diff options
Diffstat (limited to 'net/ipv6/exthdrs.c')
-rw-r--r-- | net/ipv6/exthdrs.c | 870 |
1 files changed, 870 insertions, 0 deletions
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c new file mode 100644 index 0000000..6bfffec --- /dev/null +++ b/net/ipv6/exthdrs.c @@ -0,0 +1,870 @@ +/* + * Extension Header handling for IPv6 + * Linux INET6 implementation + * + * Authors: + * Pedro Roque <roque@di.fc.ul.pt> + * Andi Kleen <ak@muc.de> + * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +/* Changes: + * yoshfuji : ensure not to overrun while parsing + * tlv options. + * Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs(). + * YOSHIFUJI Hideaki @USAGI Register inbound extension header + * handlers as inet6_protocol{}. + */ + +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/net.h> +#include <linux/netdevice.h> +#include <linux/in6.h> +#include <linux/icmpv6.h> + +#include <net/dst.h> +#include <net/sock.h> +#include <net/snmp.h> + +#include <net/ipv6.h> +#include <net/protocol.h> +#include <net/transp_v6.h> +#include <net/rawv6.h> +#include <net/ndisc.h> +#include <net/ip6_route.h> +#include <net/addrconf.h> +#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) +#include <net/xfrm.h> +#endif + +#include <asm/uaccess.h> + +int ipv6_find_tlv(struct sk_buff *skb, int offset, int type) +{ + const unsigned char *nh = skb_network_header(skb); + int packet_len = skb->tail - skb->network_header; + struct ipv6_opt_hdr *hdr; + int len; + + if (offset + 2 > packet_len) + goto bad; + hdr = (struct ipv6_opt_hdr *)(nh + offset); + len = ((hdr->hdrlen + 1) << 3); + + if (offset + len > packet_len) + goto bad; + + offset += 2; + len -= 2; + + while (len > 0) { + int opttype = nh[offset]; + int optlen; + + if (opttype == type) + return offset; + + switch (opttype) { + case IPV6_TLV_PAD0: + optlen = 1; + break; + default: + optlen = nh[offset + 1] + 2; + if (optlen > len) + goto bad; + break; + } + offset += optlen; + len -= optlen; + } + /* not_found */ + bad: + return -1; +} +EXPORT_SYMBOL_GPL(ipv6_find_tlv); + +/* + * Parsing tlv encoded headers. + * + * Parsing function "func" returns 1, if parsing succeed + * and 0, if it failed. + * It MUST NOT touch skb->h. + */ + +struct tlvtype_proc { + int type; + int (*func)(struct sk_buff *skb, int offset); +}; + +/********************* + Generic functions + *********************/ + +/* An unknown option is detected, decide what to do */ + +static int ip6_tlvopt_unknown(struct sk_buff *skb, int optoff) +{ + switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) { + case 0: /* ignore */ + return 1; + + case 1: /* drop packet */ + break; + + case 3: /* Send ICMP if not a multicast address and drop packet */ + /* Actually, it is redundant check. icmp_send + will recheck in any case. + */ + if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) + break; + case 2: /* send ICMP PARM PROB regardless and drop packet */ + icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff); + return 0; + } + + kfree_skb(skb); + return 0; +} + +/* Parse tlv encoded option header (hop-by-hop or destination) */ + +static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff *skb) +{ + struct tlvtype_proc *curr; + const unsigned char *nh = skb_network_header(skb); + int off = skb_network_header_len(skb); + int len = (skb_transport_header(skb)[1] + 1) << 3; + + if (skb_transport_offset(skb) + len > skb_headlen(skb)) + goto bad; + + off += 2; + len -= 2; + + while (len > 0) { + int optlen = nh[off + 1] + 2; + + switch (nh[off]) { + case IPV6_TLV_PAD0: + optlen = 1; + break; + + case IPV6_TLV_PADN: + break; + + default: /* Other TLV code so scan list */ + if (optlen > len) + goto bad; + for (curr=procs; curr->type >= 0; curr++) { + if (curr->type == nh[off]) { + /* type specific length/alignment + checks will be performed in the + func(). */ + if (curr->func(skb, off) == 0) + return 0; + break; + } + } + if (curr->type < 0) { + if (ip6_tlvopt_unknown(skb, off) == 0) + return 0; + } + break; + } + off += optlen; + len -= optlen; + } + if (len == 0) + return 1; +bad: + kfree_skb(skb); + return 0; +} + +/***************************** + Destination options header. + *****************************/ + +#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) +static int ipv6_dest_hao(struct sk_buff *skb, int optoff) +{ + struct ipv6_destopt_hao *hao; + struct inet6_skb_parm *opt = IP6CB(skb); + struct ipv6hdr *ipv6h = ipv6_hdr(skb); + struct in6_addr tmp_addr; + int ret; + + if (opt->dsthao) { + LIMIT_NETDEBUG(KERN_DEBUG "hao duplicated\n"); + goto discard; + } + opt->dsthao = opt->dst1; + opt->dst1 = 0; + + hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff); + + if (hao->length != 16) { + LIMIT_NETDEBUG( + KERN_DEBUG "hao invalid option length = %d\n", hao->length); + goto discard; + } + + if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) { + LIMIT_NETDEBUG( + KERN_DEBUG "hao is not an unicast addr: " NIP6_FMT "\n", NIP6(hao->addr)); + goto discard; + } + + ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr, + (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS); + if (unlikely(ret < 0)) + goto discard; + + if (skb_cloned(skb)) { + if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) + goto discard; + + /* update all variable using below by copied skbuff */ + hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + + optoff); + ipv6h = ipv6_hdr(skb); + } + + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->ip_summed = CHECKSUM_NONE; + + ipv6_addr_copy(&tmp_addr, &ipv6h->saddr); + ipv6_addr_copy(&ipv6h->saddr, &hao->addr); + ipv6_addr_copy(&hao->addr, &tmp_addr); + + if (skb->tstamp.tv64 == 0) + __net_timestamp(skb); + + return 1; + + discard: + kfree_skb(skb); + return 0; +} +#endif + +static struct tlvtype_proc tlvprocdestopt_lst[] = { +#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) + { + .type = IPV6_TLV_HAO, + .func = ipv6_dest_hao, + }, +#endif + {-1, NULL} +}; + +static int ipv6_destopt_rcv(struct sk_buff *skb) +{ + struct inet6_skb_parm *opt = IP6CB(skb); +#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) + __u16 dstbuf; +#endif + struct dst_entry *dst; + + if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || + !pskb_may_pull(skb, (skb_transport_offset(skb) + + ((skb_transport_header(skb)[1] + 1) << 3)))) { + IP6_INC_STATS_BH(dev_net(skb->dst->dev), ip6_dst_idev(skb->dst), + IPSTATS_MIB_INHDRERRORS); + kfree_skb(skb); + return -1; + } + + opt->lastopt = opt->dst1 = skb_network_header_len(skb); +#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) + dstbuf = opt->dst1; +#endif + + dst = dst_clone(skb->dst); + if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) { + dst_release(dst); + skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3; + opt = IP6CB(skb); +#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) + opt->nhoff = dstbuf; +#else + opt->nhoff = opt->dst1; +#endif + return 1; + } + + IP6_INC_STATS_BH(dev_net(dst->dev), + ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS); + dst_release(dst); + return -1; +} + +/******************************** + Routing header. + ********************************/ + +static int ipv6_rthdr_rcv(struct sk_buff *skb) +{ + struct inet6_skb_parm *opt = IP6CB(skb); + struct in6_addr *addr = NULL; + struct in6_addr daddr; + struct inet6_dev *idev; + int n, i; + struct ipv6_rt_hdr *hdr; + struct rt0_hdr *rthdr; + struct net *net = dev_net(skb->dev); + int accept_source_route = net->ipv6.devconf_all->accept_source_route; + + idev = in6_dev_get(skb->dev); + if (idev) { + if (accept_source_route > idev->cnf.accept_source_route) + accept_source_route = idev->cnf.accept_source_route; + in6_dev_put(idev); + } + + if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || + !pskb_may_pull(skb, (skb_transport_offset(skb) + + ((skb_transport_header(skb)[1] + 1) << 3)))) { + IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), + IPSTATS_MIB_INHDRERRORS); + kfree_skb(skb); + return -1; + } + + hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); + + if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) || + skb->pkt_type != PACKET_HOST) { + IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), + IPSTATS_MIB_INADDRERRORS); + kfree_skb(skb); + return -1; + } + +looped_back: + if (hdr->segments_left == 0) { + switch (hdr->type) { +#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) + case IPV6_SRCRT_TYPE_2: + /* Silently discard type 2 header unless it was + * processed by own + */ + if (!addr) { + IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), + IPSTATS_MIB_INADDRERRORS); + kfree_skb(skb); + return -1; + } + break; +#endif + default: + break; + } + + opt->lastopt = opt->srcrt = skb_network_header_len(skb); + skb->transport_header += (hdr->hdrlen + 1) << 3; + opt->dst0 = opt->dst1; + opt->dst1 = 0; + opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); + return 1; + } + + switch (hdr->type) { +#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) + case IPV6_SRCRT_TYPE_2: + if (accept_source_route < 0) + goto unknown_rh; + /* Silently discard invalid RTH type 2 */ + if (hdr->hdrlen != 2 || hdr->segments_left != 1) { + IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), + IPSTATS_MIB_INHDRERRORS); + kfree_skb(skb); + return -1; + } + break; +#endif + default: + goto unknown_rh; + } + + /* + * This is the routing header forwarding algorithm from + * RFC 2460, page 16. + */ + + n = hdr->hdrlen >> 1; + + if (hdr->segments_left > n) { + IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), + IPSTATS_MIB_INHDRERRORS); + icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, + ((&hdr->segments_left) - + skb_network_header(skb))); + return -1; + } + + /* We are about to mangle packet header. Be careful! + Do not damage packets queued somewhere. + */ + if (skb_cloned(skb)) { + /* the copy is a forwarded packet */ + if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { + IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), + IPSTATS_MIB_OUTDISCARDS); + kfree_skb(skb); + return -1; + } + hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); + } + + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->ip_summed = CHECKSUM_NONE; + + i = n - --hdr->segments_left; + + rthdr = (struct rt0_hdr *) hdr; + addr = rthdr->addr; + addr += i - 1; + + switch (hdr->type) { +#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) + case IPV6_SRCRT_TYPE_2: + if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, + (xfrm_address_t *)&ipv6_hdr(skb)->saddr, + IPPROTO_ROUTING) < 0) { + IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), + IPSTATS_MIB_INADDRERRORS); + kfree_skb(skb); + return -1; + } + if (!ipv6_chk_home_addr(dev_net(skb->dst->dev), addr)) { + IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), + IPSTATS_MIB_INADDRERRORS); + kfree_skb(skb); + return -1; + } + break; +#endif + default: + break; + } + + if (ipv6_addr_is_multicast(addr)) { + IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), + IPSTATS_MIB_INADDRERRORS); + kfree_skb(skb); + return -1; + } + + ipv6_addr_copy(&daddr, addr); + ipv6_addr_copy(addr, &ipv6_hdr(skb)->daddr); + ipv6_addr_copy(&ipv6_hdr(skb)->daddr, &daddr); + + dst_release(xchg(&skb->dst, NULL)); + ip6_route_input(skb); + if (skb->dst->error) { + skb_push(skb, skb->data - skb_network_header(skb)); + dst_input(skb); + return -1; + } + + if (skb->dst->dev->flags&IFF_LOOPBACK) { + if (ipv6_hdr(skb)->hop_limit <= 1) { + IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), + IPSTATS_MIB_INHDRERRORS); + icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, + 0, skb->dev); + kfree_skb(skb); + return -1; + } + ipv6_hdr(skb)->hop_limit--; + goto looped_back; + } + + skb_push(skb, skb->data - skb_network_header(skb)); + dst_input(skb); + return -1; + +unknown_rh: + IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS); + icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, + (&hdr->type) - skb_network_header(skb)); + return -1; +} + +static struct inet6_protocol rthdr_protocol = { + .handler = ipv6_rthdr_rcv, + .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, +}; + +static struct inet6_protocol destopt_protocol = { + .handler = ipv6_destopt_rcv, + .