git: 1cd332adc86a - main - ifconfig: Add gre netlink support
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Date: Thu, 30 Jul 2026 18:11:53 UTC
The branch main has been updated by pouria:
URL: https://cgit.FreeBSD.org/src/commit/?id=1cd332adc86a551b9c498ee6e86f161eb5641b68
commit 1cd332adc86a551b9c498ee6e86f161eb5641b68
Author: Pouria Mousavizadeh Tehrani <pouria@FreeBSD.org>
AuthorDate: 2026-07-30 17:53:39 +0000
Commit: Pouria Mousavizadeh Tehrani <pouria@FreeBSD.org>
CommitDate: 2026-07-30 17:54:07 +0000
ifconfig: Add gre netlink support
Implement netlink support for gre in ifconfig
Differential Revision: https://reviews.freebsd.org/D55366
---
sbin/ifconfig/ifgre.c | 274 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 274 insertions(+)
diff --git a/sbin/ifconfig/ifgre.c b/sbin/ifconfig/ifgre.c
index c3d3856e0b09..c704aa66b275 100644
--- a/sbin/ifconfig/ifgre.c
+++ b/sbin/ifconfig/ifgre.c
@@ -41,12 +41,277 @@
#include "ifconfig.h"
+#ifndef WITHOUT_NETLINK
+#include "ifconfig_netlink.h"
+#endif
+
static const char *GREBITS[] = {
[0] = "ENABLE_CSUM",
[1] = "ENABLE_SEQ",
[2] = "UDPENCAP",
};
+#ifndef WITHOUT_NETLINK
+struct nl_parsed_gre {
+ uint32_t ifla_flags;
+ uint32_t ifla_okey;
+ uint32_t ifla_encap_type;
+ uint16_t ifla_encap_sport;
+};
+
+struct nla_gre_info {
+ const char *kind;
+ struct nl_parsed_gre data;
+};
+
+struct nla_gre_link {
+ uint32_t ifi_index;
+ struct nla_gre_info linkinfo;
+};
+
+static inline void
+gre_nl_init(if_ctx *ctx, struct snl_writer *nw, uint32_t flags)
+{
+ struct nlmsghdr *hdr;
+
+ snl_init_writer(ctx->io_ss, nw);
+ hdr = snl_create_msg_request(nw, NL_RTM_NEWLINK);
+ hdr->nlmsg_flags |= flags;
+ snl_reserve_msg_object(nw, struct ifinfomsg);
+ snl_add_msg_attr_string(nw, IFLA_IFNAME, ctx->ifname);
+}
+
+static inline void
+gre_nl_fini(if_ctx *ctx, struct snl_writer *nw)
+{
+ struct nlmsghdr *hdr;
+ struct snl_errmsg_data errmsg = {};
+
+ hdr = snl_finalize_msg(nw);
+ if (hdr == NULL || !snl_send_message(ctx->io_ss, hdr))
+ err(1, "unable to send netlink message");
+
+ if (!snl_read_reply_code(ctx->io_ss, hdr->nlmsg_seq, &errmsg))
+ errx(errmsg.error, "%s", errmsg.error_str);
+}
+
+#define _OUT(_field) offsetof(struct nl_parsed_gre, _field)
+static const struct snl_attr_parser nla_p_gre[] = {
+ { .type = IFLA_GRE_FLAGS, .off = _OUT(ifla_flags), .cb = snl_attr_get_uint32 },
+ { .type = IFLA_GRE_OKEY, .off = _OUT(ifla_okey), .cb = snl_attr_get_uint32 },
+ { .type = IFLA_GRE_ENCAP_TYPE, .off = _OUT(ifla_encap_type),
+ .cb = snl_attr_get_uint32 },
+ { .type = IFLA_GRE_ENCAP_SPORT, .off = _OUT(ifla_encap_sport),
+ .cb = snl_attr_get_uint16 },
+};
+#undef _OUT
+SNL_DECLARE_ATTR_PARSER(gre_linkinfo_data_parser, nla_p_gre);
+
+#define _OUT(_field) offsetof(struct nla_gre_info, _field)
+static const struct snl_attr_parser ap_gre_linkinfo[] = {
+ { .type = IFLA_INFO_KIND, .off = _OUT(kind), .cb = snl_attr_get_string },
+ { .type = IFLA_INFO_DATA, .off = _OUT(data),
+ .arg = &gre_linkinfo_data_parser, .cb = snl_attr_get_nested },
+};
+#undef _OUT
+SNL_DECLARE_ATTR_PARSER(gre_linkinfo_parser, ap_gre_linkinfo);
+
+#define _IN(_field) offsetof(struct ifinfomsg, _field)
