From 285baccfea46aa61e4ed4777da23105ccf19218b Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 17 Dec 2020 12:36:38 +0100 Subject: src: disallow burst 0 in ratelimits The ratelimiter in nftables is similar to the one in iptables, and iptables disallows a zero burst. Update the byte rate limiter not to print burst 5 (default value). Update tests/py payloads to print burst 5 instead of zero when the burst is unspecified. Signed-off-by: Pablo Neira Ayuso --- doc/statements.txt | 3 ++- src/parser_bison.y | 25 +++++++++++++++++++++++-- src/statement.c | 2 +- tests/py/any/limit.t.payload | 44 ++++++++++++++++++++++---------------------- 4 files changed, 48 insertions(+), 26 deletions(-) diff --git a/doc/statements.txt b/doc/statements.txt index beebba16..aac7c7d6 100644 --- a/doc/statements.txt +++ b/doc/statements.txt @@ -324,7 +324,8 @@ ____ A limit statement matches at a limited rate using a token bucket filter. A rule using this statement will match until this limit is reached. It can be used in combination with the log statement to give limited logging. The optional -*over* keyword makes it match over the specified rate. +*over* keyword makes it match over the specified rate. Default *burst* is 5. +if you specify *burst*, it must be non-zero value. .limit statement values [options="header"] diff --git a/src/parser_bison.y b/src/parser_bison.y index 4d4d2038..519e8efe 100644 --- a/src/parser_bison.y +++ b/src/parser_bison.y @@ -3038,6 +3038,11 @@ log_flag_tcp : SEQUENCE limit_stmt : LIMIT RATE limit_mode NUM SLASH time_unit limit_burst_pkts { + if ($7 == 0) { + erec_queue(error(&@7, "limit burst must be > 0"), + state->msgs); + YYERROR; + } $$ = limit_stmt_alloc(&@$); $$->limit.rate = $4; $$->limit.unit = $6; @@ -3050,6 +3055,12 @@ limit_stmt : LIMIT RATE limit_mode NUM SLASH time_unit limit_burst_pkts struct error_record *erec; uint64_t rate, unit; + if ($6 == 0) { + erec_queue(error(&@6, "limit burst must be > 0"), + state->msgs); + YYERROR; + } + erec = rate_parse(&@$, $5, &rate, &unit); xfree($5); if (erec != NULL) { @@ -3126,11 +3137,11 @@ limit_mode : OVER { $$ = NFT_LIMIT_F_INV; } | /* empty */ { $$ = 0; } ; -limit_burst_pkts : /* empty */ { $$ = 0; } +limit_burst_pkts : /* empty */ { $$ = 5; } | BURST NUM PACKETS { $$ = $2; } ; -limit_burst_bytes : /* empty */ { $$ = 0; } +limit_burst_bytes : /* empty */ { $$ = 5; } | BURST NUM BYTES { $$ = $2; } | BURST NUM STRING { @@ -4122,6 +4133,11 @@ set_elem_stmt : COUNTER } | LIMIT RATE limit_mode NUM SLASH time_unit limit_burst_pkts { + if ($7 == 0) { + erec_queue(error(&@7, "limit burst must be > 0"), + state->msgs); + YYERROR; + } $$ = limit_stmt_alloc(&@$); $$->limit.rate = $4; $$->limit.unit = $6; @@ -4134,6 +4150,11 @@ set_elem_stmt : COUNTER struct error_record *erec; uint64_t rate, unit; + if ($6 == 0) { + erec_queue(error(&@6, "limit burst must be > 0"), + state->msgs); + YYERROR; + } erec = rate_parse(&@$, $5, &rate, &unit); xfree($5); if (erec != NULL) { diff --git a/src/statement.c b/src/statement.c index 39020857..f7f1c0c4 100644 --- a/src/statement.c +++ b/src/statement.c @@ -464,7 +464,7 @@ static void limit_stmt_print(const struct stmt *stmt, struct output_ctx *octx) nft_print(octx, "limit rate %s%" PRIu64 " %s/%s", inv ? "over " : "", rate, data_unit, get_unit(stmt->limit.unit)); - if (stmt->limit.burst > 0) { + if (stmt->limit.burst != 5) { uint64_t burst; data_unit = get_rate(stmt->limit.burst, &burst); diff --git a/tests/py/any/limit.t.payload b/tests/py/any/limit.t.payload index b0cc84b4..dc6cea9b 100644 --- a/tests/py/any/limit.t.payload +++ b/tests/py/any/limit.t.payload @@ -1,22 +1,22 @@ # limit rate 400/minute ip test-ip4 output - [ limit rate 400/minute burst 0 type packets flags 0x0 ] + [ limit rate 400/minute burst 5 type packets flags 0x0 ] # limit rate 20/second ip test-ip4 output - [ limit rate 20/second burst 0 