Create a new action type for TC that allows the pushing, popping, and
modifying of MPLS headers.
Signed-off-by: John Hurley <john.hur...@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicin...@netronome.com>
---
tc/Makefile | 1 +
tc/m_mpls.c | 275 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 276 insertions(+)
create mode 100644 tc/m_mpls.c
diff --git a/tc/Makefile b/tc/Makefile
index 60abdde..09ff369 100644
--- a/tc/Makefile
+++ b/tc/Makefile
@@ -39,6 +39,7 @@ TCMODULES += q_drr.o
TCMODULES += q_qfq.o
TCMODULES += m_gact.o
TCMODULES += m_mirred.o
+TCMODULES += m_mpls.o
TCMODULES += m_nat.o
TCMODULES += m_pedit.o
TCMODULES += m_ife.o
diff --git a/tc/m_mpls.c b/tc/m_mpls.c
new file mode 100644
index 0000000..d2700ec
--- /dev/null
+++ b/tc/m_mpls.c
@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/* Copyright (C) 2019 Netronome Systems, Inc. */
+
+#include <linux/if_ether.h>
+#include <linux/tc_act/tc_mpls.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "utils.h"
+#include "rt_names.h"
+#include "tc_util.h"
+
+static const char * const action_names[] = {
+ [TCA_MPLS_ACT_POP] = "pop",
+ [TCA_MPLS_ACT_PUSH] = "push",
+ [TCA_MPLS_ACT_MODIFY] = "modify",
+ [TCA_MPLS_ACT_DEC_TTL] = "dec_ttl",
+};
+
+static void explain(void)
+{
+ fprintf(stderr,
+ "Usage: mpls pop [ protocol MPLS_PROTO ]\n"
+ " mpls push [ protocol MPLS_PROTO ] [ label MPLS_LABEL ]
[ tc MPLS_TC ] [ ttl MPLS_TTL ] [ bos MPLS_BOS ] [CONTROL]\n"
+ " mpls modify [ label MPLS_LABEL ] [ tc MPLS_TC ] [ ttl
MPLS_TTL ] [CONTROL]\n"
+ " for pop MPLS_PROTO is next header of packet - e.g. ip
or mpls_uc\n"
+ " for push MPLS_PROTO is one of mpls_uc or mpls_mc\n"
+ " with default: mpls_uc\n"
+ " CONTROL := reclassify | pipe | drop | continue | pass
|\n"
+ " goto chain <CHAIN_INDEX>\n");
+}
+
+static void usage(void)
+{
+ explain();
+ exit(-1);
+}
+
+static bool can_modify_mpls_fields(unsigned int action)
+{
+ return action == TCA_MPLS_ACT_PUSH || action == TCA_MPLS_ACT_MODIFY;
+}
+
+static bool can_modify_ethtype(unsigned int action)
+{
+ return action == TCA_MPLS_ACT_PUSH || action == TCA_MPLS_ACT_POP;
+}
+
+static bool is_valid_label(__u32 label)
+{
+ return label <= 0xfffff;
+}
+
+static bool check_double_action(unsigned int action, const char *arg)
+{
+ if (!action)
+ return false;
+
+ fprintf(stderr,
+ "Error: got \"%s\" but action already set to \"%s\"\n",
+ arg, action_names[action]);
+ explain();
+ return true;
+}
+
+static int parse_mpls(struct action_util *a, int *argc_p, char ***argv_p,
+ int tca_id, struct nlmsghdr *n)
+{
+ struct tc_mpls parm = {};
+ __u32 label = 0xffffffff;
+ unsigned int action = 0;
+ char **argv = *argv_p;
