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nftables/SOURCES/0053-tcpopt-allow-to-check-for-presence-of-any-tcp-option.patch

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import nftables-0.9.3-21.el8
2021-08-24 22:33:58 +00:00
From 8a4b6cbf58e965d67b0337ba1736bd3691a49890 Mon Sep 17 00:00:00 2001
From: Phil Sutter <psutter@redhat.com>
Date: Mon, 12 Jul 2021 17:44:08 +0200
Subject: [PATCH] tcpopt: allow to check for presence of any tcp option
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1979334
Upstream Status: nftables commit 24d8da3083422
commit 24d8da3083422da8336eeed2ee23b2ccf598ba5a
Author: Florian Westphal <fw@strlen.de>
Date: Wed Oct 21 23:54:17 2020 +0200
tcpopt: allow to check for presence of any tcp option
nft currently doesn't allow to check for presence of arbitrary tcp options.
Only known options where nft provides a template can be tested for.
This allows to test for presence of raw protocol values as well.
Example:
tcp option 42 exists
Signed-off-by: Florian Westphal <fw@strlen.de>
---
include/expression.h | 3 +-
src/exthdr.c | 12 ++++++++
src/ipopt.c | 1 +
src/netlink_linearize.c | 2 +-
src/parser_bison.y | 7 +++++
src/tcpopt.c | 42 +++++++++++++++++++++++----
tests/py/any/tcpopt.t | 2 ++
tests/py/any/tcpopt.t.payload | 53 +++--------------------------------
8 files changed, 65 insertions(+), 57 deletions(-)
diff --git a/include/expression.h b/include/expression.h
index 2e41aa0..b50183d 100644
--- a/include/expression.h
+++ b/include/expression.h
@@ -299,7 +299,8 @@ struct expr {
/* EXPR_EXTHDR */
const struct exthdr_desc *desc;
const struct proto_hdr_template *tmpl;
- unsigned int offset;
+ uint16_t offset;
+ uint8_t raw_type;
enum nft_exthdr_op op;
unsigned int flags;
} exthdr;
diff --git a/src/exthdr.c b/src/exthdr.c
index c28213f..68d5aa5 100644
--- a/src/exthdr.c
+++ b/src/exthdr.c
@@ -32,6 +32,13 @@ static void exthdr_expr_print(const struct expr *expr, struct output_ctx *octx)
*/
unsigned int offset = expr->exthdr.offset / 64;
+ if (expr->exthdr.desc == NULL &&
+ expr->exthdr.offset == 0 &&
+ expr->exthdr.flags & NFT_EXTHDR_F_PRESENT) {
+ nft_print(octx, "tcp option %d", expr->exthdr.raw_type);
+ return;
+ }
+
nft_print(octx, "tcp option %s", expr->exthdr.desc->name);
if (expr->exthdr.flags & NFT_EXTHDR_F_PRESENT)
return;
@@ -59,6 +66,7 @@ static bool exthdr_expr_cmp(const struct expr *e1, const struct expr *e2)
return e1->exthdr.desc == e2->exthdr.desc &&
e1->exthdr.tmpl == e2->exthdr.tmpl &&
e1->exthdr.op == e2->exthdr.op &&
+ e1->exthdr.raw_type == e2->exthdr.raw_type &&
e1->exthdr.flags == e2->exthdr.flags;
}
@@ -69,6 +77,7 @@ static void exthdr_expr_clone(struct expr *new, const struct expr *expr)
new->exthdr.offset = expr->exthdr.offset;
new->exthdr.op = expr->exthdr.op;
new->exthdr.flags = expr->exthdr.flags;
+ new->exthdr.raw_type = expr->exthdr.raw_type;
}
const struct expr_ops exthdr_expr_ops = {
@@ -98,6 +107,7 @@ struct expr *exthdr_expr_alloc(const struct location *loc,
expr = expr_alloc(loc, EXPR_EXTHDR, tmpl->dtype,
BYTEORDER_BIG_ENDIAN, tmpl->len);
expr->exthdr.desc = desc;
+ expr->exthdr.raw_type = desc ? desc->type : 0;
expr->exthdr.tmpl = tmpl;
expr->exthdr.offset = tmpl->offset;
return expr;
@@ -176,6 +186,8 @@ void exthdr_init_raw(struct expr *expr, uint8_t type,
unsigned int i;
assert(expr->etype == EXPR_EXTHDR);
+ expr->exthdr.raw_type = type;
+
if (op == NFT_EXTHDR_OP_TCPOPT)
