Subject: Re: [PATCH iproute2 3/3] ip: add support of 'ip link type [ipip|sit]'

From: Stephen Hemminger <[email-masked]>
Date: Wed, 12 Dec 2012 09:11:18 -0800

On Wed, 12 Dec 2012 10:51:47 +0100
Nicolas Dichtel <[email-masked]> wrote:

> This patch allows to manage ip tunnels via the interface ip link.
> The syntax for parameters is the same that 'ip tunnel'.
> 
> It also allows to display tunnels parameters with 'ip -details link' or
> 'ip -details monitor link'.
> 
> Signed-off-by: Nicolas Dichtel <[email-masked]>
> ---
>  ip/Makefile     |   3 +-
>  ip/iplink.c     |   2 +-
>  ip/link_iptnl.c | 340 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 343 insertions(+), 2 deletions(-)
>  create mode 100644 ip/link_iptnl.c
> 
> diff --git a/ip/Makefile b/ip/Makefile
> index abf54bf..2b606d4 100644
> --- a/ip/Makefile
> +++ b/ip/Makefile
> @@ -4,7 +4,8 @@ IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o ipnetns.o \
>      ipxfrm.o xfrm_state.o xfrm_policy.o xfrm_monitor.o \
>      iplink_vlan.o link_veth.o link_gre.o iplink_can.o \
>      iplink_macvlan.o iplink_macvtap.o ipl2tp.o link_vti.o \
> -    iplink_vxlan.o tcp_metrics.o iplink_ipoib.o ipnetconf.o link_ip6tnl.o
> +    iplink_vxlan.o tcp_metrics.o iplink_ipoib.o ipnetconf.o link_ip6tnl.o \
> +    link_iptnl.o
>  
>  RTMONOBJ=rtmon.o
>  
> diff --git a/ip/iplink.c b/ip/iplink.c
> index 8aac9fc..d73c705 100644
> --- a/ip/iplink.c
> +++ b/ip/iplink.c
> @@ -84,7 +84,7 @@ void iplink_usage(void)
>  	if (iplink_have_newlink()) {
>  		fprintf(stderr, "\n");
>  		fprintf(stderr, "TYPE := { vlan | veth | vcan | dummy | ifb | macvlan | can |\n");
> -		fprintf(stderr, "          bridge | ipoib | ip6tnl }\n");
> +		fprintf(stderr, "          bridge | ipoib | ip6tnl | ipip | sit }\n");
>  	}
>  	exit(-1);
>  }
> diff --git a/ip/link_iptnl.c b/ip/link_iptnl.c
> new file mode 100644
> index 0000000..238722d
> --- /dev/null
> +++ b/ip/link_iptnl.c
> @@ -0,0 +1,340 @@
> +/*
> + * link_iptnl.c	ipip and sit driver module
> + *
> + *		This program is free software; you can redistribute it and/or
> + *		modify it under the terms of the GNU General Public License
> + *		as published by the Free Software Foundation; either version
> + *		2 of the License, or (at your option) any later version.
> + *
> + * Authors:	Nicolas Dichtel <[email-masked]>
> + *
> + */
> +
> +#include <string.h>
> +#include <net/if.h>
> +#include <sys/types.h>
> +#include <sys/socket.h>
> +#include <arpa/inet.h>
> +
> +#include <linux/ip.h>
> +#include <linux/if_tunnel.h>
> +#include "rt_names.h"
> +#include "utils.h"
> +#include "ip_common.h"
> +#include "tunnel.h"
> +
> +static void usage(int sit) __attribute__((noreturn));
> +static void usage(int sit)
> +{
> +	fprintf(stderr, "Usage: ip link { add | set | change | replace | del } NAME\n");
> +	fprintf(stderr, "          type { ipip | sit } [ remote ADDR ] [ local ADDR ]\n");
> +	fprintf(stderr, "          [ ttl TTL ] [ tos TOS ] [ [no]pmtudisc ] [ dev PHYS_DEV ]\n");
> +	fprintf(stderr, "          [ 6rd-prefix ADDR ] [ 6rd-relay_prefix ADDR ] [ 6rd-reset ]\n");
> +	if (sit)
