diff options
Diffstat (limited to 'tc/m_nat.c')
| -rw-r--r-- | tc/m_nat.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/tc/m_nat.c b/tc/m_nat.c new file mode 100644 index 0000000..95b3558 --- /dev/null +++ b/tc/m_nat.c @@ -0,0 +1,195 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * m_nat.c NAT module + * + * Authors: Herbert Xu <herbert@gondor.apana.org.au> + */ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <arpa/inet.h> +#include <string.h> +#include "utils.h" +#include "tc_util.h" +#include <linux/tc_act/tc_nat.h> + +static void +explain(void) +{ + fprintf(stderr, "Usage: ... nat NAT\n" + "NAT := DIRECTION OLD NEW\n" + "DIRECTION := { ingress | egress }\n" + "OLD := PREFIX\n" + "NEW := ADDRESS\n"); +} + +static void +usage(void) +{ + explain(); + exit(-1); +} + +static int +parse_nat_args(int *argc_p, char ***argv_p, struct tc_nat *sel) +{ + int argc = *argc_p; + char **argv = *argv_p; + inet_prefix addr; + + if (argc <= 0) + return -1; + + if (matches(*argv, "egress") == 0) + sel->flags |= TCA_NAT_FLAG_EGRESS; + else if (matches(*argv, "ingress") != 0) + goto bad_val; + + NEXT_ARG(); + + if (get_prefix_1(&addr, *argv, AF_INET)) + goto bad_val; + + sel->old_addr = addr.data[0]; + sel->mask = htonl(~0u << (32 - addr.bitlen)); + + NEXT_ARG(); + + if (get_prefix_1(&addr, *argv, AF_INET)) + goto bad_val; + + sel->new_addr = addr.data[0]; + + argc--; + argv++; + + *argc_p = argc; + *argv_p = argv; + return 0; + +bad_val: + return -1; +} + +static int +parse_nat(struct action_util *a, int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n) +{ + struct tc_nat sel = {}; + + int argc = *argc_p; + char **argv = *argv_p; + int ok = 0; + struct rtattr *tail; + + while (argc > 0) { + if (matches(*argv, "nat") == 0) { + NEXT_ARG(); + if (strcmp(*argv, "index") == 0) { + goto skip_args; + } else if (parse_nat_args(&argc, &argv, &sel)) { + fprintf(stderr, "Illegal nat construct (%s)\n", + *argv); + explain(); + return -1; + } + ok++; + continue; + } else if (matches(*argv, "help") == 0) { + usage(); + } else { + break; + } + + } + + if (!ok) { + explain(); + return -1; + } + + parse_action_control_dflt(&argc, &argv, &sel.action, false, TC_ACT_OK); + + if (argc) { + if (matches(*argv, "index") == 0) { +skip_args: + NEXT_ARG(); + if (get_u32(&sel.index, *argv, 10)) { + fprintf(stderr, "Nat: Illegal \"index\"\n"); + return -1; + } + argc--; + argv++; + } + } + + tail = addattr_nest(n, MAX_MSG, tca_id); + addattr_l(n, MAX_MSG, TCA_NAT_PARMS, &sel, sizeof(sel)); + addattr_nest_end(n, tail); + + *argc_p = argc; + *argv_p = argv; + return 0; +} + +static int +print_nat(struct action_util *au, FILE * f, struct rtattr *arg) +{ + struct tc_nat *sel; + struct rtattr *tb[TCA_NAT_MAX + 1]; + SPRINT_BUF(buf1); + SPRINT_BUF(buf2); + int len; + + print_string(PRINT_ANY, "type", " %s ", "nat"); + if (arg == NULL) + return 0; + + parse_rtattr_nested(tb, TCA_NAT_MAX, arg); + + if (tb[TCA_NAT_PARMS] == NULL) { + fprintf(stderr, "Missing nat parameters\n"); + return -1; + } + sel = RTA_DATA(tb[TCA_NAT_PARMS]); + + len = ffs(sel->mask); + len = len ? 33 - len : 0; + + print_string(PRINT_ANY, "direction", "%s", + sel->flags & TCA_NAT_FLAG_EGRESS ? "egress" : "ingress"); + + snprintf(buf2, sizeof(buf2), "%s/%d", + format_host_r(AF_INET, 4, &sel->old_addr, buf1, sizeof(buf1)), + len); + print_string(PRINT_ANY, "old_addr", " %s", buf2); + print_string(PRINT_ANY, "new_addr", " %s", + format_host_r(AF_INET, 4, &sel->new_addr, buf1, sizeof(buf1))); + + print_action_control(f, " ", sel->action, ""); + print_nl(); + print_uint(PRINT_ANY, "index", "\t index %u", sel->index); + print_int(PRINT_ANY, "ref", " ref %d", sel->refcnt); + print_int(PRINT_ANY, "bind", " bind %d", sel->bindcnt); + + if (show_stats) { + if (tb[TCA_NAT_TM]) { + struct tcf_t *tm = RTA_DATA(tb[TCA_NAT_TM]); + + print_tm(f, tm); + } + } + + print_nl(); + + return 0; +} + +struct action_util nat_action_util = { + .id = "nat", + .parse_aopt = parse_nat, + .print_aopt = print_nat, +}; |