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ipv4: Pass flow keys down into datagram packet building engine.
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This way ip_output.c no longer needs rt->rt_{src,dst}.

We already have these keys sitting, ready and waiting, on the stack or
in a socket structure.

Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller committed May 9, 2011
1 parent e474995 commit 77968b7
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Showing 5 changed files with 91 additions and 93 deletions.
8 changes: 5 additions & 3 deletions include/net/ip.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -117,22 +117,24 @@ extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int od
extern ssize_t ip_append_page(struct sock *sk, struct page *page,
int offset, size_t size, int flags);
extern struct sk_buff *__ip_make_skb(struct sock *sk,
struct flowi4 *fl4,
struct sk_buff_head *queue,
struct inet_cork *cork);
extern int ip_send_skb(struct sk_buff *skb);
extern int ip_push_pending_frames(struct sock *sk);
extern int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
extern void ip_flush_pending_frames(struct sock *sk);
extern struct sk_buff *ip_make_skb(struct sock *sk,
struct flowi4 *fl4,
int getfrag(void *from, char *to, int offset, int len,
int odd, struct sk_buff *skb),
void *from, int length, int transhdrlen,
struct ipcm_cookie *ipc,
struct rtable **rtp,
unsigned int flags);

static inline struct sk_buff *ip_finish_skb(struct sock *sk)
static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
{
return __ip_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
}

/* datagram.c */
Expand Down
74 changes: 36 additions & 38 deletions net/ipv4/icmp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -290,6 +290,7 @@ static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd,
}

static void icmp_push_reply(struct icmp_bxm *icmp_param,
struct flowi4 *fl4,
struct ipcm_cookie *ipc, struct rtable **rt)
{
struct sock *sk;
Expand All @@ -315,7 +316,7 @@ static void icmp_push_reply(struct icmp_bxm *icmp_param,
icmp_param->head_len, csum);
icmph->checksum = csum_fold(csum);
skb->ip_summed = CHECKSUM_NONE;
ip_push_pending_frames(sk);
ip_push_pending_frames(sk, fl4);
}
}

Expand All @@ -328,6 +329,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
struct ipcm_cookie ipc;
struct rtable *rt = skb_rtable(skb);
struct net *net = dev_net(rt->dst.dev);
struct flowi4 fl4;
struct sock *sk;
struct inet_sock *inet;
__be32 daddr;
Expand All @@ -351,57 +353,52 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
if (ipc.opt->opt.srr)
daddr = icmp_param->replyopts.opt.opt.faddr;
}
{
struct flowi4 fl4 = {
.daddr = daddr,
.saddr = rt->rt_spec_dst,
.flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
.flowi4_proto = IPPROTO_ICMP,
};
security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
rt = ip_route_output_key(net, &fl4);
if (IS_ERR(rt))
goto out_unlock;
}
memset(&fl4, 0, sizeof(fl4));
fl4.daddr = daddr;
fl4.saddr = rt->rt_spec_dst;
fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
fl4.flowi4_proto = IPPROTO_ICMP;
security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
rt = ip_route_output_key(net, &fl4);
if (IS_ERR(rt))
goto out_unlock;
if (icmpv4_xrlim_allow(net, rt, icmp_param->data.icmph.type,
icmp_param->data.icmph.code))
icmp_push_reply(icmp_param, &ipc, &rt);
icmp_push_reply(icmp_param, &fl4, &ipc, &rt);
ip_rt_put(rt);
out_unlock:
icmp_xmit_unlock(sk);
}

static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
static struct rtable *icmp_route_lookup(struct net *net,
struct flowi4 *fl4,
struct sk_buff *skb_in,
const struct iphdr *iph,
__be32 saddr, u8 tos,
int type, int code,
struct icmp_bxm *param)
{
struct flowi4 fl4 = {
.daddr = (param->replyopts.opt.opt.srr ?
param->replyopts.opt.opt.faddr : iph->saddr),
.saddr = saddr,
.flowi4_tos = RT_TOS(tos),
.flowi4_proto = IPPROTO_ICMP,
.fl4_icmp_type = type,
.fl4_icmp_code = code,
};
struct rtable *rt, *rt2;
int err;

security_skb_classify_flow(skb_in, flowi4_to_flowi(&fl4));
rt = __ip_route_output_key(net, &fl4);
memset(fl4, 0, sizeof(*fl4));
fl4->daddr = (param->replyopts.opt.opt.srr ?
param->replyopts.opt.opt.faddr : iph->saddr);
fl4->saddr = saddr;
fl4->flowi4_tos = RT_TOS(tos);
fl4->flowi4_proto = IPPROTO_ICMP;
fl4->fl4_icmp_type = type;
fl4->fl4_icmp_code = code;
security_skb_classify_flow(skb_in, flowi4_to_flowi(fl4));
rt = __ip_route_output_key(net, fl4);
if (IS_ERR(rt))
return rt;