> +		fprintf(stderr, "          [ isatap ]\n");
> +	fprintf(stderr, "\n");
> +	fprintf(stderr, "Where: NAME := STRING\n");
> +	fprintf(stderr, "       ADDR := { IP_ADDRESS | any }\n");
> +	fprintf(stderr, "       TOS  := { NUMBER | inherit }\n");
> +	fprintf(stderr, "       TTL  := { 1..255 | inherit }\n");
> +	exit(-1);
> +}
> +
> +static int iptunnel_parse_opt(struct link_util *lu, int argc, char **argv,
> +			      struct nlmsghdr *n)
> +{
> +	struct {
> +		struct nlmsghdr n;
> +		struct ifinfomsg i;
> +		char buf[2048];
> +	} req;
> +	struct ifinfomsg *ifi = (struct ifinfomsg *)(n + 1);
> +	struct rtattr *tb[IFLA_MAX + 1];
> +	struct rtattr *linkinfo[IFLA_INFO_MAX+1];
> +	struct rtattr *iptuninfo[IFLA_IPTUN_MAX + 1];
> +	int len;
> +	__u32 link = 0;
> +	__u32 laddr = 0;
> +	__u32 raddr = 0;
> +	__u8 ttl = 0;
> +	__u8 tos = 0;
> +	__u8 pmtudisc = 1;
> +	__u16 iflags = 0;
> +	struct in6_addr ip6rdprefix;
> +	__u16 ip6rdprefixlen = 0;
> +	__u32 ip6rdrelayprefix = 0;
> +	__u16 ip6rdrelayprefixlen = 0;
> +
> +	memset(&ip6rdprefix, 0, sizeof(ip6rdprefix));
> +
> +	if (!(n->nlmsg_flags & NLM_F_CREATE)) {
> +		memset(&req, 0, sizeof(req));
> +
> +		req.n.nlmsg_len = NLMSG_LENGTH(sizeof(*ifi));
> +		req.n.nlmsg_flags = NLM_F_REQUEST;
> +		req.n.nlmsg_type = RTM_GETLINK;
> +		req.i.ifi_family = preferred_family;
> +		req.i.ifi_index = ifi->ifi_index;
> +
> +		if (rtnl_talk(&rth, &req.n, 0, 0, &req.n) < 0) {
> +get_failed:
> +			fprintf(stderr,
> +				"Failed to get existing tunnel info.\n");
> +			return -1;
> +		}
> +
> +		len = req.n.nlmsg_len;
> +		len -= NLMSG_LENGTH(sizeof(*ifi));
> +		if (len < 0)
> +			goto get_failed;
> +
> +		parse_rtattr(tb, IFLA_MAX, IFLA_RTA(&req.i), len);
> +
> +		if (!tb[IFLA_LINKINFO])
> +			goto get_failed;
> +
> +		parse_rtattr_nested(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO]);
> +
> +		if (!linkinfo[IFLA_INFO_DATA])
> +			goto get_failed;
> +
> +		parse_rtattr_nested(iptuninfo, IFLA_IPTUN_MAX,
> +				    linkinfo[IFLA_INFO_DATA]);
> +
> +		if (iptuninfo[IFLA_IPTUN_LOCAL])
> +			laddr = rta_getattr_u32(iptuninfo[IFLA_IPTUN_LOCAL]);
> +
> +		if (iptuninfo[IFLA_IPTUN_REMOTE])
> +			raddr = rta_getattr_u32(iptuninfo[IFLA_IPTUN_REMOTE]);
> +
> +		if (iptuninfo[IFLA_IPTUN_TTL])
> +			ttl = rta_getattr_u8(iptuninfo[IFLA_IPTUN_TTL]);
> +
> +		if (iptuninfo[IFLA_IPTUN_TOS])
> +			tos = rta_getattr_u8(iptuninfo[IFLA_IPTUN_TOS]);
> +
> +		if (iptuninfo[IFLA_IPTUN_PMTUDISC])
> +			pmtudisc =
> +				rta_getattr_u8(iptuninfo[IFLA_IPTUN_PMTUDISC]);
> +
> +		if (iptuninfo[IFLA_IPTUN_FLAGS])
> +			iflags = rta_getattr_u16(iptuninfo[IFLA_IPTUN_FLAGS]);
> +
> +		if (iptuninfo[IFLA_IPTUN_LINK])
> +			link = rta_getattr_u32(iptuninfo[IFLA_IPTUN_LINK]);
> +
> +		if (iptuninfo[IFLA_IPTUN_6RD_PREFIX])
> +			memcpy(&ip6rdprefix,
> +			       RTA_DATA(iptuninfo[IFLA_IPTUN_6RD_PREFIX]),
> +			       sizeof(laddr));
> +
> +		if (iptuninfo[IFLA_IPTUN_6RD_PREFIXLEN])
> +			ip6rdprefixlen =
> +				rta_getattr_u16(iptuninfo[IFLA_IPTUN_6RD_PREFIXLEN]);
> +
> +		if (iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIX])
> +			ip6rdrelayprefix =