type packets flags 0x0 ] + [ limit rate 20/second burst 5 type packets flags 0x0 ] # limit rate 400/hour ip test-ip4 output - [ limit rate 400/hour burst 0 type packets flags 0x0 ] + [ limit rate 400/hour burst 5 type packets flags 0x0 ] # limit rate 400/week ip test-ip4 output - [ limit rate 400/week burst 0 type packets flags 0x0 ] + [ limit rate 400/week burst 5 type packets flags 0x0 ] # limit rate 40/day ip test-ip4 output - [ limit rate 40/day burst 0 type packets flags 0x0 ] + [ limit rate 40/day burst 5 type packets flags 0x0 ] # limit rate 1023/second burst 10 packets ip test-ip4 output @@ -24,27 +24,27 @@ ip test-ip4 output # limit rate 1 kbytes/second ip test-ip4 output - [ limit rate 1024/second burst 0 type bytes flags 0x0 ] + [ limit rate 1024/second burst 5 type bytes flags 0x0 ] # limit rate 2 kbytes/second ip test-ip4 output - [ limit rate 2048/second burst 0 type bytes flags 0x0 ] + [ limit rate 2048/second burst 5 type bytes flags 0x0 ] # limit rate 1025 kbytes/second ip test-ip4 output - [ limit rate 1049600/second burst 0 type bytes flags 0x0 ] + [ limit rate 1049600/second burst 5 type bytes flags 0x0 ] # limit rate 1023 mbytes/second ip test-ip4 output - [ limit rate 1072693248/second burst 0 type bytes flags 0x0 ] + [ limit rate 1072693248/second burst 5 type bytes flags 0x0 ] # limit rate 10230 mbytes/second ip test-ip4 output - [ limit rate 10726932480/second burst 0 type bytes flags 0x0 ] + [ limit rate 10726932480/second burst 5 type bytes flags 0x0 ] # limit rate 1023000 mbytes/second ip test-ip4 output - [ limit rate 1072693248000/second burst 0 type bytes flags 0x0 ] + [ limit rate 1072693248000/second burst 5 type bytes flags 0x0 ] # limit rate 1025 bytes/second burst 512 bytes ip test-ip4 output @@ -64,23 +64,23 @@ ip test-ip4 output # limit rate over 400/minute ip test-ip4 output - [ limit rate 400/minute burst 0 type packets flags 0x1 ] + [ limit rate 400/minute burst 5 type packets flags 0x1 ] # limit rate over 20/second ip test-ip4 output - [ limit rate 20/second burst 0 type packets flags 0x1 ] + [ limit rate 20/second burst 5 type packets flags 0x1 ] # limit rate over 400/hour ip test-ip4 output - [ limit rate 400/hour burst 0 type packets flags 0x1 ] + [ limit rate 400/hour burst 5 type packets flags 0x1 ] # limit rate over 400/week ip test-ip4 output - [ limit rate 400/week burst 0 type packets flags 0x1 ] + [ limit rate 400/week burst 5 type packets flags 0x1 ] # limit rate over 40/day ip test-ip4 output - [ limit rate 40/day burst 0 type packets flags 0x1 ] + [ limit rate 40/day burst 5 type packets flags 0x1 ] # limit rate over 1023/second burst 10 packets ip test-ip4 output @@ -88,27 +88,27 @@ ip test-ip4 output # limit rate over 1 kbytes/second ip test-ip4 output - [ limit rate 1024/second burst 0 type bytes flags 0x1 ] + [ limit rate 1024/second burst 5 type bytes flags 0x1 ] # limit rate over 2 kbytes/second ip test-ip4 output - [ limit rate 2048/second burst 0 type bytes flags 0x1 ] + [ limit rate 2048/second burst 5 type bytes flags 0x1 ] # limit rate over 1025 kbytes/second ip test-ip4 output - [ limit rate 1049600/second burst 0 type bytes flags 0x1 ] + [ limit rate 1049600/second burst 5 type bytes flags 0x1 ] # limit rate over 1023 mbytes/second ip test-ip4 output - [ limit rate 1072693248/second burst 0 type bytes flags 0x1 ] + [ limit rate 1072693248/second burst 5 type bytes flags 0x1 ] # limit rate over 10230 mbytes/second ip test-ip4 output - [ limit rate 10726932480/second burst 0 type bytes flags 0x1 ] + [ limit rate 10726932480/second burst 5 type bytes flags 0x1 ] # limit rate over 1023000 mbytes/second ip test-ip4 output - [ limit rate 1072693248000/second burst 0 type bytes flags 0x1 ] + [ limit rate 1072693248000/second burst 5 type bytes flags 0x1 ] # limit rate over 1025 bytes/second burst 512 bytes ip test-ip4 output -- cgit v1.2.3