diff options
Diffstat (limited to 'tap.c')
| -rw-r--r-- | tap.c | 82 |
1 files changed, 62 insertions, 20 deletions
@@ -175,21 +175,22 @@ void tap_ip4_send(const struct ctx *c, in_addr_t src, uint8_t proto, } /** - * tap_ip6_send() - Send IPv6 packet, with L2 headers, calculating L3/L4 checksums + * tap_push_ip6h() - Build IPv6 header for inbound packet * @c: Execution context * @src: IPv6 source address - * @proto: L4 protocol number - * @in: Payload + * @dst: IPv6 destination address * @len: L4 payload length - * @flow: Flow label + * @proto: L4 protocol number + * @flow: IPv6 flow identifier + * + * Return: pointer at which to write the packet's payload */ -void tap_ip6_send(const struct ctx *c, const struct in6_addr *src, - uint8_t proto, const char *in, size_t len, uint32_t flow) +static void *tap_push_ip6h(char *buf, + const struct in6_addr *src, + const struct in6_addr *dst, + size_t len, uint8_t proto, uint32_t flow) { - char buf[USHRT_MAX]; - struct ipv6hdr *ip6h = - (struct ipv6hdr *)tap_push_l2h(c, buf, ETH_P_IPV6); - char *data = (char *)(ip6h + 1); + struct ipv6hdr *ip6h = (struct ipv6hdr *)buf; ip6h->payload_len = htons(len); ip6h->priority = 0; @@ -197,24 +198,65 @@ void tap_ip6_send(const struct ctx *c, const struct in6_addr *src, ip6h->nexthdr = proto; ip6h->hop_limit = 255; ip6h->saddr = *src; - ip6h->daddr = *tap_ip6_daddr(c, src); + ip6h->daddr = *dst; ip6h->flow_lbl[0] = (flow >> 16) & 0xf; ip6h->flow_lbl[1] = (flow >> 8) & 0xff; ip6h->flow_lbl[2] = (flow >> 0) & 0xff; + return ip6h + 1; +} +/** + * tap_udp6_send() - Send UDP over IPv6 packet + * @c: Execution context + * @src: IPv6 source address + * @sport: UDP source port + * @dst: IPv6 destination address + * @dport: UDP destination port + * @flow: Flow label + * @in: UDP payload contents (not including UDP header) + * @len: UDP payload length (not including UDP header) + */ +void tap_udp6_send(const struct ctx *c, + const struct in6_addr *src, in_port_t sport, + const struct in6_addr *dst, in_port_t dport, + uint32_t flow, const void *in, size_t len) +{ + size_t udplen = len + sizeof(struct udphdr); + char buf[USHRT_MAX]; + void *ip6h = tap_push_l2h(c, buf, ETH_P_IPV6); + void *uhp = tap_push_ip6h(ip6h, src, dst, udplen, IPPROTO_UDP, flow); + struct udphdr *uh = (struct udphdr *)uhp; + char *data = (char *)(uh + 1); + + uh->source = htons(sport); + uh->dest = htons(dport); + uh->len = htons(udplen); + csum_udp6(uh, src, dst, in, len); memcpy(data, in, len); - if (proto == IPPROTO_UDP) { - struct udphdr *uh = (struct udphdr *)(ip6h + 1); + if (tap_send(c, buf, len + (data - buf)) < 1) + debug("tap: failed to send %lu bytes (IPv6)", len); +} - csum_udp6(uh, &ip6h->saddr, &ip6h->daddr, - uh + 1, len - sizeof(*uh)); - } else if (proto == IPPROTO_ICMPV6) { - struct icmp6hdr *ih = (struct icmp6hdr *)(ip6h + 1); +/** + * tap_icmp6_send() - Send ICMPv6 packet + * @c: Execution context + * @src: IPv6 source address + * @dst: IPv6 destination address + * @in: ICMP packet, including ICMP header + * @len: ICMP packet length, including ICMP header + */ +void tap_icmp6_send(const struct ctx *c, + const struct in6_addr *src, const struct in6_addr *dst, + void *in, size_t len) +{ + char buf[USHRT_MAX]; + void *ip6h = tap_push_l2h(c, buf, ETH_P_IPV6); + char *data = tap_push_ip6h(ip6h, src, dst, len, IPPROTO_ICMPV6, 0); + struct icmp6hdr *icmp6h = (struct icmp6hdr *)data; - csum_icmp6(ih, &ip6h->saddr, &ip6h->daddr, - ih + 1, len - sizeof(*ih)); - } + memcpy(data, in, len); + csum_icmp6(icmp6h, src, dst, icmp6h + 1, len - sizeof(*icmp6h)); if (tap_send(c, buf, len + (data - buf)) < 1) debug("tap: failed to send %lu bytes (IPv6)", len); |