From f6d8bd051c391c1c0458a30b2a7abcd939329259 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 21 Apr 2011 09:45:37 +0000 Subject: inet: add RCU protection to inet->opt We lack proper synchronization to manipulate inet->opt ip_options Problem is ip_make_skb() calls ip_setup_cork() and ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options), without any protection against another thread manipulating inet->opt. Another thread can change inet->opt pointer and free old one under us. Use RCU to protect inet->opt (changed to inet->inet_opt). Instead of handling atomic refcounts, just copy ip_options when necessary, to avoid cache line dirtying. We cant insert an rcu_head in struct ip_options since its included in skb->cb[], so this patch is large because I had to introduce a new ip_options_rcu structure. Signed-off-by: Eric Dumazet Cc: Herbert Xu Signed-off-by: David S. Miller --- include/net/inet_sock.h | 14 +++-- include/net/ip.h | 11 ++-- net/dccp/ipv4.c | 16 +++--- net/dccp/ipv6.c | 2 +- net/ipv4/af_inet.c | 17 ++++-- net/ipv4/cipso_ipv4.c | 113 ++++++++++++++++++++++------------------ net/ipv4/icmp.c | 23 ++++---- net/ipv4/inet_connection_sock.c | 6 +-- net/ipv4/ip_options.c | 38 +++++++------- net/ipv4/ip_output.c | 44 ++++++++-------- net/ipv4/ip_sockglue.c | 35 +++++++++---- net/ipv4/raw.c | 19 +++++-- net/ipv4/syncookies.c | 4 +- net/ipv4/tcp_ipv4.c | 34 +++++++----- net/ipv4/udp.c | 21 ++++++-- net/ipv6/tcp_ipv6.c | 2 +- net/l2tp/l2tp_ip.c | 10 ++-- 17 files changed, 241 insertions(+), 168 deletions(-) diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index 7a37369..ed2ba6e 100644 --- a/include/net/inet_sock.h +++ b/include/net/inet_sock.h @@ -57,7 +57,15 @@ struct ip_options { unsigned char __data[0]; }; -#define optlength(opt) (sizeof(struct ip_options) + opt->optlen) +struct ip_options_rcu { + struct rcu_head rcu; + struct ip_options opt; +}; + +struct ip_options_data { + struct ip_options_rcu opt; + char data[40]; +}; struct inet_request_sock { struct request_sock req; @@ -78,7 +86,7 @@ struct inet_request_sock { acked : 1, no_srccheck: 1; kmemcheck_bitfield_end(flags); - struct ip_options *opt; + struct ip_options_rcu *opt; }; static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk) @@ -140,7 +148,7 @@ struct inet_sock { __be16 inet_sport; __u16 inet_id; - struct ip_options *opt; + struct ip_options_rcu __rcu *inet_opt; __u8 tos; __u8 min_ttl; __u8 mc_ttl; diff --git a/include/net/ip.h b/include/net/ip.h index 7c41658..3a59bf9 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -52,7 +52,7 @@ static inline unsigned int ip_hdrlen(const struct sk_buff *skb) struct ipcm_cookie { __be32 addr; int oif; - struct ip_options *opt; + struct ip_options_rcu *opt; __u8 tx_flags; }; @@ -92,7 +92,7 @@ extern int igmp_mc_proc_init(void); extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, __be32 saddr, __be32 daddr, - struct ip_options *opt); + struct ip_options_rcu *opt); extern int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev); extern int ip_local_deliver(struct sk_buff *skb); @@ -416,14 +416,15 @@ extern int ip_forward(struct sk_buff *skb); * Functions provided by ip_options.c */ -extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag); +extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, + __be32 daddr, struct rtable *rt, int is_frag); extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); extern void ip_options_fragment(struct sk_buff *skb); extern int ip_options_compile(struct net *net, struct ip_options *opt, struct sk_buff *skb); -extern int ip_options_get(struct net *net, struct ip_options **optp, +extern int ip_options_get(struct net *net, struct ip_options_rcu **optp, unsigned char *data, int optlen); -extern int ip_options_get_from_user(struct net *net, struct ip_options **optp, +extern int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp, unsigned char __user *data, int optlen); extern void ip_options_undo(struct ip_options * opt); extern void ip_forward_options(struct sk_buff *skb); diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c index b92ab65..cbbcc6c 100644 --- a/net/dccp/ipv4.c +++ b/net/dccp/ipv4.c @@ -48,6 +48,7 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) struct flowi4 fl4; struct rtable *rt; int