+ struct rtattr *tail;
+ int argc = *argc_p;
+ __u16 proto = 0;
+ __u8 bos = 0xff;
+ __u8 tc = 0xff;
+ __u8 ttl = 0;
+
+ if (matches(*argv, "mpls") != 0)
+ return -1;
+
+ NEXT_ARG();
+
+ while (argc > 0) {
+ if (matches(*argv, "pop") == 0) {
+ if (check_double_action(action, *argv))
+ return -1;
+ action = TCA_MPLS_ACT_POP;
+ } else if (matches(*argv, "push") == 0) {
+ if (check_double_action(action, *argv))
+ return -1;
+ action = TCA_MPLS_ACT_PUSH;
+ } else if (matches(*argv, "modify") == 0) {
+ if (check_double_action(action, *argv))
+ return -1;
+ action = TCA_MPLS_ACT_MODIFY;
+ } else if (matches(*argv, "dec_ttl") == 0) {
+ if (check_double_action(action, *argv))
+ return -1;
+ action = TCA_MPLS_ACT_DEC_TTL;
+ } else if (matches(*argv, "label") == 0) {
+ if (!can_modify_mpls_fields(action))
+ invarg("only valid for push/modify", *argv);
+ NEXT_ARG();
+ if (get_u32(&label, *argv, 0) || !is_valid_label(label))
+ invarg("label must be <=0xFFFFF", *argv);
+ } else if (matches(*argv, "tc") == 0) {
+ if (!can_modify_mpls_fields(action))
+ invarg("only valid for push/modify", *argv);
+ NEXT_ARG();
+ if (get_u8(&tc, *argv, 0) || (tc & ~0x7))
+ invarg("tc field is 3 bits max", *argv);
+ } else if (matches(*argv, "ttl") == 0) {
+ if (!can_modify_mpls_fields(action))
+ invarg("only valid for push/modify", *argv);
+ NEXT_ARG();
+ if (get_u8(&ttl, *argv, 0) || !ttl)
+ invarg("ttl must be >0 and <=255", *argv);
+ } else if (matches(*argv, "bos") == 0) {
+ if (!can_modify_mpls_fields(action))
+ invarg("only valid for push/modify", *argv);
+ NEXT_ARG();
+ if (get_u8(&bos, *argv, 0) || (bos & ~0x1))
+ invarg("bos must be 0 or 1", *argv);
+ } else if (matches(*argv, "protocol") == 0) {
+ if (!can_modify_ethtype(action))
+ invarg("only valid for push/pop", *argv);
+ NEXT_ARG();
+ if (ll_proto_a2n(&proto, *argv))
+ invarg("protocol is invalid", *argv);
+ } else if (matches(*argv, "help") == 0) {
+ usage();
+ } else {
+ break;
+ }
+
+ NEXT_ARG_FWD();
+ }
+
+ if (!action)
+ incomplete_command();
+
+ parse_action_control_dflt(&argc, &argv, &parm.action,
+ false, TC_ACT_PIPE);
+
+ if (argc) {
+ if (matches(*argv, "index") == 0) {
+ NEXT_ARG();
+ if (get_u32(&parm.index, *argv, 10))
+ invarg("illegal index", *argv);
+ NEXT_ARG_FWD();
+ }
+ }
+
+ if (action == TCA_MPLS_ACT_PUSH && !label)
+ missarg("label");
+
+ if (action == TCA_MPLS_ACT_PUSH && proto &&
+ proto != htons(ETH_P_MPLS_UC) && proto != htons(ETH_P_MPLS_MC)) {
+ fprintf(stderr,
+ "invalid push protocol \"0x%04x\" - use mpls_(uc|mc)\n",
+ ntohs(proto));
+ return -1;
+ }
+
+ if (action == TCA_MPLS_ACT_POP && !proto)
+ missarg("protocol");
+
+ parm.m_action = action;
