diff options
Diffstat (limited to 'clatd.c')
| -rw-r--r-- | clatd.c | 66 |
1 files changed, 65 insertions, 1 deletions
@@ -29,6 +29,15 @@ #include <arpa/inet.h> #include <fcntl.h> +#include <netinet/in.h> +#include <netinet/ip.h> +#include <netinet/ip_icmp.h> +#include <netinet/udp.h> +#include <netinet/tcp.h> +#include <netinet/ip6.h> +#include <netinet/icmp6.h> +#include <linux/icmp.h> + #include <sys/capability.h> #include <sys/uio.h> #include <linux/prctl.h> @@ -54,6 +63,11 @@ int forwarding_fd = -1; volatile sig_atomic_t running = 1; +struct tun_data { + char device6[IFNAMSIZ], device4[IFNAMSIZ]; + int fd6, fd4; +}; + /* function: set_forwarding * enables/disables ipv6 forwarding */ @@ -291,6 +305,56 @@ void configure_interface(const char *uplink_interface, const char *plat_prefix, configure_tun_ip(tunnel); } +/* function: packet_handler + * takes a tun header and a packet and sends it down the stack + * tunnel - tun device data + * tun_header - tun header + * packet - packet + * packetsize - size of packet + */ +void packet_handler(const struct tun_data *tunnel, struct tun_pi *tun_header, const char *packet, + size_t packetsize) { + int fd; + int iov_len = 0; + + // Allocate buffers for all packet headers. + struct tun_pi tun_targ; + char iphdr[sizeof(struct ip6_hdr)]; + char transporthdr[MAX_TCP_HDR]; + char icmp_iphdr[sizeof(struct ip6_hdr)]; + char icmp_transporthdr[MAX_TCP_HDR]; + + // iovec of the packets we'll send. This gets passed down to the translation functions. + clat_packet out = { + { &tun_targ, sizeof(tun_targ) }, // Tunnel header. + { iphdr, 0 }, // IP header. + { transporthdr, 0 }, // Transport layer header. + { icmp_iphdr, 0 }, // ICMP error inner IP header. + { icmp_transporthdr, 0 }, // ICMP error transport layer header. + { NULL, 0 }, // Payload. No buffer, it's a pointer to the original payload. + }; + + if(tun_header->flags != 0) { + logmsg(ANDROID_LOG_WARN,"packet_handler: unexpected flags = %d", tun_header->flags); + } + + if(ntohs(tun_header->proto) == ETH_P_IP) { + fd = tunnel->fd6; + fill_tun_header(&tun_targ, ETH_P_IPV6); + iov_len = ipv4_packet(out, CLAT_POS_IPHDR, packet, packetsize); + } else if(ntohs(tun_header->proto) == ETH_P_IPV6) { + fd = tunnel->fd4; + fill_tun_header(&tun_targ, ETH_P_IP); + iov_len = ipv6_packet(out, CLAT_POS_IPHDR, packet, packetsize); + } else { + logmsg(ANDROID_LOG_WARN,"packet_handler: unknown packet type = %x",tun_header->proto); + } + + if (iov_len > 0) { + writev(fd, out, iov_len); + } +} + /* function: read_packet * reads a packet from the tunnel fd and passes it down the stack * active_fd - tun file descriptor marked ready for reading @@ -319,7 +383,7 @@ void read_packet(int active_fd, const struct tun_data *tunnel) { return; } - translate_packet(tunnel, (struct tun_pi *) packet, packet + header_size, readlen - header_size); + packet_handler(tunnel, (struct tun_pi *) packet, packet + header_size, readlen - header_size); } } |