+#define _OUT(_field) offsetof(struct nla_gre_link, _field)
+static const struct snl_attr_parser ap_gre_link[] = {
+ { .type = IFLA_LINKINFO, .off = _OUT(linkinfo),
+ .arg = &gre_linkinfo_parser, .cb = snl_attr_get_nested },
+};
+
+static const struct snl_field_parser fp_geneve_link[] = {
+ { .off_in = _IN(ifi_index), .off_out = _OUT(ifi_index),
+ .cb = snl_field_get_uint32 },
+};
+#undef _IN
+#undef _OUT
+SNL_DECLARE_PARSER(gre_parser, struct ifinfomsg, fp_geneve_link, ap_gre_link);
+
+static const struct snl_hdr_parser *all_parsers[] = {
+ &gre_linkinfo_data_parser,
+ &gre_linkinfo_parser,
+ &gre_parser,
+};
+
+static void
+gre_status_nl(if_ctx *ctx)
+{
+ struct snl_writer nw = {};
+ struct nlmsghdr *hdr;
+ struct snl_errmsg_data errmsg = {};
+ struct nla_gre_link gre_link = {};
+
+ if (strncmp(ctx->ifname, "gre", sizeof("gre") - 1) != 0)
+ return;
+
+ snl_init_writer(ctx->io_ss, &nw);
+ hdr = snl_create_msg_request(&nw, NL_RTM_GETLINK);
+ hdr->nlmsg_flags |= NLM_F_DUMP;
+ snl_reserve_msg_object(&nw, struct ifinfomsg);
+ snl_add_msg_attr_string(&nw, IFLA_IFNAME, ctx->ifname);
+
+ hdr = snl_finalize_msg(&nw);
+ if (hdr == NULL || !snl_send_message(ctx->io_ss, hdr))
+ err(1, "unable to send netlink message");
+
+ hdr = snl_read_reply(ctx->io_ss, hdr->nlmsg_seq);
+ if (hdr->nlmsg_type != NL_RTM_NEWLINK) {
+ if (!snl_parse_errmsg(ctx->io_ss, hdr, &errmsg))
+ errx(EINVAL, "(NETLINK)");
+ if (errmsg.error_str != NULL)
+ errx(errmsg.error, "(NETLINK) %s", errmsg.error_str);
+ }
+
+ if (!snl_parse_nlmsg(ctx->io_ss, hdr, &gre_parser, &gre_link))
+ return;
+
+ struct nla_gre_info gre_info = gre_link.linkinfo;
+ struct nl_parsed_gre gre_data = gre_info.data;
+
+ if (gre_data.ifla_okey != 0)
+ printf("\tgrekey: 0x%x (%u)\n",
+ gre_data.ifla_okey, gre_data.ifla_okey);
+
+ if (gre_data.ifla_flags == 0)
+ return;
+
+ if (gre_data.ifla_encap_sport != 0)
+ printf("\tudpport: %u\n", gre_data.ifla_encap_sport);
+
+ printf("\toptions=%x", gre_data.ifla_flags);
+ print_bits("options", &gre_data.ifla_flags, 1, GREBITS, nitems(GREBITS));
+ putchar('\n');
+}
+
+static void
+setifgrekey_nl(if_ctx *ctx, const char *val, int dummy __unused)
+{
+ struct snl_writer nw = {};
+ int off, off2;
+ uint32_t grekey = strtol(val, NULL, 0);
+
+ gre_nl_init(ctx, &nw, 0);
+ off = snl_add_msg_attr_nested(&nw, IFLA_LINKINFO);
+ snl_add_msg_attr_string(&nw, IFLA_INFO_KIND, "gre");
+
+ off2 = snl_add_msg_attr_nested(&nw, IFLA_INFO_DATA);
+ snl_add_msg_attr_u32(&nw, IFLA_GRE_OKEY, grekey);
+
+ snl_end_attr_nested(&nw, off2);
+ snl_end_attr_nested(&nw, off);
+
+ gre_nl_fini(ctx, &nw);
+}
+
+static void
+setifgreport_nl(if_ctx *ctx, const char *val, int dummy __unused)
+{
+ struct snl_writer nw = {};
+ int off, off2;
+ uint16_t greport = strtol(val, NULL, 0);
+
+ gre_nl_init(ctx, &nw, 0);
+ off = snl_add_msg_attr_nested(&nw, IFLA_LINKINFO);
+ snl_add_msg_attr_string(&nw, IFLA_INFO_KIND, "gre");
+
+ off2 = snl_add_msg_attr_nested(&nw, IFLA_INFO_DATA);
+ snl_add_msg_attr_u16(&nw, IFLA_GRE_ENCAP_SPORT, greport);
+
+ snl_end_attr_nested(&nw, off2);
+ snl_end_attr_nested(&nw, off);
+
+ gre_nl_fini(ctx, &nw);
+}
