdr->rpl_segdata[i * IPV6_PFXTAIL_LEN(hdr->cmpri)];
+}
+
+size_t ipv6_rpl_srh_size(unsigned char n, unsigned char cmpri,
+ unsigned char cmpre)
+{
+ return (n * IPV6_PFXTAIL_LEN(cmpri)) + IPV6_PFXTAIL_LEN(cmpre);
+}
+
+void ipv6_rpl_srh_decompress(struct ipv6_rpl_sr_hdr *outhdr,
+ const struct ipv6_rpl_sr_hdr *inhdr,
+ const struct in6_addr *daddr, unsigned char n)
+{
+ int i;
+
+ outhdr->nexthdr = inhdr->nexthdr;
+ outhdr->hdrlen = (((n + 1) * sizeof(struct in6_addr)) >> 3);
+ outhdr->pad = 0;
+ outhdr->type = inhdr->type;
+ outhdr->segments_left = inhdr->segments_left;
+ outhdr->cmpri = 0;
+ outhdr->cmpre = 0;
+
+ for (i = 0; i <= n; i++)
+ ipv6_rpl_addr_decompress(&outhdr->rpl_segaddr[i], daddr,
+ ipv6_rpl_segdata_pos(inhdr, i),
+ inhdr->cmpri);
+
+ ipv6_rpl_addr_decompress(&outhdr->rpl_segaddr[n], daddr,
+ ipv6_rpl_segdata_pos(inhdr, n),
+ inhdr->cmpre);
+}
+
+static unsigned char ipv6_rpl_srh_calc_cmpri(const struct ipv6_rpl_sr_hdr *inhdr,
+ const struct in6_addr *daddr,
+ unsigned char n)
+{
+ unsigned char plen;
+ int i;
+
+ for (plen = 0; plen < sizeof(*daddr); plen++) {
+ for (i = 0; i <= n; i++) {
+ if (daddr->s6_addr[plen] !=
+ inhdr->rpl_segaddr[i].s6_addr[plen])
+ return plen;
+ }
+ }
+
+ return plen;
+}
+
+static unsigned char ipv6_rpl_srh_calc_cmpre(const struct in6_addr *daddr,
+ const struct in6_addr *last_segment)
+{
+ unsigned int plen;
+
+ for (plen = 0; plen < sizeof(*daddr); plen++) {
+ if (daddr->s6_addr[plen] != last_segment->s6_addr[plen])
+ break;
+ }
+
+ return plen;
+}
+
+void ipv6_rpl_srh_compress(struct ipv6_rpl_sr_hdr *outhdr,
+ const struct ipv6_rpl_sr_hdr *inhdr,
+ const struct in6_addr *daddr, unsigned char n)
+{
+ unsigned char cmpri, cmpre;
+ size_t seglen;
+ int i;
+
+ cmpri = ipv6_rpl_srh_calc_cmpri(inhdr, daddr, n);
+ cmpre = ipv6_rpl_srh_calc_cmpre(daddr, &inhdr->rpl_segaddr[n]);
+
+ outhdr->nexthdr = inhdr->nexthdr;
+ seglen = (n * IPV6_PFXTAIL_LEN(cmpri)) + IPV6_PFXTAIL_LEN(cmpre);
+ outhdr->hdrlen = seglen >> 3;
+ if (seglen & 0x7) {
+ outhdr->hdrlen++;
+ outhdr->pad = 8 - (seglen & 0x7);
+ } else {
+ outhdr->pad = 0;
+ }
+ outhdr->type = inhdr->type;
+ outhdr->segments_left = inhdr->segments_left;
+ outhdr->cmpri = cmpri;
+ outhdr->cmpre = cmpre;
+
+ for (i = 0; i <= n; i++)
+ ipv6_rpl_addr_compress(ipv6_rpl_segdata_pos(outhdr, i),
+ &inhdr->rpl_segaddr[i], cmpri);
+
+ ipv6_rpl_addr_compress(ipv6_rpl_segdata_pos(outhdr, n),
+ &inhdr->rpl_segaddr[n], cmpre);
+}