From d62b288697683b40cffed37fbc9761383be17e0c Mon Sep 17 00:00:00 2001
From: Michael Tuexen <tuexen@fh-muenster.de>
Date: Thu, 6 Jul 2017 08:53:14 +0200
Subject: [PATCH] Add support for absolute TCP sequence numbers.
Sponsored by: Netflix, Inc.
---
gtests/net/packetdrill/packet.h | 9 +++++----
gtests/net/packetdrill/parser.y | 23 ++++++++++++++++++++++-
gtests/net/packetdrill/run_packet.c | 17 +++++++++++------
gtests/net/packetdrill/tcp_packet.c | 4 ++++
gtests/net/packetdrill/tcp_packet.h | 1 +
5 files changed, 43 insertions(+), 11 deletions(-)
diff --git a/gtests/net/packetdrill/packet.h b/gtests/net/packetdrill/packet.h
index fa7416c2..3d7de771 100644
--- a/gtests/net/packetdrill/packet.h
+++ b/gtests/net/packetdrill/packet.h
@@ -109,10 +109,11 @@ struct packet {
#define FLAG_WIN_NOCHECK 0x1 /* don't check TCP receive window */
#define FLAG_OPTIONS_NOCHECK 0x2 /* don't check TCP options */
#define FLAG_ABSOLUTE_TS_ECR 0x4 /* don't adjust TCP TS ecr */
-#define FLAGS_SCTP_BAD_CRC32C 0x8 /* compute bad CRC32C for SCTP packets */
-#define FLAGS_SCTP_EXPLICIT_TAG 0x10 /* verification tag specified */
-#define FLAGS_SCTP_GENERIC_PACKET 0x20 /* set if it is a generic packet */
-#define FLAGS_UDP_ENCAPSULATED 0x40 /* TCP/UDP or SCTP/UDP encapsulated */
+#define FLAG_ABSOLUTE_SEQ 0x8 /* don't adjust TCP.SEQ */
+#define FLAGS_SCTP_BAD_CRC32C 0x10 /* compute bad CRC32C for SCTP packets */
+#define FLAGS_SCTP_EXPLICIT_TAG 0x20 /* verification tag specified */
+#define FLAGS_SCTP_GENERIC_PACKET 0x40 /* set if it is a generic packet */
+#define FLAGS_UDP_ENCAPSULATED 0x80 /* TCP/UDP or SCTP/UDP encapsulated */
enum ip_ecn_t ecn; /* IPv4/IPv6 ECN treatment for packet */
diff --git a/gtests/net/packetdrill/parser.y b/gtests/net/packetdrill/parser.y
index 399656cd..715bfd2b 100644
--- a/gtests/net/packetdrill/parser.y
+++ b/gtests/net/packetdrill/parser.y
@@ -460,6 +460,7 @@ static struct tcp_option *new_tcp_fast_open_option(const char *cookie_string,
struct {
u32 start_sequence;
u16 payload_bytes;
+ bool absolute;
} tcp_sequence_info;
struct {
int protocol;
@@ -2319,7 +2320,7 @@ sctp_protocol_violation_cause_spec
}
tcp_packet_spec
-: packet_prefix opt_ip_info flags seq opt_ack opt_window opt_tcp_options opt_udp_encaps_info{
+: packet_prefix opt_ip_info flags seq opt_ack opt_window opt_tcp_options opt_udp_encaps_info {
char *error = NULL;
struct packet *outer = $1, *inner = NULL;
enum direction_t direction = outer->direction;
@@ -2335,6 +2336,7 @@ tcp_packet_spec
$4.start_sequence, $4.payload_bytes,
$5, $6, $7,
absolute_ts_ecr,
+ $4.absolute,
$8.udp_src_port, $8.udp_dst_port,
&error);
absolute_ts_ecr = false;
@@ -2598,6 +2600,25 @@ seq
}
$$.start_sequence = $1;
$$.payload_bytes = $5;
+ $$.absolute = false;
+}
+| INTEGER ':' INTEGER '(' INTEGER ')' '!' {
+ if (!is_valid_u32($1)) {
+ semantic_error("TCP start sequence number out of range");
+ }
+ if (!is_valid_u32($3)) {
+ semantic_error("TCP end sequence number out of range");
+ }
+ if (!is_valid_u16($5)) {
+ semantic_error("TCP payload size out of range");
+ }
+ if ($3 != ($1 +$5)) {