+ tail = addattr_nest(n, MAX_MSG, tca_id | NLA_F_NESTED);
+ addattr_l(n, MAX_MSG, TCA_MPLS_PARMS, &parm, sizeof(parm));
+ if (label != 0xffffffff)
+ addattr_l(n, MAX_MSG, TCA_MPLS_LABEL, &label, sizeof(label));
+ if (proto)
+ addattr_l(n, MAX_MSG, TCA_MPLS_PROTO, &proto, sizeof(proto));
+ if (tc != 0xff)
+ addattr8(n, MAX_MSG, TCA_MPLS_TC, tc);
+ if (ttl)
+ addattr8(n, MAX_MSG, TCA_MPLS_TTL, ttl);
+ if (bos != 0xff)
+ addattr8(n, MAX_MSG, TCA_MPLS_BOS, bos);
+ addattr_nest_end(n, tail);
+
+ *argc_p = argc;
+ *argv_p = argv;
+ return 0;
+}
+
+static int print_mpls(struct action_util *au, FILE *f, struct rtattr *arg)
+{
+ struct rtattr *tb[TCA_MPLS_MAX + 1];
+ struct tc_mpls *parm;
+ SPRINT_BUF(b1);
+ __u32 val;
+
+ if (!arg)
+ return -1;
+
+ parse_rtattr_nested(tb, TCA_MPLS_MAX, arg);
+
+ if (!tb[TCA_MPLS_PARMS]) {
+ print_string(PRINT_FP, NULL, "%s", "[NULL mpls parameters]");
+ return -1;
+ }
+ parm = RTA_DATA(tb[TCA_MPLS_PARMS]);
+
+ print_string(PRINT_ANY, "kind", "%s ", "mpls");
+ print_string(PRINT_ANY, "mpls_action", " %s",
+ action_names[parm->m_action]);
+
+ switch (parm->m_action) {
+ case TCA_MPLS_ACT_POP:
+ if (tb[TCA_MPLS_PROTO]) {
+ __u16 proto;
+
+ proto = rta_getattr_u16(tb[TCA_MPLS_PROTO]);
+ print_string(PRINT_ANY, "protocol", " protocol %s",
+ ll_proto_n2a(proto, b1, sizeof(b1)));
+ }
+ break;
+ case TCA_MPLS_ACT_PUSH:
+ if (tb[TCA_MPLS_PROTO]) {
+ __u16 proto;
+
+ proto = rta_getattr_u16(tb[TCA_MPLS_PROTO]);
+ print_string(PRINT_ANY, "protocol", " protocol %s",
+ ll_proto_n2a(proto, b1, sizeof(b1)));
+ }
+ /* Fallthrough */
+ case TCA_MPLS_ACT_MODIFY:
+ if (tb[TCA_MPLS_LABEL]) {
+ val = rta_getattr_u32(tb[TCA_MPLS_LABEL]);
+ print_uint(PRINT_ANY, "label", " label %u", val);
+ }
+ if (tb[TCA_MPLS_TC]) {
+ val = rta_getattr_u8(tb[TCA_MPLS_TC]);
+ print_uint(PRINT_ANY, "tc", " tc %u", val);
+ }
+ if (tb[TCA_MPLS_BOS]) {
+ val = rta_getattr_u8(tb[TCA_MPLS_BOS]);
+ print_uint(PRINT_ANY, "bos", " bos %u", val);
+ }
+ if (tb[TCA_MPLS_TTL]) {
+ val = rta_getattr_u8(tb[TCA_MPLS_TTL]);
+ print_uint(PRINT_ANY, "ttl", " ttl %u", val);
+ }
+ break;
+ }
+ print_action_control(f, " ", parm->action, "");
+
+ print_uint(PRINT_ANY, "index", "\n\t index %u", parm->index);
+ print_int(PRINT_ANY, "ref", " ref %d", parm->refcnt);
+ print_int(PRINT_ANY, "bind", " bind %d", parm->bindcnt);
+
+ if (show_stats) {
+ if (tb[TCA_MPLS_TM]) {
+ struct tcf_t *tm = RTA_DATA(tb[TCA_MPLS_TM]);
+
+ print_tm(f, tm);
+ }
+ }
+
+ print_string(PRINT_FP, NULL, "%s", "\n");
+
+ return 0;
+}
+
+struct action_util mpls_action_util = {
+ .id = "mpls",
+ .parse_aopt = parse_mpls,
+ .print_aopt = print_mpls,
+};
--
2.7.4