return tcpopt_init_raw(expr, type, offset, len, flags);
if (op == NFT_EXTHDR_OP_IPV4)
diff --git a/src/ipopt.c b/src/ipopt.c
index 7ecb8b9..5f9f908 100644
--- a/src/ipopt.c
+++ b/src/ipopt.c
@@ -103,6 +103,7 @@ struct expr *ipopt_expr_alloc(const struct location *loc, uint8_t type,
expr->exthdr.tmpl = tmpl;
expr->exthdr.op = NFT_EXTHDR_OP_IPV4;
expr->exthdr.offset = tmpl->offset + calc_offset(desc, tmpl, ptr);
+ expr->exthdr.raw_type = desc->type;
return expr;
}
diff --git a/src/netlink_linearize.c b/src/netlink_linearize.c
index 9d1a064..28b0e6a 100644
--- a/src/netlink_linearize.c
+++ b/src/netlink_linearize.c
@@ -174,7 +174,7 @@ static void netlink_gen_exthdr(struct netlink_linearize_ctx *ctx,
nle = alloc_nft_expr("exthdr");
netlink_put_register(nle, NFTNL_EXPR_EXTHDR_DREG, dreg);
nftnl_expr_set_u8(nle, NFTNL_EXPR_EXTHDR_TYPE,
- expr->exthdr.desc->type);
+ expr->exthdr.raw_type);
nftnl_expr_set_u32(nle, NFTNL_EXPR_EXTHDR_OFFSET, offset / BITS_PER_BYTE);
nftnl_expr_set_u32(nle, NFTNL_EXPR_EXTHDR_LEN,
div_round_up(expr->len, BITS_PER_BYTE));
diff --git a/src/parser_bison.y b/src/parser_bison.y
index 114b289..4ea9364 100644
--- a/src/parser_bison.y
+++ b/src/parser_bison.y
@@ -4744,6 +4744,13 @@ tcp_hdr_option_type : EOL { $$ = TCPOPT_KIND_EOL; }
| SACK3 { $$ = TCPOPT_KIND_SACK3; }
| ECHO { $$ = TCPOPT_KIND_ECHO; }
| TIMESTAMP { $$ = TCPOPT_KIND_TIMESTAMP; }
+ | NUM {
+ if ($1 > 255) {
+ erec_queue(error(&@1, "value too large"), state->msgs);
+ YYERROR;
+ }
+ $$ = $1;
+ }
;
tcp_hdr_option_field : KIND { $$ = TCPOPT_COMMON_KIND; }
diff --git a/src/tcpopt.c b/src/tcpopt.c
index d1dd13b..1cf97a5 100644
--- a/src/tcpopt.c
+++ b/src/tcpopt.c
@@ -103,6 +103,19 @@ const struct exthdr_desc *tcpopt_protocols[] = {
[TCPOPT_KIND_TIMESTAMP] = &tcpopt_timestamp,
};
+/**
+ * tcpopt_expr_alloc - allocate tcp option extension expression
+ *
+ * @loc: location from parser
+ * @kind: raw tcp option value to find in packet
+ * @field: highlevel field to find in the option if @kind is present in packet
+ *
+ * Allocate a new tcp option expression.
+ * @kind is the raw option value to find in the packet.
+ * Exception: SACK may use extra OOB data that is mangled here.
+ *
+ * @field is the optional field to extract from the @type option.
+ */
struct expr *tcpopt_expr_alloc(const struct location *loc,
unsigned int kind,
unsigned int field)
@@ -138,8 +151,22 @@ struct expr *tcpopt_expr_alloc(const struct location *loc,
if (kind < array_size(tcpopt_protocols))
desc = tcpopt_protocols[kind];
- if (!desc)
- return NULL;
+ if (!desc) {
+ if (field != TCPOPT_COMMON_KIND || kind > 255)
+ return NULL;
+
+ expr = expr_alloc(loc, EXPR_EXTHDR, &integer_type,
+ BYTEORDER_BIG_ENDIAN, 8);
+
+ desc = tcpopt_protocols[TCPOPT_NOP];
+ tmpl = &desc->templates[field];
+ expr->exthdr.desc = desc;
+ expr->exthdr.tmpl = tmpl;
+ expr->exthdr.op = NFT_EXTHDR_OP_TCPOPT;
+ expr->exthdr.raw_type = kind;
+ return expr;
+ }
+
tmpl = &desc->templates[field];
if (!tmpl)
return NULL;
@@ -149,6 +176,7 @@ struct expr *tcpopt_expr_alloc(const struct location *loc,
expr->exthdr.desc = desc;
expr->exthdr.tmpl = tmpl;
expr->exthdr.op = NFT_EXTHDR_OP_TCPOPT;
+ expr->exthdr.raw_type = desc->type;
expr->exthdr.offset = tmpl->offset;
return expr;
@@ -165,6 +193,10 @@ void tcpopt_init_raw(struct expr *expr, uint8_t type, unsigned int off,
expr->len = len;
expr->exthdr.flags = flags;
expr->exthdr.offset = off;
+ expr->exthdr.op = NFT_EXTHDR_OP_TCPOPT;