err; + struct ip_options_rcu *inet_opt; dp->dccps_role = DCCP_ROLE_CLIENT; @@ -58,10 +59,13 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) return -EAFNOSUPPORT; nexthop = daddr = usin->sin_addr.s_addr; - if (inet->opt != NULL && inet->opt->srr) { + + inet_opt = rcu_dereference_protected(inet->inet_opt, + sock_owned_by_user(sk)); + if (inet_opt != NULL && inet_opt->opt.srr) { if (daddr == 0) return -EINVAL; - nexthop = inet->opt->faddr; + nexthop = inet_opt->opt.faddr; } orig_sport = inet->inet_sport; @@ -78,7 +82,7 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) return -ENETUNREACH; } - if (inet->opt == NULL || !inet->opt->srr) + if (inet_opt == NULL || !inet_opt->opt.srr) daddr = rt->rt_dst; if (inet->inet_saddr == 0) @@ -89,8 +93,8 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) inet->inet_daddr = daddr; inet_csk(sk)->icsk_ext_hdr_len = 0; - if (inet->opt != NULL) - inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen; + if (inet_opt) + inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen; /* * Socket identity is still unknown (sport may be zero). * However we set state to DCCP_REQUESTING and not releasing socket @@ -405,7 +409,7 @@ struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb, newinet->inet_daddr = ireq->rmt_addr; newinet->inet_rcv_saddr = ireq->loc_addr; newinet->inet_saddr = ireq->loc_addr; - newinet->opt = ireq->opt; + newinet->inet_opt = ireq->opt; ireq->opt = NULL; newinet->mc_index = inet_iif(skb); newinet->mc_ttl = ip_hdr(skb)->ttl; diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c index 73add23..8dc4348 100644 --- a/net/dccp/ipv6.c +++ b/net/dccp/ipv6.c @@ -573,7 +573,7 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk, First: no IPv4 options. */ - newinet->opt = NULL; + newinet->inet_opt = NULL; /* Clone RX bits */ newnp->rxopt.all = np->rxopt.all; diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 0413af3..963a621 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -153,7 +153,7 @@ void inet_sock_destruct(struct sock *sk) WARN_ON(sk->sk_wmem_queued); WARN_ON(sk->sk_forward_alloc); - kfree(inet->opt); + kfree(rcu_dereference_protected(inet->inet_opt, 1)); dst_release(rcu_dereference_check(sk->sk_dst_cache, 1)); sk_refcnt_debug_dec(sk); } @@ -1106,9 +1106,12 @@ static int inet_sk_reselect_saddr(struct sock *sk) struct flowi4 fl4; struct rtable *rt; __be32 new_saddr; + struct ip_options_rcu *inet_opt; - if (inet->opt && inet->opt->srr) - daddr = inet->opt->faddr; + inet_opt = rcu_dereference_protected(inet->inet_opt, + sock_owned_by_user(sk)); + if (inet_opt && inet_opt->opt.srr) + daddr = inet_opt->opt.faddr; /* Query new route. */ rt = ip_route_connect(&fl4, daddr, 0, RT_CONN_FLAGS(sk), @@ -1148,6 +1151,7 @@ int inet_sk_rebuild_header(struct sock *sk) struct inet_sock *inet = inet_sk(sk); struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0); __be32 daddr; + struct ip_options_rcu *inet_opt; int err; /* Route is OK, nothing to do. */ @@ -1155,9 +1159,12 @@ int inet_sk_rebuild_header(struct sock *sk) return 0; /* Reroute. */ + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); daddr = inet->inet_daddr; - if (inet->opt && inet->opt->srr) - daddr = inet->opt->faddr; + if (inet_opt && inet_opt->opt.srr) + daddr = inet_opt->opt.faddr; + rcu_read_unlock(); rt = ip_route_output_ports(sock_net(sk), sk, daddr, inet->inet_saddr, inet->inet_dport, inet->inet_sport, sk->sk_protocol, RT_CONN_FLAGS(sk), diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index a0af7ea..2b3c23c 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -1857,6 +1857,11 @@ static int cipso_v4_genopt(unsigned char *buf, u32 buf_len, return CIPSO_V4_HDR_LEN + ret_val; } +static void opt_kfree_rcu(struct rcu_head *head) +{ + kfree(container_of(head, struct ip_options_rcu, rcu)); +} + /** * cipso_v4_sock_setattr - Add a CIPSO option to a socket * @sk: the socket @@ -1879,7 +1884,7 @@ int cipso_v4_sock_setattr(struct sock *sk, unsigned char *buf = NULL; u32 buf_len; u32 opt_len; - struct ip_options *opt = NULL; + struct ip_options_rcu *old, *opt = NULL; struct inet_sock *sk_inet; struct inet_connection_sock *sk_conn; @@ -1915,22 +1920,25 @@ int cipso_v4_sock_setattr(struct sock *sk, ret_val = -ENOMEM; goto socket_setattr_failure; } - memcpy(opt->__data, buf, buf_len); - opt->optlen = opt_len; - opt->cipso = sizeof(struct iphdr); + memcpy(opt->opt.