+
+static void
+setifgreopts_nl(if_ctx *ctx, const char *val __unused, int d)
+{
+ struct snl_writer nw = {};
+ struct nlmsghdr *hdr;
+ struct snl_errmsg_data errmsg;
+ struct nla_gre_link gre_link;
+ int off, off2;
+
+ snl_init_writer(ctx->io_ss, &nw);
+ hdr = snl_create_msg_request(&nw, NL_RTM_GETLINK);
+ hdr->nlmsg_flags |= NLM_F_DUMP;
+ snl_reserve_msg_object(&nw, struct ifinfomsg);
+ snl_add_msg_attr_string(&nw, IFLA_IFNAME, ctx->ifname);
+
+ hdr = snl_finalize_msg(&nw);
+ if (hdr == NULL || (!snl_send_message(ctx->io_ss, hdr)))
+ err(1, "unable to send netlink message");
+
+ hdr = snl_read_reply(ctx->io_ss, hdr->nlmsg_seq);
+ if (hdr->nlmsg_type != NL_RTM_NEWLINK) {
+ if (!snl_parse_errmsg(ctx->io_ss, hdr, &errmsg))
+ errx(EINVAL, "(NETLINK)");
+ if (errmsg.error_str != NULL)
+ errx(errmsg.error, "(NETLINK) %s", errmsg.error_str);
+ }
+
+ if (!snl_parse_nlmsg(ctx->io_ss, hdr, &gre_parser, &gre_link))
+ return;
+
+ struct nla_gre_info gre_info = gre_link.linkinfo;
+ struct nl_parsed_gre gre_data = gre_info.data;
+
+ if (d < 0)
+ gre_data.ifla_flags &= ~(-d);
+ else
+ gre_data.ifla_flags |= d;
+
+ gre_nl_init(ctx, &nw, 0);
+ off = snl_add_msg_attr_nested(&nw, IFLA_LINKINFO);
+ snl_add_msg_attr_string(&nw, IFLA_INFO_KIND, "gre");
+
+ off2 = snl_add_msg_attr_nested(&nw, IFLA_INFO_DATA);
+ snl_add_msg_attr_u32(&nw, IFLA_GRE_FLAGS, gre_data.ifla_flags);
+
+ snl_end_attr_nested(&nw, off2);
+ snl_end_attr_nested(&nw, off);
+
+ gre_nl_fini(ctx, &nw);
+}
+
+static void
+setifgretype_nl(if_ctx *ctx, const char *val __unused, int d)
+{
+ struct snl_writer nw = {};
+ int off, off2;
+ uint32_t type;
+
+ gre_nl_init(ctx, &nw, 0);
+ off = snl_add_msg_attr_nested(&nw, IFLA_LINKINFO);
+ snl_add_msg_attr_string(&nw, IFLA_INFO_KIND, "gre");
+
+ off2 = snl_add_msg_attr_nested(&nw, IFLA_INFO_DATA);
+ type = d < 0 ? IFLA_TUNNEL_NONE : IFLA_TUNNEL_GRE_UDP;
+ snl_add_msg_attr_u32(&nw, IFLA_GRE_ENCAP_TYPE, type);
+
+ snl_end_attr_nested(&nw, off2);
+ snl_end_attr_nested(&nw, off);
+
+ gre_nl_fini(ctx, &nw);
+}
+
+
+static struct cmd gre_cmds[] = {
+ DEF_CMD_ARG("grekey", setifgrekey_nl),
+ DEF_CMD_ARG("udpport", setifgreport_nl),
+ DEF_CMD("enable_csum", GRE_ENABLE_CSUM, setifgreopts_nl),
+ DEF_CMD("-enable_csum",-GRE_ENABLE_CSUM,setifgreopts_nl),
+ DEF_CMD("enable_seq", GRE_ENABLE_SEQ, setifgreopts_nl),
+ DEF_CMD("-enable_seq",-GRE_ENABLE_SEQ, setifgreopts_nl),
+ DEF_CMD("udpencap", GRE_UDPENCAP, setifgretype_nl),
+ DEF_CMD("-udpencap",-GRE_UDPENCAP, setifgretype_nl),
+};
+
+#else
static void
gre_status(if_ctx *ctx)
{
@@ -123,10 +388,16 @@ static struct cmd gre_cmds[] = {
DEF_CMD("udpencap", GRE_UDPENCAP, setifgreopts),
DEF_CMD("-udpencap",-GRE_UDPENCAP, setifgreopts),
};
+#endif /* !WITHOUT_NETLINK */
+
static struct afswtch af_gre = {
.af_name = "af_gre",
.af_af = AF_UNSPEC,
+#ifndef WITHOUT_NETLINK
+ .af_other_status = gre_status_nl,
+#else
.af_other_status = gre_status,
+#endif
};
static __constructor void
@@ -137,4 +408,7 @@ gre_ctor(void)
for (i = 0; i < nitems(gre_cmds); i++)
cmd_register(&gre_cmds[i]);
af_register(&af_gre);
+#ifndef WITHOUT_NETLINK
+ SNL_VERIFY_PARSERS(all_parsers);
+#endif
}