+
+ if (flags & NFT_EXTHDR_F_PRESENT)
+ datatype_set(expr, &boolean_type);
if (type >= array_size(tcpopt_protocols))
return;
@@ -178,12 +210,10 @@ void tcpopt_init_raw(struct expr *expr, uint8_t type, unsigned int off,
if (tmpl->offset != off || tmpl->len != len)
continue;
- if (flags & NFT_EXTHDR_F_PRESENT)
- datatype_set(expr, &boolean_type);
- else
+ if ((flags & NFT_EXTHDR_F_PRESENT) == 0)
datatype_set(expr, tmpl->dtype);
+
expr->exthdr.tmpl = tmpl;
- expr->exthdr.op = NFT_EXTHDR_OP_TCPOPT;
break;
}
}
diff --git a/tests/py/any/tcpopt.t b/tests/py/any/tcpopt.t
index 1d42de8..7b17014 100644
--- a/tests/py/any/tcpopt.t
+++ b/tests/py/any/tcpopt.t
@@ -30,6 +30,7 @@ tcp option timestamp kind 1;ok
tcp option timestamp length 1;ok
tcp option timestamp tsval 1;ok
tcp option timestamp tsecr 1;ok
+tcp option 255 missing;ok
tcp option foobar;fail
tcp option foo bar;fail
@@ -38,6 +39,7 @@ tcp option eol left 1;fail
tcp option eol left 1;fail
tcp option sack window;fail
tcp option sack window 1;fail
+tcp option 256 exists;fail
tcp option window exists;ok
tcp option window missing;ok
diff --git a/tests/py/any/tcpopt.t.payload b/tests/py/any/tcpopt.t.payload
index 9c480c8..34f8e26 100644
--- a/tests/py/any/tcpopt.t.payload
+++ b/tests/py/any/tcpopt.t.payload
@@ -509,20 +509,6 @@ inet
[ exthdr load tcpopt 4b @ 8 + 2 => reg 1 ]
[ cmp eq reg 1 0x01000000 ]
-# tcp option timestamp tsecr 1
-ip
- [ meta load l4proto => reg 1 ]
- [ cmp eq reg 1 0x00000006 ]
- [ exthdr load tcpopt 4b @ 8 + 6 => reg 1 ]
- [ cmp eq reg 1 0x01000000 ]
-
-# tcp option timestamp tsecr 1
-ip6
- [ meta load l4proto => reg 1 ]
- [ cmp eq reg 1 0x00000006 ]
- [ exthdr load tcpopt 4b @ 8 + 6 => reg 1 ]
- [ cmp eq reg 1 0x01000000 ]
-
# tcp option timestamp tsecr 1
inet
[ meta load l4proto => reg 1 ]
@@ -530,19 +516,12 @@ inet
[ exthdr load tcpopt 4b @ 8 + 6 => reg 1 ]
[ cmp eq reg 1 0x01000000 ]
-# tcp option window exists
-ip
- [ meta load l4proto => reg 1 ]
- [ cmp eq reg 1 0x00000006 ]
- [ exthdr load tcpopt 1b @ 3 + 0 present => reg 1 ]
- [ cmp eq reg 1 0x00000001 ]
-
-# tcp option window exists
-ip6
+# tcp option 255 missing
+inet
[ meta load l4proto => reg 1 ]
[ cmp eq reg 1 0x00000006 ]
- [ exthdr load tcpopt 1b @ 3 + 0 present => reg 1 ]
- [ cmp eq reg 1 0x00000001 ]
+ [ exthdr load tcpopt 1b @ 255 + 0 present => reg 1 ]
+ [ cmp eq reg 1 0x00000000 ]
# tcp option window exists
inet
@@ -551,20 +530,6 @@ inet
[ exthdr load tcpopt 1b @ 3 + 0 present => reg 1 ]
[ cmp eq reg 1 0x00000001 ]
-# tcp option window missing
-ip
- [ meta load l4proto => reg 1 ]
- [ cmp eq reg 1 0x00000006 ]
- [ exthdr load tcpopt 1b @ 3 + 0 present => reg 1 ]
- [ cmp eq reg 1 0x00000000 ]
-
-# tcp option window missing
-ip6
- [ meta load l4proto => reg 1 ]
- [ cmp eq reg 1 0x00000006 ]
- [ exthdr load tcpopt 1b @ 3 + 0 present => reg 1 ]
- [ cmp eq reg 1 0x00000000 ]
-
# tcp option window missing
inet
[ meta load l4proto => reg 1 ]
@@ -572,16 +537,6 @@ inet
[ exthdr load tcpopt 1b @ 3 + 0 present => reg 1 ]
[ cmp eq reg 1 0x00000000 ]
-# tcp option maxseg size set 1360
-ip
- [ immediate reg 1 0x00005005 ]
- [ exthdr write tcpopt reg 1 => 2b @ 2 + 2 ]
-
-# tcp option maxseg size set 1360
-ip6
- [ immediate reg 1 0x00005005 ]
- [ exthdr write tcpopt reg 1 => 2b @ 2 + 2 ]
-
# tcp option maxseg size set 1360
inet
[ immediate reg 1 0x00005005 ]
--
2.31.1
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