__data, buf, buf_len); + opt->opt.optlen = opt_len; + opt->opt.cipso = sizeof(struct iphdr); kfree(buf); buf = NULL; sk_inet = inet_sk(sk); + + old = rcu_dereference_protected(sk_inet->inet_opt, sock_owned_by_user(sk)); if (sk_inet->is_icsk) { sk_conn = inet_csk(sk); - if (sk_inet->opt) - sk_conn->icsk_ext_hdr_len -= sk_inet->opt->optlen; - sk_conn->icsk_ext_hdr_len += opt->optlen; + if (old) + sk_conn->icsk_ext_hdr_len -= old->opt.optlen; + sk_conn->icsk_ext_hdr_len += opt->opt.optlen; sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); } - opt = xchg(&sk_inet->opt, opt); - kfree(opt); + rcu_assign_pointer(sk_inet->inet_opt, opt); + if (old) + call_rcu(&old->rcu, opt_kfree_rcu); return 0; @@ -1960,7 +1968,7 @@ int cipso_v4_req_setattr(struct request_sock *req, unsigned char *buf = NULL; u32 buf_len; u32 opt_len; - struct ip_options *opt = NULL; + struct ip_options_rcu *opt = NULL; struct inet_request_sock *req_inet; /* We allocate the maximum CIPSO option size here so we are probably @@ -1988,15 +1996,16 @@ int cipso_v4_req_setattr(struct request_sock *req, ret_val = -ENOMEM; goto req_setattr_failure; } - memcpy(opt->__data, buf, buf_len); - opt->optlen = opt_len; - opt->cipso = sizeof(struct iphdr); + memcpy(opt->opt.__data, buf, buf_len); + opt->opt.optlen = opt_len; + opt->opt.cipso = sizeof(struct iphdr); kfree(buf); buf = NULL; req_inet = inet_rsk(req); opt = xchg(&req_inet->opt, opt); - kfree(opt); + if (opt) + call_rcu(&opt->rcu, opt_kfree_rcu); return 0; @@ -2016,34 +2025,34 @@ req_setattr_failure: * values on failure. * */ -static int cipso_v4_delopt(struct ip_options **opt_ptr) +static int cipso_v4_delopt(struct ip_options_rcu **opt_ptr) { int hdr_delta = 0; - struct ip_options *opt = *opt_ptr; + struct ip_options_rcu *opt = *opt_ptr; - if (opt->srr || opt->rr || opt->ts || opt->router_alert) { + if (opt->opt.srr || opt->opt.rr || opt->opt.ts || opt->opt.router_alert) { u8 cipso_len; u8 cipso_off; unsigned char *cipso_ptr; int iter; int optlen_new; - cipso_off = opt->cipso - sizeof(struct iphdr); - cipso_ptr = &opt->__data[cipso_off]; + cipso_off = opt->opt.cipso - sizeof(struct iphdr); + cipso_ptr = &opt->opt.__data[cipso_off]; cipso_len = cipso_ptr[1]; - if (opt->srr > opt->cipso) - opt->srr -= cipso_len; - if (opt->rr > opt->cipso) - opt->rr -= cipso_len; - if (opt->ts > opt->cipso) - opt->ts -= cipso_len; - if (opt->router_alert > opt->cipso) - opt->router_alert -= cipso_len; - opt->cipso = 0; + if (opt->opt.srr > opt->opt.cipso) + opt->opt.srr -= cipso_len; + if (opt->opt.rr > opt->opt.cipso) + opt->opt.rr -= cipso_len; + if (opt->opt.ts > opt->opt.cipso) + opt->opt.ts -= cipso_len; + if (opt->opt.router_alert > opt->opt.cipso) + opt->opt.router_alert -= cipso_len; + opt->opt.cipso = 0; memmove(cipso_ptr, cipso_ptr + cipso_len, - opt->optlen - cipso_off - cipso_len); + opt->opt.optlen - cipso_off - cipso_len); /* determining the new total option length is tricky because of * the padding necessary, the only thing i can think to do at @@ -2052,21 +2061,21 @@ static int cipso_v4_delopt(struct ip_options **opt_ptr) * from there we can determine the new total option length */ iter = 0; optlen_new = 0; - while (iter < opt->optlen) - if (opt->__data[iter] != IPOPT_NOP) { - iter += opt->__data[iter + 1]; + while (iter < opt->opt.optlen) + if (opt->opt.__data[iter] != IPOPT_NOP) { + iter += opt->opt.__data[iter + 1]; optlen_new = iter; } else iter++; - hdr_delta = opt->optlen; - opt->optlen = (optlen_new + 3) & ~3; - hdr_delta -= opt->optlen; + hdr_delta = opt->opt.optlen; + opt->opt.optlen = (optlen_new + 3) & ~3; + hdr_delta -= opt->opt.optlen; } else { /* only the cipso option was present on the socket so we can * remove the entire option struct */ *opt_ptr = NULL; - hdr_delta = opt->optlen; - kfree(opt); + hdr_delta = opt->opt.optlen; + call_rcu(&opt->rcu, opt_kfree_rcu); } return hdr_delta; @@ -2083,15 +2092,15 @@ static int cipso_v4_delopt(struct ip_options **opt_ptr) void cipso_v4_sock_delattr(struct sock *sk) { int hdr_delta; - struct ip_options *opt; + struct ip_options_rcu *opt; struct inet_sock *sk_inet; sk_inet = inet_sk(sk); - opt = sk_inet->opt; - if (opt == NULL || opt->cipso == 0) + opt = rcu_dereference_protected(sk_inet->inet_opt, 1); + if (opt == NULL || opt->opt.cipso == 0) return; - hdr_delta = cipso_v4_delopt(&sk_inet->opt); + hdr_delta = cipso_v4_delopt(&sk_inet->inet_opt); if (sk_inet->is_icsk && hdr_delta > 0) { struct inet_connection_sock *sk_conn = inet_csk(sk); sk_conn->icsk_ext_hdr_len -= hdr_delta; @@ -2109,12 +2118,12 @@ void cipso_v4_sock_delattr(struct sock *sk) */ void cipso_v4_req_delattr(struct request_sock *req) { - struct ip_options *opt; + struct ip_options_rcu *opt; struct inet_request_sock *req_inet; req_inet = inet_rsk(req); opt = req_inet->opt; - if (opt == NULL || opt->cipso == 0) + if (opt == NULL || opt->opt.cipso == 0) return; cipso_v4_delopt(&req_inet->opt); @@ -2184,14 +2193,18 @@ getattr_return: */ int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) { - struct ip_options *opt; + struct ip_options_rcu *opt; + int res = -ENOMSG; - opt = inet_sk(sk)->opt; - if (opt == NULL || opt->cipso == 0) - return -ENOMSG; - - return cipso_v4_getattr(opt->__data + opt->cipso - sizeof(struct iphdr), - secattr); + rcu_read_lock(); + opt = rcu_dereference(inet_sk(sk)->inet_opt); + if (opt && opt->opt.cipso) + res = cipso_v4_getattr(opt->opt.__data + + opt->opt.cipso - + sizeof(struct iphdr), + secattr); + rcu_read_unlock(); + return res; } /** diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 74e35e5..cfeca3c 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -108,8 +108,7 @@ struct icmp_bxm { __be32 times[3]; } data; int head_len; - struct ip_options replyopts; - unsigned char optbuf[40]; + struct ip_options_data replyopts; }; /* An array of errno for error messages from dest unreach. */ @@ -333,7 +332,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) struct inet_sock *inet; __be32 daddr; - if (ip_options_echo(&icmp_param->replyopts, skb)) + if (ip_options_echo(&icmp_param->replyopts.opt.opt, skb)) return; sk = icmp_xmit_lock(net); @@ -347,10 +346,10 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) daddr = ipc.addr = rt->rt_src; ipc.opt = NULL; ipc.tx_flags = 0; - if (icmp_param->replyopts.optlen) { - ipc.opt = &icmp_param->replyopts; - if (ipc.opt->srr) - daddr = icmp_param->replyopts.faddr; + if (icmp_param->replyopts.opt.opt.optlen) { + ipc.opt = &icmp_param->replyopts.opt; + if (ipc.opt->opt.srr) + daddr = icmp_param->replyopts.opt.opt.faddr; } { struct flowi4 fl4 = { @@ -379,8 +378,8 @@ static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in, struct icmp_bxm *param) { struct flowi4 fl4 = { - .daddr = (param->replyopts.srr ? - param->replyopts.faddr : iph->saddr), + .daddr = (param->replyopts.opt.opt.srr ? + param->replyopts.opt.opt.faddr : iph->saddr), .saddr = saddr, .flowi4_tos = RT_TOS(tos), .flowi4_proto = IPPROTO_ICMP, @@ -581,7 +580,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) IPTOS_PREC_INTERNETCONTROL) : iph->tos; - if (ip_options_echo(&icmp_param.replyopts, skb_in)) + if (ip_options_echo(&icmp_param.replyopts.opt.opt, skb_in)) goto out_unlock; @@ -597,7 +596,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) icmp_param.offset = skb_network_offset(skb_in); inet_sk(sk)->tos = tos; ipc.addr = iph->saddr; - ipc.opt = &icmp_param.replyopts; + ipc.opt = &icmp_param.replyopts.opt; ipc.tx_flags = 0; rt = icmp_route_lookup(net, skb_in, iph, saddr, tos, @@ -613,7 +612,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) room = dst_mtu(&rt->dst); if (room > 576) room = 576; - room -= sizeof(struct iphdr) + icmp_param.replyopts.optlen; + room -= sizeof(struct iphdr) + icmp_param.replyopts.opt.opt.optlen; room -= sizeof(struct icmphdr); icmp_param.data_len = skb_in->len - icmp_param.offset; diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 8514db5..3282cb2 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -354,20 +354,20 @@ struct dst_entry *inet_csk_route_req(struct sock *sk, { struct rtable *rt; const struct inet_request_sock *ireq = inet_rsk(req); - struct ip_options *opt = inet_rsk(req)->opt; + struct ip_options_rcu *opt = inet_rsk(req)->opt; struct net *net = sock_net(sk); struct flowi4 fl4; flowi4_init_output(&fl4, sk->sk_bound_dev_if, sk->sk_mark, RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, sk->sk_protocol, inet_sk_flowi_flags(sk), - (opt && opt->srr) ? opt->faddr : ireq->rmt_addr, + (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr, ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport); security_req_classify_flow(req, flowi4_to_flowi(&fl4)); rt = ip_route_output_flow(net, &fl4, sk); if (IS_ERR(rt)) goto no_route; - if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) + if (opt && opt->opt.is_strictroute && rt->rt_dst != rt->rt_gateway) goto route_err; return &rt->dst; diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c index 2391b24..01fc409 100644 --- a/net/ipv4/ip_options.c +++ b/net/ipv4/ip_options.c @@ -36,7 +36,7 @@ * saddr is address of outgoing interface. */ -void ip_options_build(struct sk_buff * skb, struct ip_options * opt, +void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag) { unsigned char *iph = skb_network_header(skb); @@ -83,9 +83,9 @@ void ip_options_build(struct sk_buff * skb, struct ip_options * opt, * NOTE: dopt cannot point to skb. */ -int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb) +int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb) { - struct ip_options *sopt; + const struct ip_options *sopt; unsigned char *sptr, *dptr; int soffset, doffset; int optlen; @@ -95,10 +95,8 @@ int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb) sopt = &(IPCB(skb)->opt); - if (sopt->optlen == 0) { - dopt->optlen = 0; + if (sopt->optlen == 0) return 0; - } sptr = skb_network_header(skb); dptr = dopt->__data; @@ -157,7 +155,7 @@ int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb) dopt->optlen += optlen; } if (sopt->srr) { - unsigned char * start = sptr+sopt->srr; + unsigned char *start = sptr+sopt->srr; __be32 faddr; optlen = start[1]; @@ -499,19 +497,19 @@ void ip_options_undo(struct ip_options * opt) } } -static struct ip_options *ip_options_get_alloc(const int optlen) +static struct ip_options_rcu *ip_options_get_alloc(const int optlen) { - return kzalloc(sizeof(struct ip_options) + ((optlen + 3) & ~3), + return kzalloc(sizeof(struct ip_options_rcu) + ((optlen + 3) & ~3), GFP_KERNEL); } -static int ip_options_get_finish(struct net *net, struct ip_options **optp, - struct ip_options *opt, int optlen) +static int ip_options_get_finish(struct net *net, struct ip_options_rcu **optp, + struct ip_options_rcu *opt, int optlen) { while (optlen & 3) - opt->__data[optlen++] = IPOPT_END; - opt->optlen = optlen; - if (optlen && ip_options_compile(net, opt, NULL)) { + opt->opt.__data[optlen++] = IPOPT_END; + opt->opt.optlen = optlen; + if (optlen && ip_options_compile(net, &opt->opt, NULL)) { kfree(opt); return -EINVAL; } @@ -520,29 +518,29 @@ static int ip_options_get_finish(struct net *net, struct ip_options **optp, return 0; } -int ip_options_get_from_user(struct net *net, struct ip_options **optp, +int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp, unsigned char __user *data, int optlen) { - struct ip_options *opt = ip_options_get_alloc(optlen); + struct ip_options_rcu *opt = ip_options_get_alloc(optlen); if (!opt) return -ENOMEM; - if (optlen && copy_from_user(opt->__data, data, optlen)) { + if (optlen && copy_from_user(opt->opt.__data, data, optlen)) { kfree(opt); return -EFAULT; } return ip_options_get_finish(net, optp, opt, optlen); } -int ip_options_get(struct net *net, struct ip_options **optp, +int ip_options_get(struct net *net, struct ip_options_rcu **optp, unsigned char *data, int optlen) { - struct ip_options *opt = ip_options_get_alloc(optlen); + struct ip_options_rcu *opt = ip_options_get_alloc(optlen); if (!opt) return -ENOMEM; if (optlen) - memcpy(opt->__data, data, optlen); + memcpy(opt->opt.__data, data, optlen); return ip_options_get_finish(net, optp, opt, optlen); } diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index bdad3d6..362e66f 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -140,14 +140,14 @@ static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) * */ int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, - __be32 saddr, __be32 daddr, struct ip_options *opt) + __be32 saddr, __be32 daddr, struct ip_options_rcu *opt) { struct inet_sock *inet = inet_sk(sk); struct rtable *rt = skb_rtable(skb); struct iphdr *iph; /* Build the IP header. */ - skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); + skb_push(skb, sizeof(struct