icmp: Look up ping flows using flow hash

When we receive a ping packet from the tap interface, we currently locate
the correct flow entry (if present) using an anciliary data structure, the
icmp_id_map[] tables.  However, we can look this up using the flow hash
table - that's what it's for.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
David Gibson 2024-07-18 15:26:39 +10:00 committed by Stefano Brivio
parent 6d76278c21
commit 2f40a01944

18
icmp.c
View file

@ -157,6 +157,7 @@ static void icmp_ping_close(const struct ctx *c,
epoll_ctl(c->epollfd, EPOLL_CTL_DEL, pingf->sock, NULL);
close(pingf->sock);
flow_hash_remove(c, FLOW_SIDX(pingf, INISIDE));
if (pingf->f.type == FLOW_PING4)
icmp_id_map[V4][id] = NULL;
@ -221,6 +222,7 @@ static struct icmp_ping_flow *icmp_ping_new(const struct ctx *c,
flow_dbg(pingf, "new socket %i for echo ID %"PRIu16, pingf->sock, id);
flow_hash_insert(c, FLOW_SIDX(pingf, INISIDE));
*id_sock = pingf;
FLOW_ACTIVATE(pingf);
@ -253,6 +255,8 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
union sockaddr_inany sa;
size_t dlen, l4len;
uint16_t id, seq;
union flow *flow;
uint8_t proto;
socklen_t sl;
void *pkt;
@ -271,6 +275,7 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
if (ih->type != ICMP_ECHO)
return 1;
proto = IPPROTO_ICMP;
id = ntohs(ih->un.echo.id);
id_sock = &icmp_id_map[V4][id];
seq = ntohs(ih->un.echo.sequence);
@ -286,6 +291,7 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
if (ih->icmp6_type != ICMPV6_ECHO_REQUEST)
return 1;
proto = IPPROTO_ICMPV6;
id = ntohs(ih->icmp6_identifier);
id_sock = &icmp_id_map[V6][id];
seq = ntohs(ih->icmp6_sequence);
@ -293,11 +299,17 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
ASSERT(0);
}
if (!(pingf = *id_sock))
if (!(pingf = icmp_ping_new(c, id_sock, af, id, saddr, daddr)))
return 1;
flow = flow_at_sidx(flow_lookup_af(c, proto, PIF_TAP,
af, saddr, daddr, id, id));
if (flow)
pingf = &flow->ping;
else if (!(pingf = icmp_ping_new(c, id_sock, af, id, saddr, daddr)))
return 1;
tgt = &pingf->f.side[TGTSIDE];
ASSERT(flow_proto[pingf->f.type] == proto);
pingf->ts = now->tv_sec;
pif_sockaddr(c, &sa, &sl, PIF_HOST, &tgt->eaddr, 0);