From 7cbf364a5f68ba008c5e0702266fe3dc606b1d6f Mon Sep 17 00:00:00 2001 From: Kamal Heib Date: Thu, 9 Nov 2017 04:44:32 -0500 Subject: [PATCH] tc: flower: add support for tcp flags Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1456539 commit 0c30d14d0a2fc2fb6b7fef62bea05f2e5c3eb26a Author: Jiri Pirko Date: Tue May 23 23:51:39 2017 +0200 tc: flower: add support for tcp flags Allow user to insert a flower classifier filter rule which includes match for tcp flags. Signed-off-by: Jiri Pirko Signed-off-by: Kamal Heib --- man/man8/tc-flower.8 | 8 +++++++ tc/f_flower.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 70 insertions(+) diff --git a/man/man8/tc-flower.8 b/man/man8/tc-flower.8 index ba29065..7648079 100644 --- a/man/man8/tc-flower.8 +++ b/man/man8/tc-flower.8 @@ -35,6 +35,8 @@ flower \- flow based traffic control filter .IR PREFIX " | { " .BR dst_port " | " src_port " } " .IR port_number " } | " +.B tcp_flags +.IR MASKED_TCP_FLAGS " | " .B type .IR MASKED_TYPE " | " .B code @@ -136,6 +138,12 @@ Match on layer 4 protocol source or destination port number. Only available for .BR ip_proto " values " udp ", " tcp " and " sctp which have to be specified in beforehand. .TP +.BI tcp_flags " MASKED_TCP_FLAGS" +Match on TCP flags represented as 12bit bitfield in in hexadecimal format. +A mask may be optionally provided to limit the bits which are matched. A mask +is provided by following the value with a slash and then the mask. If the mask +is missing then a match on all bits is assumed. +.TP .BI type " MASKED_TYPE" .TQ .BI code " MASKED_CODE" diff --git a/tc/f_flower.c b/tc/f_flower.c index ebc63ca..1b6b46e 100644 --- a/tc/f_flower.c +++ b/tc/f_flower.c @@ -57,6 +57,7 @@ static void explain(void) " src_ip PREFIX |\n" " dst_port PORT-NUMBER |\n" " src_port PORT-NUMBER |\n" + " tcp_flags MASKED-TCP_FLAGS |\n" " type MASKED-ICMP-TYPE |\n" " code MASKED-ICMP-CODE |\n" " arp_tip IPV4-PREFIX |\n" @@ -474,6 +475,41 @@ static int flower_parse_port(char *str, __u8 ip_proto, return 0; } +#define TCP_FLAGS_MAX_MASK 0xfff + +static int flower_parse_tcp_flags(char *str, int flags_type, int mask_type, + struct nlmsghdr *n) +{ + char *slash; + int ret, err = -1; + __u16 flags; + + slash = strchr(str, '/'); + if (slash) + *slash = '\0'; + + ret = get_u16(&flags, str, 16); + if (ret < 0 || flags & ~TCP_FLAGS_MAX_MASK) + goto err; + + addattr16(n, MAX_MSG, flags_type, htons(flags)); + + if (slash) { + ret = get_u16(&flags, slash + 1, 16); + if (ret < 0 || flags & ~TCP_FLAGS_MAX_MASK) + goto err; + } else { + flags = TCP_FLAGS_MAX_MASK; + } + addattr16(n, MAX_MSG, mask_type, htons(flags)); + + err = 0; +err: + if (slash) + *slash = '/'; + return err; +} + static int flower_parse_key_id(const char *str, int type, struct nlmsghdr *n) { int ret; @@ -671,6 +707,16 @@ static int flower_parse_opt(struct filter_util *qu, char *handle, fprintf(stderr, "Illegal \"src_port\"\n"); return -1; } + } else if (matches(*argv, "tcp_flags") == 0) { + NEXT_ARG(); + ret = flower_parse_tcp_flags(*argv, + TCA_FLOWER_KEY_TCP_FLAGS, + TCA_FLOWER_KEY_TCP_FLAGS_MASK, + n); + if (ret < 0) { + fprintf(stderr, "Illegal \"tcp_flags\"\n"); + return -1; + } } else if (matches(*argv, "type") == 0) { NEXT_ARG(); ret = flower_parse_icmp(*argv, eth_type, ip_proto, @@ -1000,6 +1046,19 @@ static void flower_print_port(FILE *f, char *name, struct rtattr *attr) fprintf(f, "\n %s %d", name, rta_getattr_be16(attr)); } +static void flower_print_tcp_flags(FILE *f, char *name, + struct rtattr *flags_attr, + struct rtattr *mask_attr) +{ + if (!flags_attr) + return; + fprintf(f, "\n %s %x", name, rta_getattr_be16(flags_attr)); + if (!mask_attr) + return; + fprintf(f, "/%x", rta_getattr_be16(mask_attr)); +} + + static void flower_print_key_id(FILE *f, const char *name, struct rtattr *attr) { @@ -1110,6 +1169,9 @@ static int flower_print_opt(struct filter_util *qu, FILE *f, if (nl_type >= 0) flower_print_port(f, "src_port", tb[nl_type]); + flower_print_tcp_flags(f, "tcp_flags", tb[TCA_FLOWER_KEY_TCP_FLAGS], + tb[TCA_FLOWER_KEY_TCP_FLAGS_MASK]); + nl_type = flower_icmp_attr_type(eth_type, ip_proto, FLOWER_ICMP_FIELD_TYPE); nl_mask_type = flower_icmp_attr_mask_type(eth_type, ip_proto, -- 1.8.3.1