iphdr) + (opt ? opt->opt.optlen : 0)); skb_reset_network_header(skb); iph = ip_hdr(skb); iph->version = 4; @@ -163,9 +163,9 @@ int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, iph->protocol = sk->sk_protocol; ip_select_ident(iph, &rt->dst, sk); - if (opt && opt->optlen) { - iph->ihl += opt->optlen>>2; - ip_options_build(skb, opt, daddr, rt, 0); + if (opt && opt->opt.optlen) { + iph->ihl += opt->opt.optlen>>2; + ip_options_build(skb, &opt->opt, daddr, rt, 0); } skb->priority = sk->sk_priority; @@ -316,7 +316,7 @@ int ip_queue_xmit(struct sk_buff *skb) { struct sock *sk = skb->sk; struct inet_sock *inet = inet_sk(sk); - struct ip_options *opt = inet->opt; + struct ip_options_rcu *inet_opt; struct rtable *rt; struct iphdr *iph; int res; @@ -325,6 +325,7 @@ int ip_queue_xmit(struct sk_buff *skb) * f.e. by something like SCTP. */ rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); rt = skb_rtable(skb); if (rt != NULL) goto packet_routed; @@ -336,8 +337,8 @@ int ip_queue_xmit(struct sk_buff *skb) /* Use correct destination address if we have options. */ daddr = inet->inet_daddr; - if(opt && opt->srr) - daddr = opt->faddr; + if (inet_opt && inet_opt->opt.srr) + daddr = inet_opt->opt.faddr; /* If this fails, retransmit mechanism of transport layer will * keep trying until route appears or the connection times @@ -357,11 +358,11 @@ int ip_queue_xmit(struct sk_buff *skb) skb_dst_set_noref(skb, &rt->dst); packet_routed: - if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) + if (inet_opt && inet_opt->opt.is_strictroute && rt->rt_dst != rt->rt_gateway) goto no_route; /* OK, we know where to send it, allocate and build IP header. */ - skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); + skb_push(skb, sizeof(struct iphdr) + (inet_opt ? inet_opt->opt.optlen : 0)); skb_reset_network_header(skb); iph = ip_hdr(skb); *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff)); @@ -375,9 +376,9 @@ packet_routed: iph->daddr = rt->rt_dst; /* Transport layer set skb->h.foo itself. */ - if (opt && opt->optlen) { - iph->ihl += opt->optlen >> 2; - ip_options_build(skb, opt, inet->inet_daddr, rt, 0); + if (inet_opt && inet_opt->opt.optlen) { + iph->ihl += inet_opt->opt.optlen >> 2; + ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0); } ip_select_ident_more(iph, &rt->dst, sk, @@ -1033,7 +1034,7 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork, struct ipcm_cookie *ipc, struct rtable **rtp) { struct inet_sock *inet = inet_sk(sk); - struct ip_options *opt; + struct ip_options_rcu *opt; struct rtable *rt; /* @@ -1047,7 +1048,7 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork, if (unlikely(cork->opt == NULL)) return -ENOBUFS; } - memcpy(cork->opt, opt, sizeof(struct ip_options) + opt->optlen); + memcpy(cork->opt, &opt->opt, sizeof(struct ip_options) + opt->opt.optlen); cork->flags |= IPCORK_OPT; cork->addr = ipc->addr; } @@ -1451,26 +1452,23 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *ar unsigned int len) { struct inet_sock *inet = inet_sk(sk); - struct { - struct ip_options opt; - char data[40]; - } replyopts; + struct ip_options_data replyopts; struct ipcm_cookie ipc; __be32 daddr; struct rtable *rt = skb_rtable(skb); - if (ip_options_echo(&replyopts.opt, skb)) + if (ip_options_echo(&replyopts.opt.opt, skb)) return; daddr = ipc.addr = rt->rt_src; ipc.opt = NULL; ipc.tx_flags = 0; - if (replyopts.opt.optlen) { + if (replyopts.opt.opt.optlen) { ipc.opt = &replyopts.opt; - if (ipc.opt->srr) - daddr = replyopts.opt.faddr; + if (replyopts.opt.opt.srr) + daddr = replyopts.opt.opt.faddr; } { diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 9640900..ab0c9ef 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -451,6 +451,11 @@ out: } +static void opt_kfree_rcu(struct rcu_head *head) +{ + kfree(container_of(head, struct ip_options_rcu, rcu)); +} + /* * Socket option code for IP. This is the end of the line after any * TCP,UDP etc options on an IP socket. @@ -497,13 +502,16 @@ static int do_ip_setsockopt(struct sock *sk, int level, switch (optname) { case IP_OPTIONS: { - struct ip_options *opt = NULL; + struct ip_options_rcu *old, *opt = NULL; + if (optlen > 40) goto e_inval; err = ip_options_get_from_user(sock_net(sk), &opt, optval, optlen); if (err) break; + old = rcu_dereference_protected(inet->inet_opt, + sock_owned_by_user(sk)); if (inet->is_icsk) { struct inet_connection_sock *icsk = inet_csk(sk); #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) @@ -512,17 +520,18 @@ static int do_ip_setsockopt(struct sock *sk, int level, (TCPF_LISTEN | TCPF_CLOSE)) && inet->inet_daddr != LOOPBACK4_IPV6)) { #endif - if (inet->opt) - icsk->icsk_ext_hdr_len -= inet->opt->optlen; + if (old) + icsk->icsk_ext_hdr_len -= old->opt.optlen; if (opt) - icsk->icsk_ext_hdr_len += opt->optlen; + icsk->icsk_ext_hdr_len += opt->opt.optlen; icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie); #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) } #endif } - opt = xchg(&inet->opt, opt); - kfree(opt); + rcu_assign_pointer(inet->inet_opt, opt); + if (old) + call_rcu(&old->rcu, opt_kfree_rcu); break; } case IP_PKTINFO: @@ -1081,12 +1090,16 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname, case IP_OPTIONS: { unsigned char optbuf[sizeof(struct ip_options)+40]; - struct ip_options * opt = (struct ip_options *)optbuf; + struct ip_options *opt = (struct ip_options *)optbuf; + struct ip_options_rcu *inet_opt; + + inet_opt = rcu_dereference_protected(inet->inet_opt, + sock_owned_by_user(sk)); opt->optlen = 0; - if (inet->opt) - memcpy(optbuf, inet->opt, - sizeof(struct ip_options)+ - inet->opt->optlen); + if (inet_opt) + memcpy(optbuf, &inet_opt->opt, + sizeof(struct ip_options) + + inet_opt->opt.optlen); release_sock(sk); if (opt->optlen == 0) diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c index abf14db..a8659e0 100644 --- a/net/ipv4/raw.c +++ b/net/ipv4/raw.c @@ -460,6 +460,7 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, __be32 saddr; u8 tos; int err; + struct ip_options_data opt_copy; err = -EMSGSIZE; if (len > 0xFFFF) @@ -520,8 +521,18 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, saddr = ipc.addr; ipc.addr = daddr; - if (!ipc.opt) - ipc.opt = inet->opt; + if (!ipc.opt) { + struct ip_options_rcu *inet_opt; + + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); + if (inet_opt) { + memcpy(&opt_copy, inet_opt, + sizeof(*inet_opt) + inet_opt->opt.optlen); + ipc.opt = &opt_copy.opt; + } + rcu_read_unlock(); + } if (ipc.opt) { err = -EINVAL; @@ -530,10 +541,10 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, */ if (inet->hdrincl) goto done; - if (ipc.opt->srr) { + if (ipc.opt->opt.srr) { if (!daddr) goto done; - daddr = ipc.opt->faddr; + daddr = ipc.opt->opt.faddr; } } tos = RT_CONN_FLAGS(sk); diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index 71e0296..2646149 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -321,10 +321,10 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb, * the ACK carries the same options again (see RFC1122 4.2.3.8) */ if (opt && opt->optlen) { - int opt_size = sizeof(struct ip_options) + opt->optlen; + int opt_size = sizeof(struct ip_options_rcu) + opt->optlen; ireq->opt = kmalloc(opt_size, GFP_ATOMIC); - if (ireq->opt != NULL && ip_options_echo(ireq->opt, skb)) { + if (ireq->opt != NULL && ip_options_echo(&ireq->opt->opt, skb)) { kfree(ireq->opt); ireq->opt = NULL; } diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 310454c..d60732f 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -154,6 +154,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) struct flowi4 fl4; struct rtable *rt; int err; + struct ip_options_rcu *inet_opt; if (addr_len < sizeof(struct sockaddr_in)) return -EINVAL; @@ -162,10 +163,12 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) return -EAFNOSUPPORT; nexthop = daddr = usin->sin_addr.s_addr; - if (inet->opt && inet->opt->srr) { + inet_opt = rcu_dereference_protected(inet->inet_opt, + sock_owned_by_user(sk)); + if (inet_opt && inet_opt->opt.srr) { if (!daddr) return -EINVAL; - nexthop = inet->opt->faddr; + nexthop = inet_opt->opt.faddr; } orig_sport = inet->inet_sport; @@ -186,7 +189,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) return -ENETUNREACH; } - if (!inet->opt || !inet->opt->srr) + if (!inet_opt || !inet_opt->opt.srr) daddr = rt->rt_dst; if (!inet->inet_saddr) @@ -222,8 +225,8 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) inet->inet_daddr = daddr; inet_csk(sk)->icsk_ext_hdr_len = 0; - if (inet->opt) - inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen; + if (inet_opt) + inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen; tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT; @@ -820,17 +823,18 @@ static void syn_flood_warning(const struct sk_buff *skb) /* * Save and compile IPv4 options into the request_sock if needed. */ -static struct ip_options *tcp_v4_save_options(struct sock *sk, - struct sk_buff *skb) +static struct ip_options_rcu *tcp_v4_save_options(struct sock *sk, + struct sk_buff *skb) { - struct ip_options *opt = &(IPCB(skb)->opt); - struct ip_options *dopt = NULL; + const struct ip_options *opt = &(IPCB(skb)->opt); + struct ip_options_rcu *dopt = NULL; if (opt && opt->optlen) { - int opt_size = optlength(opt); + int opt_size = sizeof(*dopt) + opt->optlen; + dopt = kmalloc(opt_size, GFP_ATOMIC); if (dopt) { - if (ip_options_echo(dopt, skb)) { + if (ip_options_echo(&dopt->opt, skb)) { kfree(dopt); dopt = NULL; } @@ -1411,6 +1415,7 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, #ifdef CONFIG_TCP_MD5SIG struct tcp_md5sig_key *key; #endif + struct ip_options_rcu *inet_opt; if (sk_acceptq_is_full(sk)) goto exit_overflow; @@ -1431,13 +1436,14 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, newinet->inet_daddr = ireq->rmt_addr; newinet->inet_rcv_saddr = ireq->loc_addr; newinet->inet_saddr = ireq->loc_addr; - newinet->opt = ireq->opt; + inet_opt = ireq->opt; + rcu_assign_pointer(newinet->inet_opt, inet_opt); ireq->opt = NULL; newinet->mc_index = inet_iif(skb); newinet->mc_ttl = ip_hdr(skb)->ttl; inet_csk(newsk)->icsk_ext_hdr_len = 0; - if (newinet->opt) - inet_csk(newsk)->icsk_ext_hdr_len = newinet->opt->optlen; + if (inet_opt) + inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen; newinet->inet_id = newtp->write_seq ^ jiffies; tcp_mtup_init(newsk); diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index bc0dab2..544f435 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -804,6 +804,7 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); struct sk_buff *skb; + struct ip_options_data opt_copy; if (len > 0xFFFF) return -EMSGSIZE; @@ -877,22 +878,32 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, free = 1; connected = 0; } - if (!ipc.opt) - ipc.opt = inet->opt; + if (!ipc.opt) { + struct ip_options_rcu *inet_opt; + + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); + if (inet_opt) { + memcpy(&opt_copy, inet_opt, + sizeof(*inet_opt) + inet_opt->opt.optlen); + ipc.opt = &opt_copy.opt; + } + rcu_read_unlock(); + } saddr = ipc.addr; ipc.addr = faddr = daddr; - if (ipc.opt && ipc.opt->srr) { + if (ipc.opt && ipc.opt->opt.srr) { if (!daddr) return -EINVAL; - faddr = ipc.opt->faddr; + faddr = ipc.opt->opt.faddr; connected = 0; } tos = RT_TOS(inet->tos); if (sock_flag(sk, SOCK_LOCALROUTE) || (msg->msg_flags & MSG_DONTROUTE) || - (ipc.opt && ipc.opt->is_strictroute)) { + (ipc.opt && ipc.opt->opt.is_strictroute)) { tos |= RTO_ONLINK; connected = 0; } diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index cb7658a..8683664 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1469,7 +1469,7 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb, First: no IPv4 options. */ - newinet->opt = NULL; + newinet->inet_opt = NULL; newnp->ipv6_fl_list = NULL; /* Clone RX bits */ diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c index cc67367..962a607 100644 --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -416,7 +416,6 @@ static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m int rc; struct l2tp_ip_sock *lsa = l2tp_ip_sk(sk); struct inet_sock *inet = inet_sk(sk); - struct ip_options *opt = inet->opt; struct rtable *rt = NULL; int connected = 0; __be32 daddr; @@ -471,9 +470,14 @@ static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m rt = (struct rtable *) __sk_dst_check(sk, 0); if (rt == NULL) { + struct ip_options_rcu *inet_opt; + + inet_opt = rcu_dereference_protected(inet->inet_opt, + sock_owned_by_user(sk)); + /* Use correct destination address if we have options. */ - if (opt && opt->srr) - daddr = opt->faddr; + if (inet_opt && inet_opt->opt.srr) + daddr = inet_opt->opt.faddr; /* If this fails, retransmit mechanism of transport layer will * keep trying until route appears or the connection times -- cgit v1.1