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, +}; + +static struct inet6_protocol nodata_protocol = { + .handler = dst_discard, + .flags = INET6_PROTO_NOPOLICY, +}; + +int __init ipv6_exthdrs_init(void) +{ + int ret; + + ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING); + if (ret) + goto out; + + ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS); + if (ret) + goto out_rthdr; + + ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE); + if (ret) + goto out_destopt; + +out: + return ret; +out_rthdr: + inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); +out_destopt: + inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); + goto out; +}; + +void ipv6_exthdrs_exit(void) +{ + inet6_del_protocol(&nodata_protocol, IPPROTO_NONE); + inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); + inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); +} + +/********************************** + Hop-by-hop options. + **********************************/ + +/* + * Note: we cannot rely on skb->dst before we assign it in ip6_route_input(). + */ +static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb) +{ + return skb->dst ? ip6_dst_idev(skb->dst) : __in6_dev_get(skb->dev); +} + +/* Router Alert as of RFC 2711 */ + +static int ipv6_hop_ra(struct sk_buff *skb, int optoff) +{ + const unsigned char *nh = skb_network_header(skb); + + if (nh[optoff + 1] == 2) { + IP6CB(skb)->ra = optoff; + return 1; + } + LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n", + nh[optoff + 1]); + kfree_skb(skb); + return 0; +} + +/* Jumbo payload */ + +static int ipv6_hop_jumbo(struct sk_buff *skb, int optoff) +{ + const unsigned char *nh = skb_network_header(skb); + u32 pkt_len; + struct net *net = dev_net(skb->dst->dev); + + if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { + LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", + nh[optoff+1]); + IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), + IPSTATS_MIB_INHDRERRORS); + goto drop; + } + + pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); + if (pkt_len <= IPV6_MAXPLEN) { + IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), + IPSTATS_MIB_INHDRERRORS); + icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2); + return 0; + } + if (ipv6_hdr(skb)->payload_len) { + IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), + IPSTATS_MIB_INHDRERRORS); + icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff); + return 0; + } + + if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { + IP6_INC_STATS_BH(net, ipv6_skb_idev(skb), + IPSTATS_MIB_INTRUNCATEDPKTS); + goto drop; + } + + if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) + goto drop; + + return 1; + +drop: + kfree_skb(skb); + return 0; +} + +static struct tlvtype_proc tlvprochopopt_lst[] = { + { + .type = IPV6_TLV_ROUTERALERT, + .func = ipv6_hop_ra, + }, + { + .type = IPV6_TLV_JUMBO, + .func = ipv6_hop_jumbo, + }, + { -1, } +}; + +int ipv6_parse_hopopts(struct sk_buff *skb) +{ + struct inet6_skb_parm *opt = IP6CB(skb); + + /* + * skb_network_header(skb) is equal to skb->data, and + * skb_network_header_len(skb) is always equal to + * sizeof(struct ipv6hdr) by definition of + * hop-by-hop options. + */ + if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || + !pskb_may_pull(skb, (sizeof(struct ipv6hdr) + + ((skb_transport_header(skb)[1] + 1) << 3)))) { + kfree_skb(skb); + return -1; + } + + opt->hop = sizeof(struct ipv6hdr); + if (ip6_parse_tlv(tlvprochopopt_lst, skb)) { + skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3; + opt = IP6CB(skb); + opt->nhoff = sizeof(struct ipv6hdr); + return 1; + } + return -1; +} + +/* + * Creating outbound headers. + * + * "build" functions work when skb is filled from head to tail (datagram) + * "push" functions work when headers are added from tail to head (tcp) + * + * In both cases we assume, that caller reserved enough room + * for headers. + */ + +static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, + struct ipv6_rt_hdr *opt, + struct in6_addr **addr_p) +{ + struct rt0_hdr *phdr, *ihdr; + int hops; + + ihdr = (struct rt0_hdr *) opt; + + phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); + memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); + + hops = ihdr->rt_hdr.hdrlen >> 1; + + if (hops > 1) + memcpy(phdr->addr, ihdr->addr + 1, + (hops - 1) * sizeof(struct in6_addr)); + + ipv6_addr_copy(phdr->addr + (hops - 1), *addr_p); + *addr_p = ihdr->addr; + + phdr->rt_hdr.nexthdr = *proto; + *proto = NEXTHDR_ROUTING; +} + +static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) +{ + struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt)); + + memcpy(h, opt, ipv6_optlen(opt)); + h->nexthdr = *proto; + *proto = type; +} + +void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, + u8 *proto, + struct in6_addr **daddr) +{ + if (opt->srcrt) { + ipv6_push_rthdr(skb, proto, opt->srcrt, daddr); + /* + * IPV6_RTHDRDSTOPTS is ignored + * unless IPV6_RTHDR is set (RFC3542). + */ + if (opt->dst0opt) + ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); + } + if (opt->hopopt) + ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); +} + +EXPORT_SYMBOL(ipv6_push_nfrag_opts); + +void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) +{ + if (opt->dst1opt) + ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); +} + +struct ipv6_txoptions * +ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) +{ + struct ipv6_txoptions *opt2; + + opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); + if (opt2) { + long dif = (char*)opt2 - (char*)opt; + memcpy(opt2, opt, opt->tot_len); + if (opt2->hopopt) + *((char**)&opt2->hopopt) += dif; + if (opt2->dst0opt) + *((char**)&opt2->dst0opt) += dif; + if (opt2->dst1opt) + *((char**)&opt2->dst1opt) += dif; + if (opt2->srcrt) + *((char**)&opt2->srcrt) += dif; + } + return opt2; +} + +EXPORT_SYMBOL_GPL(ipv6_dup_options); + +static int ipv6_renew_option(void *ohdr, + struct ipv6_opt_hdr __user *newopt, int newoptlen, + int inherit, + struct ipv6_opt_hdr **hdr, + char **p) +{ + if (inherit) { + if (ohdr) { + memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr)); + *hdr = (struct ipv6_opt_hdr *)*p; + *p += CMSG_ALIGN(ipv6_optlen(*(struct ipv6_opt_hdr **)hdr)); + } + } else { + if (newopt) { + if (copy_from_user(*p, newopt, newoptlen)) + return -EFAULT; + *hdr = (struct ipv6_opt_hdr *)*p; + if (ipv6_optlen(*(struct ipv6_opt_hdr **)hdr) > newoptlen) + return -EINVAL; + *p += CMSG_ALIGN(newoptlen); + } + } + return 0; +} + +struct ipv6_txoptions * +ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, + int newtype, + struct ipv6_opt_hdr __user *newopt, int newoptlen) +{ + int tot_len = 0; + char *p; + struct ipv6_txoptions *opt2; + int err; + + if (opt) { + if (newtype != IPV6_HOPOPTS && opt->hopopt) + tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); + if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) + tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); + if (newtype != IPV6_RTHDR && opt->srcrt) + tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); + if (newtype != IPV6_DSTOPTS && opt->dst1opt) + tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); + } + + if (newopt && newoptlen) + tot_len += CMSG_ALIGN(newoptlen); + + if (!tot_len) + return NULL; + + tot_len += sizeof(*opt2); + opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); + if (!opt2) + return ERR_PTR(-ENOBUFS); + + memset(opt2, 0, tot_len); + + opt2->tot_len = tot_len; + p = (char *)(opt2 + 1); + + err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen, + newtype != IPV6_HOPOPTS, + &opt2->hopopt, &p); + if (err) + goto out; + + err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen, + newtype != IPV6_RTHDRDSTOPTS, + &opt2->dst0opt, &p); + if (err) + goto out; + + err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen, + newtype != IPV6_RTHDR, + (struct ipv6_opt_hdr **)&opt2->srcrt, &p); + if (err) + goto out; + + err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen, + newtype != IPV6_DSTOPTS, + &opt2->dst1opt, &p); + if (err) + goto out; + + opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + + (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + + (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); + opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); + + return opt2; +out: + sock_kfree_s(sk, opt2, opt2->tot_len); + return ERR_PTR(err); +} + +struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space, + struct ipv6_txoptions *opt) +{ + /* + * ignore the dest before srcrt unless srcrt is being included. + * --yoshfuji + */ + if (opt && opt->dst0opt && !opt->srcrt) { + if (opt_space != opt) { + memcpy(opt_space, opt, sizeof(*opt_space)); + opt = opt_space; + } + opt->opt_nflen -= ipv6_optlen(opt->dst0opt); + opt->dst0opt = NULL; + } + + return opt; +} + |