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| author | Maciej Żenczykowski <maze@google.com> | 2022-07-20 22:30:59 +0000 |
|---|---|---|
| committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | 2022-07-20 22:30:59 +0000 |
| commit | ca6312b6af2237edb421c282c6469777e5bc1390 (patch) | |
| tree | 13e706afe06f87ab77b6789fb29ddaf857748711 | |
| parent | a19a51e2583ce2406c0574888ca6d55c58354208 (diff) | |
| parent | a1cb0f30dec63d02154bf131d74816f467214cd4 (diff) | |
| download | android-clat-ca6312b6af2237edb421c282c6469777e5bc1390.tar.gz | |
randomized clat dad nonce, send only one copy am: a1cb0f30de
Original change: https://android-review.googlesource.com/c/platform/external/android-clat/+/2161296
Change-Id: I3dfe616c31ba1653cbc1aab920a5a1f619730096
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
| -rw-r--r-- | clatd.c | 14 |
1 files changed, 5 insertions, 9 deletions
@@ -138,7 +138,7 @@ void read_packet(int read_fd, int write_fd, int to_ipv6) { // u128 tgt_ip6 // ICMPv6 ND options: // u8 opt nr '14'; u8 length '1'; u8[6] nonce '6 random bytes' -void send_dad(int fd, const struct in6_addr* tgt, int count) { +void send_dad(int fd, const struct in6_addr* tgt) { struct { struct ip6_hdr ip6h; struct nd_neighbor_solicit ns; @@ -168,11 +168,9 @@ void send_dad(int fd, const struct in6_addr* tgt, int count) { }, .ns_opt_nr = 14, // icmp6 option 'nonce' from RFC3971 .ns_opt_len = 1, // in units of 8 bytes, including option nr and len - .ns_opt_nonce = { // 'opt_len' * 8 - [size of u8: opt nr] - [size of u8: opt len] = 6 bytes - 0, 0, 'C', 'L', 'A', 'T', - }, // first 2 bytes filled in below with random bytes, CLAT left to ease id in tcpdump + .ns_opt_nonce = {}, // opt_len *8 - sizeof u8(opt_nr) - sizeof u8(opt_len) = 6 ranodmized bytes }; - arc4random_buf(&dad_pkt.ns_opt_nonce, 2); + arc4random_buf(&dad_pkt.ns_opt_nonce, sizeof(dad_pkt.ns_opt_nonce)); // 40 byte IPv6 header + 8 byte ICMPv6 header + 16 byte ipv6 target address + 8 byte nonce option _Static_assert(sizeof(dad_pkt) == 40 + 8 + 16 + 8, "sizeof dad packet != 72"); @@ -198,9 +196,7 @@ void send_dad(int fd, const struct in6_addr* tgt, int count) { .sin6_scope_id = if_nametoindex(Global_Clatd_Config.native_ipv6_interface), }; - while (count--) { - sendto(fd, &dad_pkt, sizeof(dad_pkt), 0 /*flags*/, (const struct sockaddr *)&dst, sizeof(dst)); - } + sendto(fd, &dad_pkt, sizeof(dad_pkt), 0 /*flags*/, (const struct sockaddr *)&dst, sizeof(dst)); } /* function: event_loop @@ -217,7 +213,7 @@ void event_loop(struct tun_data *tunnel) { // (with the other 16 chosen to guarantee checksum neutrality) this seems like a remote // concern... // TODO: actually perform true DAD - send_dad(tunnel->write_fd6, &Global_Clatd_Config.ipv6_local_subnet, 2); + send_dad(tunnel->write_fd6, &Global_Clatd_Config.ipv6_local_subnet); time_t last_interface_poll; struct pollfd wait_fd[] = { |