/* No need to clone since we're just using its address. */
rt2 = rt;

if (!fl4.saddr)
fl4.saddr = rt->rt_src;

rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
flowi4_to_flowi(&fl4), NULL, 0);
flowi4_to_flowi(fl4), NULL, 0);
if (!IS_ERR(rt)) {
if (rt != rt2)
return rt;
Expand All @@ -410,27 +407,27 @@ static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
} else
return rt;

err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(&fl4), AF_INET);
err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(fl4), AF_INET);
if (err)
goto relookup_failed;

if (inet_addr_type(net, fl4.saddr) == RTN_LOCAL) {
rt2 = __ip_route_output_key(net, &fl4);
if (inet_addr_type(net, fl4->saddr) == RTN_LOCAL) {
rt2 = __ip_route_output_key(net, fl4);
if (IS_ERR(rt2))
err = PTR_ERR(rt2);
} else {
struct flowi4 fl4_2 = {};
unsigned long orefdst;

fl4_2.daddr = fl4.saddr;
fl4_2.daddr = fl4->saddr;
rt2 = ip_route_output_key(net, &fl4_2);
if (IS_ERR(rt2)) {
err = PTR_ERR(rt2);
goto relookup_failed;
}
/* Ugh! */
orefdst = skb_in->_skb_refdst; /* save old refdst */
err = ip_route_input(skb_in, fl4.daddr, fl4.saddr,
err = ip_route_input(skb_in, fl4->daddr, fl4->saddr,
RT_TOS(tos), rt2->dst.dev);

dst_release(&rt2->dst);
Expand All @@ -442,7 +439,7 @@ static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
goto relookup_failed;

rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst,
flowi4_to_flowi(&fl4), NULL,
flowi4_to_flowi(fl4), NULL,
XFRM_LOOKUP_ICMP);
if (!IS_ERR(rt2)) {
dst_release(&rt->dst);
Expand Down Expand Up @@ -481,6 +478,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
struct icmp_bxm icmp_param;
struct rtable *rt = skb_rtable(skb_in);
struct ipcm_cookie ipc;
struct flowi4 fl4;
__be32 saddr;
u8 tos;
struct net *net;
Expand Down Expand Up @@ -599,7 +597,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
ipc.opt = &icmp_param.replyopts.opt;
ipc.tx_flags = 0;

rt = icmp_route_lookup(net, skb_in, iph, saddr, tos,
rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos,
type, code, &icmp_param);
if (IS_ERR(rt))
goto out_unlock;
Expand All @@ -620,7 +618,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
icmp_param.data_len = room;
icmp_param.head_len = sizeof(struct icmphdr);

icmp_push_reply(&icmp_param, &ipc, &rt);
icmp_push_reply(&icmp_param, &fl4, &ipc, &rt);
ende:
ip_rt_put(rt);
out_unlock:
Expand Down
39 changes: 19 additions & 20 deletions net/ipv4/ip_output.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1267,6 +1267,7 @@ static void ip_cork_release(struct inet_cork *cork)
* and push them out.
*/
struct sk_buff *__ip_make_skb(struct sock *sk,
struct flowi4 *fl4,
struct sk_buff_head *queue,
struct inet_cork *cork)
{
Expand Down Expand Up @@ -1333,8 +1334,8 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
ip_select_ident(iph, &rt->dst, sk);
iph->ttl = ttl;
iph->protocol = sk->sk_protocol;
iph->saddr = rt->rt_src;
iph->daddr = rt->rt_dst;
iph->saddr = fl4->saddr;
iph->daddr = fl4->daddr;

skb->priority = sk->sk_priority;
skb->mark = sk->sk_mark;
Expand Down Expand Up @@ -1370,11 +1371,11 @@ int ip_send_skb(struct sk_buff *skb)
return err;
}

int ip_push_pending_frames(struct sock *sk)
int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4)
{
struct sk_buff *skb;

skb = ip_finish_skb(sk);
skb = ip_finish_skb(sk, fl4);
if (!skb)
return 0;

Expand Down Expand Up @@ -1403,6 +1404,7 @@ void ip_flush_pending_frames(struct sock *sk)
}

struct sk_buff *ip_make_skb(struct sock *sk,
struct flowi4 *fl4,
int getfrag(void *from, char *to, int offset,
int len, int odd, struct sk_buff *skb),
void *from, int length, int transhdrlen,
Expand Down Expand Up @@ -1432,7 +1434,7 @@ struct sk_buff *ip_make_skb(struct sock *sk,
return ERR_PTR(err);
}

return __ip_make_skb(sk, &queue, &cork);
return __ip_make_skb(sk, fl4, &queue, &cork);
}

/*
Expand Down Expand Up @@ -1461,6 +1463,7 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *ar
struct inet_sock *inet = inet_sk(sk);
struct ip_options_data replyopts;
struct ipcm_cookie ipc;
struct flowi4 fl4;
__be32 daddr;
struct rtable *rt = skb_rtable(skb);

Expand All @@ -1478,20 +1481,16 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *ar
daddr = replyopts.opt.opt.faddr;
}

{
struct flowi4 fl4;

flowi4_init_output(&fl4, arg->bound_dev_if, 0,
RT_TOS(ip_hdr(skb)->tos),
RT_SCOPE_UNIVERSE, sk->sk_protocol,
ip_reply_arg_flowi_flags(arg),
daddr, rt->rt_spec_dst,
tcp_hdr(skb)->source, tcp_hdr(skb)->dest);
security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
rt = ip_route_output_key(sock_net(sk), &fl4);
if (IS_ERR(rt))
return;
}
flowi4_init_output(&fl4, arg->bound_dev_if, 0,
RT_TOS(ip_hdr(skb)->tos),
RT_SCOPE_UNIVERSE, sk->sk_protocol,
ip_reply_arg_flowi_flags(arg),
daddr, rt->rt_spec_dst,
tcp_hdr(skb)->source, tcp_hdr(skb)->dest);
security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
rt = ip_route_output_key(sock_net(sk), &fl4);
if (IS_ERR(rt))
return;

/* And let IP do all the hard work.
Expand All @@ -1512,7 +1511,7 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *ar
arg->csumoffset) = csum_fold(csum_add(skb->csum,
arg->csum));
skb->ip_summed = CHECKSUM_NONE;
ip_push_pending_frames(sk);
ip_push_pending_frames(sk, &fl4);
}

bh_unlock_sock(sk);
Expand Down
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