+ semantic_error("inconsistent TCP sequence numbers and "
+ "payload size");
+ }
+ $$.start_sequence = $1;
+ $$.payload_bytes = $5;
+ $$.absolute = true;
}
;
diff --git a/gtests/net/packetdrill/run_packet.c b/gtests/net/packetdrill/run_packet.c
index 350bbe4a..3debc5d7 100644
--- a/gtests/net/packetdrill/run_packet.c
+++ b/gtests/net/packetdrill/run_packet.c
@@ -940,8 +940,10 @@ static int map_inbound_packet(
/* Remap the sequence number from script sequence number to live. */
const bool is_syn = live_packet->tcp->syn;
const u32 seq_offset = remote_seq_script_to_live_offset(socket, is_syn);
- live_packet->tcp->seq =
- htonl(ntohl(live_packet->tcp->seq) + seq_offset);
+ if ((live_packet->flags & FLAG_ABSOLUTE_SEQ) == 0) {
+ live_packet->tcp->seq =
+ htonl(ntohl(live_packet->tcp->seq) + seq_offset);
+ }
/* Remap the ACK and SACKs from script sequence number to live. */
const u32 ack_offset = local_seq_script_to_live_offset(socket, is_syn);
@@ -1188,9 +1190,12 @@ static int map_outbound_live_packet(
/* Rewrite TCP sequence number from live to script space. */
const bool is_syn = live_packet->tcp->syn;
const u32 seq_offset = local_seq_live_to_script_offset(socket, is_syn);
- actual_packet->tcp->seq =
- htonl(ntohl(live_packet->tcp->seq) + seq_offset);
-
+ if ((script_packet->flags & FLAG_ABSOLUTE_SEQ) == 0) {
+ actual_packet->tcp->seq =
+ htonl(ntohl(live_packet->tcp->seq) + seq_offset);
+ } else {
+ actual_packet->tcp->seq = live_packet->tcp->seq;
+ }
/* Rewrite ACKs and SACKs from live to script space. */
const u32 ack_offset = remote_seq_live_to_script_offset(socket, is_syn);
if (actual_packet->tcp->ack)
@@ -3522,7 +3527,7 @@ int reset_connection(struct state *state, struct socket *socket)
packet = new_tcp_packet(socket->address_family,
DIRECTION_INBOUND, ECN_NONE,
"R.", seq, 0, ack_seq, window, NULL, false,
- udp_src_port, udp_dst_port, &error);
+ false, udp_src_port, udp_dst_port, &error);
if (packet == NULL)
die("%s", error);
diff --git a/gtests/net/packetdrill/tcp_packet.c b/gtests/net/packetdrill/tcp_packet.c
index e83a8066..2bbe13f8 100644
--- a/gtests/net/packetdrill/tcp_packet.c
+++ b/gtests/net/packetdrill/tcp_packet.c
@@ -60,6 +60,7 @@ struct packet *new_tcp_packet(int address_family,
s32 window,
const struct tcp_options *tcp_options,
bool abs_ts_ecr,
+ bool abs_seq,
u16 udp_src_port,
u16 udp_dst_port,
char **error)
@@ -183,6 +184,9 @@ struct packet *new_tcp_packet(int address_family,
if (abs_ts_ecr) {
packet->flags |= FLAG_ABSOLUTE_TS_ECR;
}
+ if (abs_seq) {
+ packet->flags |= FLAG_ABSOLUTE_SEQ;
+ }
packet->ip_bytes = ip_bytes;
return packet;
diff --git a/gtests/net/packetdrill/tcp_packet.h b/gtests/net/packetdrill/tcp_packet.h
index 415445e9..deacd96f 100644
--- a/gtests/net/packetdrill/tcp_packet.h
+++ b/gtests/net/packetdrill/tcp_packet.h
@@ -45,6 +45,7 @@ extern struct packet *new_tcp_packet(int address_family,
s32 window,
const struct tcp_options *tcp_options,
bool abs_ts_ecr,
+ bool abs_seq,
u16 udp_src_port,
u16 udp_dst_port,
char **error);
--
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