From 0ce0b0449082d4ad54d1714d8683d7a9276b3b93 Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Sat, 19 Oct 2013 17:37:09 +0200 Subject: Use the rsv2 field in the handshake header as an optional length field to facilitate future extensions --- src/handshake.c | 34 +++++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 11 deletions(-) (limited to 'src/handshake.c') diff --git a/src/handshake.c b/src/handshake.c index 47da0e4..82d47b8 100644 --- a/src/handshake.c +++ b/src/handshake.c @@ -98,10 +98,10 @@ fastd_buffer_t fastd_handshake_new_init(fastd_context_t *ctx, size_t tail_space) 4+method_list_len + /* supported method name list */ tail_space ); - fastd_handshake_packet_t *request = buffer.data; + fastd_handshake_packet_t *packet = buffer.data; - request->rsv1 = 0; - request->rsv2 = 0; + packet->rsv = 0; + packet->tlv_len = 0; fastd_handshake_add_uint8(ctx, &buffer, RECORD_HANDSHAKE_TYPE, 1); fastd_handshake_add_uint8(ctx, &buffer, RECORD_MODE, ctx->conf->mode); @@ -146,10 +146,10 @@ fastd_buffer_t fastd_handshake_new_reply(fastd_context_t *ctx, const fastd_hands extra_size + tail_space ); - fastd_handshake_packet_t *request = buffer.data; + fastd_handshake_packet_t *packet = buffer.data; - request->rsv1 = 0; - request->rsv2 = 0; + packet->rsv = 0; + packet->tlv_len = 0; fastd_handshake_add_uint8(ctx, &buffer, RECORD_HANDSHAKE_TYPE, AS_UINT8(handshake->records[RECORD_HANDSHAKE_TYPE])+1); fastd_handshake_add_uint8(ctx, &buffer, RECORD_REPLY_CODE, 0); @@ -186,15 +186,27 @@ void fastd_handshake_handle(fastd_context_t *ctx, fastd_socket_t *sock, const fa fastd_handshake_t handshake = { .buffer = buffer }; fastd_handshake_packet_t *packet = buffer.data; - uint8_t *ptr = packet->tlv_data; + size_t len = buffer.len - sizeof(fastd_handshake_packet_t); + if (packet->tlv_len) { + size_t tlv_len = ntohs(packet->tlv_len); + if (tlv_len > len) { + pr_warn(ctx, "received a short handshake from %I", remote_addr); + goto end_free; + } + + len = tlv_len; + } + + uint8_t *ptr = packet->tlv_data, *end = packet->tlv_data + len; + while (true) { - if (ptr+4 > (uint8_t*)buffer.data + buffer.len) + if (ptr+4 > end) break; uint16_t type = ptr[0] + (ptr[1] << 8); uint16_t len = ptr[2] + (ptr[3] << 8); - if (ptr+4+len > (uint8_t*)buffer.data + buffer.len) + if (ptr+4+len > end) break; if (type < RECORD_MAX) { @@ -292,8 +304,8 @@ void fastd_handshake_handle(fastd_context_t *ctx, fastd_socket_t *sock, const fa fastd_buffer_t reply_buffer = fastd_buffer_alloc(ctx, sizeof(fastd_handshake_packet_t), 0, 3*5 /* enough space for handshake type, reply code and error detail */); fastd_handshake_packet_t *reply = reply_buffer.data; - reply->rsv1 = 0; - reply->rsv2 = 0; + reply->rsv = 0; + reply->tlv_len = 0; fastd_handshake_add_uint8(ctx, &reply_buffer, RECORD_HANDSHAKE_TYPE, 2); fastd_handshake_add_uint8(ctx, &reply_buffer, RECORD_REPLY_CODE, reply_code); -- cgit v1.2.3