From 70d43f9c0523a380a8451808b344c34685296725 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Tue, 16 Jan 2024 16:16:14 +1100 Subject: [PATCH] icmp: Share more between IPv4 and IPv6 paths in icmp_tap_handler() Currently icmp_tap_handler() consists of two almost disjoint paths for the IPv4 and IPv6 cases. The only thing they share is an error message. We can use some intermediate variables to refactor this to share some more code between those paths. Signed-off-by: David Gibson Signed-off-by: Stefano Brivio --- icmp.c | 144 ++++++++++++++++++++++++++++----------------------------- 1 file changed, 72 insertions(+), 72 deletions(-) diff --git a/icmp.c b/icmp.c index 757ca61..40edd55 100644 --- a/icmp.c +++ b/icmp.c @@ -154,102 +154,102 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, int af, const void *saddr, const void *daddr, const struct pool *p, const struct timespec *now) { + uint8_t proto = af == AF_INET ? IPPROTO_ICMP : IPPROTO_ICMPV6; + const char *const pname = af == AF_INET ? "ICMP" : "ICMPv6"; + union { + struct sockaddr sa; + struct sockaddr_in sa4; + struct sockaddr_in6 sa6; + } sa = { .sa.sa_family = af }; + const socklen_t sl = af == AF_INET ? sizeof(sa.sa4) : sizeof(sa.sa6); + struct icmp_id_sock *id_sock; + uint16_t id, seq; size_t plen; + void *pkt; + int s; (void)saddr; (void)pif; if (af == AF_INET) { - struct sockaddr_in sa = { - .sin_family = AF_INET, - }; - union icmp_epoll_ref iref; const struct icmphdr *ih; - int id, s; - ih = packet_get(p, 0, 0, sizeof(*ih), &plen); - if (!ih) + if (!(pkt = packet_get(p, 0, 0, sizeof(*ih), &plen))) return 1; + ih = (struct icmphdr *)pkt; + plen += sizeof(*ih); + if (ih->type != ICMP_ECHO) return 1; - iref.id = id = ntohs(ih->un.echo.id); - - if ((s = icmp_id_map[V4][id].sock) < 0) { - s = sock_l4(c, AF_INET, IPPROTO_ICMP, &c->ip4.addr_out, - c->ip4.ifname_out, 0, iref.u32); - if (s < 0) - goto fail_sock; - if (s > FD_REF_MAX) { - close(s); - return 1; - } - - icmp_id_map[V4][id].sock = s; - - debug("ICMP: new socket %i for echo ID %i", s, id); - } - icmp_id_map[V4][id].ts = now->tv_sec; - - sa.sin_addr = *(struct in_addr *)daddr; - if (sendto(s, ih, sizeof(*ih) + plen, MSG_NOSIGNAL, - (struct sockaddr *)&sa, sizeof(sa)) < 0) { - debug("ICMP: failed to relay request to socket"); - } else { - debug("ICMP: echo request to socket, ID: %i, seq: %i", - id, ntohs(ih->un.echo.sequence)); - } + id = ntohs(ih->un.echo.id); + id_sock = &icmp_id_map[V4][id]; + seq = ntohs(ih->un.echo.sequence); + sa.sa4.sin_addr = *(struct in_addr *)daddr; } else if (af == AF_INET6) { - struct sockaddr_in6 sa = { - .sin6_family = AF_INET6, - .sin6_scope_id = c->ifi6, - }; - union icmp_epoll_ref iref; const struct icmp6hdr *ih; - int id, s; - ih = packet_get(p, 0, 0, sizeof(struct icmp6hdr), &plen); - if (!ih) + if (!(pkt = packet_get(p, 0, 0, sizeof(*ih), &plen))) return 1; + ih = (struct icmp6hdr *)pkt; + plen += sizeof(*ih); + if (ih->icmp6_type != ICMPV6_ECHO_REQUEST) return 1; - iref.id = id = ntohs(ih->icmp6_identifier); - if ((s = icmp_id_map[V6][id].sock) < 0) { - s = sock_l4(c, AF_INET6, IPPROTO_ICMPV6, - &c->ip6.addr_out, - c->ip6.ifname_out, 0, iref.u32); - if (s < 0) - goto fail_sock; - if (s > FD_REF_MAX) { - close(s); - return 1; - } - - icmp_id_map[V6][id].sock = s; - - debug("ICMPv6: new socket %i for echo ID %i", s, id); - } - icmp_id_map[V6][id].ts = now->tv_sec; - - sa.sin6_addr = *(struct in6_addr *)daddr; - if (sendto(s, ih, sizeof(*ih) + plen, MSG_NOSIGNAL, - (struct sockaddr *)&sa, sizeof(sa)) < 1) { - debug("ICMPv6: failed to relay request to socket"); - } else { - debug("ICMPv6: echo request to socket, ID: %i, seq: %i", - id, ntohs(ih->icmp6_sequence)); - } + id = ntohs(ih->icmp6_identifier); + id_sock = &icmp_id_map[V6][id]; + seq = ntohs(ih->icmp6_sequence); + sa.sa6.sin6_addr = *(struct in6_addr *)daddr; + sa.sa6.sin6_scope_id = c->ifi6; + } else { + ASSERT(0); } - return 1; + if ((s = id_sock->sock) < 0) { + union icmp_epoll_ref iref = { .id = id }; + const void *bind_addr; + const char *bind_if; + + if (af == AF_INET) { + bind_addr = &c->ip4.addr_out; + bind_if = c->ip4.ifname_out; + } else { + bind_addr = &c->ip6.addr_out; + bind_if = c->ip6.ifname_out; + } + + s = sock_l4(c, af, proto, bind_addr, bind_if, 0, iref.u32); + + if (s < 0) { + warn("Cannot open \"ping\" socket. You might need to:"); + warn(" sysctl -w net.ipv4.ping_group_range=\"0 2147483647\""); + warn("...echo requests/replies will fail."); + return 1; + } + + if (s > FD_REF_MAX) { + close(s); + return 1; + } + + id_sock->sock = s; + + debug("%s: new socket %i for echo ID %"PRIu16, pname, s, id); + } + + id_sock->ts = now->tv_sec; + + if (sendto(s, pkt, plen, MSG_NOSIGNAL, &sa.sa, sl) < 0) { + debug("%s: failed to relay request to socket: %s", + pname, strerror(errno)); + } else { + debug("%s: echo request to socket, ID: %"PRIu16", seq: %"PRIu16, + pname, id, seq); + } -fail_sock: - warn("Cannot open \"ping\" socket. You might need to:"); - warn(" sysctl -w net.ipv4.ping_group_range=\"0 2147483647\""); - warn("...echo requests/replies will fail."); return 1; }