From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- net/ipv6/seg6.c | 569 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 569 insertions(+) create mode 100644 net/ipv6/seg6.c (limited to 'net/ipv6/seg6.c') diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c new file mode 100644 index 000000000..29346a6ee --- /dev/null +++ b/net/ipv6/seg6.c @@ -0,0 +1,569 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * SR-IPv6 implementation + * + * Author: + * David Lebrun + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include +#include +#include +#include +#ifdef CONFIG_IPV6_SEG6_HMAC +#include +#endif + +bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len, bool reduced) +{ + unsigned int tlv_offset; + int max_last_entry; + int trailing; + + if (srh->type != IPV6_SRCRT_TYPE_4) + return false; + + if (((srh->hdrlen + 1) << 3) != len) + return false; + + if (!reduced && srh->segments_left > srh->first_segment) { + return false; + } else { + max_last_entry = (srh->hdrlen / 2) - 1; + + if (srh->first_segment > max_last_entry) + return false; + + if (srh->segments_left > srh->first_segment + 1) + return false; + } + + tlv_offset = sizeof(*srh) + ((srh->first_segment + 1) << 4); + + trailing = len - tlv_offset; + if (trailing < 0) + return false; + + while (trailing) { + struct sr6_tlv *tlv; + unsigned int tlv_len; + + if (trailing < sizeof(*tlv)) + return false; + + tlv = (struct sr6_tlv *)((unsigned char *)srh + tlv_offset); + tlv_len = sizeof(*tlv) + tlv->len; + + trailing -= tlv_len; + if (trailing < 0) + return false; + + tlv_offset += tlv_len; + } + + return true; +} + +struct ipv6_sr_hdr *seg6_get_srh(struct sk_buff *skb, int flags) +{ + struct ipv6_sr_hdr *srh; + int len, srhoff = 0; + + if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, &flags) < 0) + return NULL; + + if (!pskb_may_pull(skb, srhoff + sizeof(*srh))) + return NULL; + + srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); + + len = (srh->hdrlen + 1) << 3; + + if (!pskb_may_pull(skb, srhoff + len)) + return NULL; + + /* note that pskb_may_pull may change pointers in header; + * for this reason it is necessary to reload them when needed. + */ + srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); + + if (!seg6_validate_srh(srh, len, true)) + return NULL; + + return srh; +} + +/* Determine if an ICMP invoking packet contains a segment routing + * header. If it does, extract the offset to the true destination + * address, which is in the first segment address. + */ +void seg6_icmp_srh(struct sk_buff *skb, struct inet6_skb_parm *opt) +{ + __u16 network_header = skb->network_header; + struct ipv6_sr_hdr *srh; + + /* Update network header to point to the invoking packet + * inside the ICMP packet, so we can use the seg6_get_srh() + * helper. + */ + skb_reset_network_header(skb); + + srh = seg6_get_srh(skb, 0); + if (!srh) + goto out; + + if (srh->type != IPV6_SRCRT_TYPE_4) + goto out; + + opt->flags |= IP6SKB_SEG6; + opt->srhoff = (unsigned char *)srh - skb->data; + +out: + /* Restore the network header back to the ICMP packet */ + skb->network_header = network_header; +} + +static struct genl_family seg6_genl_family; + +static const struct nla_policy seg6_genl_policy[SEG6_ATTR_MAX + 1] = { + [SEG6_ATTR_DST] = { .type = NLA_BINARY, + .len = sizeof(struct in6_addr) }, + [SEG6_ATTR_DSTLEN] = { .type = NLA_S32, }, + [SEG6_ATTR_HMACKEYID] = { .type = NLA_U32, }, + [SEG6_ATTR_SECRET] = { .type = NLA_BINARY, }, + [SEG6_ATTR_SECRETLEN] = { .type = NLA_U8, }, + [SEG6_ATTR_ALGID] = { .type = NLA_U8, }, + [SEG6_ATTR_HMACINFO] = { .type = NLA_NESTED, }, +}; + +#ifdef CONFIG_IPV6_SEG6_HMAC + +static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info) +{ + struct net *net = genl_info_net(info); + struct seg6_pernet_data *sdata; + struct seg6_hmac_info *hinfo; + u32 hmackeyid; + char *secret; + int err = 0; + u8 algid; + u8 slen; + + sdata = seg6_pernet(net); + + if (!info->attrs[SEG6_ATTR_HMACKEYID] || + !info->attrs[SEG6_ATTR_SECRETLEN] || + !info->attrs[SEG6_ATTR_ALGID]) + return -EINVAL; + + hmackeyid = nla_get_u32(info->attrs[SEG6_ATTR_HMACKEYID]); + slen = nla_get_u8(info->attrs[SEG6_ATTR_SECRETLEN]); + algid = nla_get_u8(info->attrs[SEG6_ATTR_ALGID]); + + if (hmackeyid == 0) + return -EINVAL; + + if (slen > SEG6_HMAC_SECRET_LEN) + return -EINVAL; + + mutex_lock(&sdata->lock); + hinfo = seg6_hmac_info_lookup(net, hmackeyid); + + if (!slen) { + err = seg6_hmac_info_del(net, hmackeyid); + + goto out_unlock; + } + + if (!info->attrs[SEG6_ATTR_SECRET]) { + err = -EINVAL; + goto out_unlock; + } + + if (slen > nla_len(info->attrs[SEG6_ATTR_SECRET])) { + err = -EINVAL; + goto out_unlock; + } + + if (hinfo) { + err = seg6_hmac_info_del(net, hmackeyid); + if (err) + goto out_unlock; + } + + secret = (char *)nla_data(info->attrs[SEG6_ATTR_SECRET]); + + hinfo = kzalloc(sizeof(*hinfo), GFP_KERNEL); + if (!hinfo) { + err = -ENOMEM; + goto out_unlock; + } + + memcpy(hinfo->secret, secret, slen); + hinfo->slen = slen; + hinfo->alg_id = algid; + hinfo->hmackeyid = hmackeyid; + + err = seg6_hmac_info_add(net, hmackeyid, hinfo); + if (err) + kfree(hinfo); + +out_unlock: + mutex_unlock(&sdata->lock); + return err; +} + +#else + +static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info) +{ + return -ENOTSUPP; +} + +#endif + +static int seg6_genl_set_tunsrc(struct sk_buff *skb, struct genl_info *info) +{ + struct net *net = genl_info_net(info); + struct in6_addr *val, *t_old, *t_new; + struct seg6_pernet_data *sdata; + + sdata = seg6_pernet(net); + + if (!info->attrs[SEG6_ATTR_DST]) + return -EINVAL; + + val = nla_data(info->attrs[SEG6_ATTR_DST]); + t_new = kmemdup(val, sizeof(*val), GFP_KERNEL); + if (!t_new) + return -ENOMEM; + + mutex_lock(&sdata->lock); + + t_old = sdata->tun_src; + rcu_assign_pointer(sdata->tun_src, t_new); + + mutex_unlock(&sdata->lock); + + synchronize_net(); + kfree(t_old); + + return 0; +} + +static int seg6_genl_get_tunsrc(struct sk_buff *skb, struct genl_info *info) +{ + struct net *net = genl_info_net(info); + struct in6_addr *tun_src; + struct sk_buff *msg; + void *hdr; + + msg = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq, + &seg6_genl_family, 0, SEG6_CMD_GET_TUNSRC); + if (!hdr) + goto free_msg; + + rcu_read_lock(); + tun_src = rcu_dereference(seg6_pernet(net)->tun_src); + + if (nla_put(msg, SEG6_ATTR_DST, sizeof(struct in6_addr), tun_src)) + goto nla_put_failure; + + rcu_read_unlock(); + + genlmsg_end(msg, hdr); + return genlmsg_reply(msg, info); + +nla_put_failure: + rcu_read_unlock(); +free_msg: + nlmsg_free(msg); + return -ENOMEM; +} + +#ifdef CONFIG_IPV6_SEG6_HMAC + +static int __seg6_hmac_fill_info(struct seg6_hmac_info *hinfo, + struct sk_buff *msg) +{ + if (nla_put_u32(msg, SEG6_ATTR_HMACKEYID, hinfo->hmackeyid) || + nla_put_u8(msg, SEG6_ATTR_SECRETLEN, hinfo->slen) || + nla_put(msg, SEG6_ATTR_SECRET, hinfo->slen, hinfo->secret) || + nla_put_u8(msg, SEG6_ATTR_ALGID, hinfo->alg_id)) + return -1; + + return 0; +} + +static int __seg6_genl_dumphmac_element(struct seg6_hmac_info *hinfo, + u32 portid, u32 seq, u32 flags, + struct sk_buff *skb, u8 cmd) +{ + void *hdr; + + hdr = genlmsg_put(skb, portid, seq, &seg6_genl_family, flags, cmd); + if (!hdr) + return -ENOMEM; + + if (__seg6_hmac_fill_info(hinfo, skb) < 0) + goto nla_put_failure; + + genlmsg_end(skb, hdr); + return 0; + +nla_put_failure: + genlmsg_cancel(skb, hdr); + return -EMSGSIZE; +} + +static int seg6_genl_dumphmac_start(struct netlink_callback *cb) +{ + struct net *net = sock_net(cb->skb->sk); + struct seg6_pernet_data *sdata; + struct rhashtable_iter *iter; + + sdata = seg6_pernet(net); + iter = (struct rhashtable_iter *)cb->args[0]; + + if (!iter) { + iter = kmalloc(sizeof(*iter), GFP_KERNEL); + if (!iter) + return -ENOMEM; + + cb->args[0] = (long)iter; + } + + rhashtable_walk_enter(&sdata->hmac_infos, iter); + + return 0; +} + +static int seg6_genl_dumphmac_done(struct netlink_callback *cb) +{ + struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0]; + + rhashtable_walk_exit(iter); + + kfree(iter); + + return 0; +} + +static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb) +{ + struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0]; + struct seg6_hmac_info *hinfo; + int ret; + + rhashtable_walk_start(iter); + + for (;;) { + hinfo = rhashtable_walk_next(iter); + + if (IS_ERR(hinfo)) { + if (PTR_ERR(hinfo) == -EAGAIN) + continue; + ret = PTR_ERR(hinfo); + goto done; + } else if (!hinfo) { + break; + } + + ret = __seg6_genl_dumphmac_element(hinfo, + NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, + NLM_F_MULTI, + skb, SEG6_CMD_DUMPHMAC); + if (ret) + goto done; + } + + ret = skb->len; + +done: + rhashtable_walk_stop(iter); + return ret; +} + +#else + +static int seg6_genl_dumphmac_start(struct netlink_callback *cb) +{ + return 0; +} + +static int seg6_genl_dumphmac_done(struct netlink_callback *cb) +{ + return 0; +} + +static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb) +{ + return -ENOTSUPP; +} + +#endif + +static int __net_init seg6_net_init(struct net *net) +{ + struct seg6_pernet_data *sdata; + + sdata = kzalloc(sizeof(*sdata), GFP_KERNEL); + if (!sdata) + return -ENOMEM; + + mutex_init(&sdata->lock); + + sdata->tun_src = kzalloc(sizeof(*sdata->tun_src), GFP_KERNEL); + if (!sdata->tun_src) { + kfree(sdata); + return -ENOMEM; + } + + net->ipv6.seg6_data = sdata; + +#ifdef CONFIG_IPV6_SEG6_HMAC + if (seg6_hmac_net_init(net)) { + kfree(rcu_dereference_raw(sdata->tun_src)); + kfree(sdata); + return -ENOMEM; + } +#endif + + return 0; +} + +static void __net_exit seg6_net_exit(struct net *net) +{ + struct seg6_pernet_data *sdata = seg6_pernet(net); + +#ifdef CONFIG_IPV6_SEG6_HMAC + seg6_hmac_net_exit(net); +#endif + + kfree(rcu_dereference_raw(sdata->tun_src)); + kfree(sdata); +} + +static struct pernet_operations ip6_segments_ops = { + .init = seg6_net_init, + .exit = seg6_net_exit, +}; + +static const struct genl_ops seg6_genl_ops[] = { + { + .cmd = SEG6_CMD_SETHMAC, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = seg6_genl_sethmac, + .flags = GENL_ADMIN_PERM, + }, + { + .cmd = SEG6_CMD_DUMPHMAC, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .start = seg6_genl_dumphmac_start, + .dumpit = seg6_genl_dumphmac, + .done = seg6_genl_dumphmac_done, + .flags = GENL_ADMIN_PERM, + }, + { + .cmd = SEG6_CMD_SET_TUNSRC, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = seg6_genl_set_tunsrc, + .flags = GENL_ADMIN_PERM, + }, + { + .cmd = SEG6_CMD_GET_TUNSRC, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = seg6_genl_get_tunsrc, + .flags = GENL_ADMIN_PERM, + }, +}; + +static struct genl_family seg6_genl_family __ro_after_init = { + .hdrsize = 0, + .name = SEG6_GENL_NAME, + .version = SEG6_GENL_VERSION, + .maxattr = SEG6_ATTR_MAX, + .policy = seg6_genl_policy, + .netnsok = true, + .parallel_ops = true, + .ops = seg6_genl_ops, + .n_ops = ARRAY_SIZE(seg6_genl_ops), + .resv_start_op = SEG6_CMD_GET_TUNSRC + 1, + .module = THIS_MODULE, +}; + +int __init seg6_init(void) +{ + int err; + + err = genl_register_family(&seg6_genl_family); + if (err) + goto out; + + err = register_pernet_subsys(&ip6_segments_ops); + if (err) + goto out_unregister_genl; + +#ifdef CONFIG_IPV6_SEG6_LWTUNNEL + err = seg6_iptunnel_init(); + if (err) + goto out_unregister_pernet; + + err = seg6_local_init(); + if (err) + goto out_unregister_pernet; +#endif + +#ifdef CONFIG_IPV6_SEG6_HMAC + err = seg6_hmac_init(); + if (err) + goto out_unregister_iptun; +#endif + + pr_info("Segment Routing with IPv6\n"); + +out: + return err; +#ifdef CONFIG_IPV6_SEG6_HMAC +out_unregister_iptun: +#ifdef CONFIG_IPV6_SEG6_LWTUNNEL + seg6_local_exit(); + seg6_iptunnel_exit(); +#endif +#endif +#ifdef CONFIG_IPV6_SEG6_LWTUNNEL +out_unregister_pernet: + unregister_pernet_subsys(&ip6_segments_ops); +#endif +out_unregister_genl: + genl_unregister_family(&seg6_genl_family); + goto out; +} + +void seg6_exit(void) +{ +#ifdef CONFIG_IPV6_SEG6_HMAC + seg6_hmac_exit(); +#endif +#ifdef CONFIG_IPV6_SEG6_LWTUNNEL + seg6_iptunnel_exit(); +#endif + unregister_pernet_subsys(&ip6_segments_ops); + genl_unregister_family(&seg6_genl_family); +} -- cgit v1.2.3