> +				rta_getattr_u32(iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIX]);
> +
> +		if (iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIXLEN])
> +			ip6rdrelayprefixlen =
> +				rta_getattr_u16(iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
> +	}
> +
> +	while (argc > 0) {
> +		if (strcmp(*argv, "remote") == 0) {
> +			NEXT_ARG();
> +			if (strcmp(*argv, "any"))
> +				raddr = get_addr32(*argv);
> +			else
> +				raddr = 0;
> +		} else if (strcmp(*argv, "local") == 0) {
> +			NEXT_ARG();
> +			if (strcmp(*argv, "any"))
> +				laddr = get_addr32(*argv);
> +			else
> +				laddr = 0;
> +		} else if (matches(*argv, "dev") == 0) {
> +			NEXT_ARG();
> +			link = if_nametoindex(*argv);
> +			if (link == 0)
> +				invarg("\"dev\" is invalid", *argv);
> +		} else if (strcmp(*argv, "ttl") == 0 ||
> +			   strcmp(*argv, "hoplimit") == 0) {
> +			NEXT_ARG();
> +			if (strcmp(*argv, "inherit") != 0) {
> +				if (get_u8(&ttl, *argv, 0))
> +					invarg("invalid TTL\n", *argv);
> +			} else
> +				ttl = 0;
> +		} else if (strcmp(*argv, "tos") == 0 ||
> +			   strcmp(*argv, "tclass") == 0 ||
> +			   matches(*argv, "dsfield") == 0) {
> +			__u32 uval;
> +			NEXT_ARG();
> +			if (strcmp(*argv, "inherit") != 0) {
> +				if (rtnl_dsfield_a2n(&uval, *argv))
> +					invarg("bad TOS value", *argv);
> +				tos = uval;
> +			} else
> +				tos = 1;
> +		} else if (strcmp(*argv, "nopmtudisc") == 0) {
> +			pmtudisc = 0;
> +		} else if (strcmp(*argv, "pmtudisc") == 0) {
> +			pmtudisc = 1;
> +		} else if (strcmp(lu->id, "sit") == 0 &&
> +			   strcmp(*argv, "isatap") == 0) {
> +			iflags |= SIT_ISATAP;
> +		} else if (strcmp(*argv, "6rd-prefix") == 0) {
> +			inet_prefix prefix;
> +			NEXT_ARG();
> +			if (get_prefix(&prefix, *argv, AF_INET6))
> +				invarg("invalid 6rd_prefix\n", *argv);
> +			memcpy(&ip6rdprefix, prefix.data, 16);
> +			ip6rdprefixlen = prefix.bitlen;
> +		} else if (strcmp(*argv, "6rd-relay_prefix") == 0) {
> +			inet_prefix prefix;
> +			NEXT_ARG();
> +			if (get_prefix(&prefix, *argv, AF_INET))
> +				invarg("invalid 6rd-relay_prefix\n", *argv);
> +			memcpy(&ip6rdrelayprefix, prefix.data, 4);
> +			ip6rdrelayprefixlen = prefix.bitlen;
> +		} else if (strcmp(*argv, "6rd-reset") == 0) {
> +			inet_prefix prefix;
> +			get_prefix(&prefix, "2002::", AF_INET6);
> +			memcpy(&ip6rdprefix, prefix.data, 16);
> +			ip6rdprefixlen = 16;
> +			ip6rdrelayprefix = 0;
> +			ip6rdrelayprefixlen = 0;
> +		} else
> +			usage(strcmp(lu->id, "sit") == 0);
> +		argc--, argv++;
> +	}
> +
> +	if (ttl && pmtudisc == 0) {
> +		fprintf(stderr, "ttl != 0 and noptmudisc are incompatible\n");
> +		exit(-1);
> +	}
> +
> +	addattr32(n, 1024, IFLA_IPTUN_LINK, link);
> +	addattr32(n, 1024, IFLA_IPTUN_LOCAL, laddr);
> +	addattr32(n, 1024, IFLA_IPTUN_REMOTE, raddr);
> +	addattr8(n, 1024, IFLA_IPTUN_TTL, ttl);
> +	addattr8(n, 1024, IFLA_IPTUN_TOS, tos);
> +	addattr8(n, 1024, IFLA_IPTUN_PMTUDISC, pmtudisc);
> +	if (strcmp(lu->id, "sit") == 0) {
> +		addattr16(n, 1024, IFLA_IPTUN_FLAGS, iflags);
> +		if (ip6rdprefixlen) {
> +			addattr_l(n, 1024, IFLA_IPTUN_6RD_PREFIX,
> +				  &ip6rdprefix, sizeof(ip6rdprefix));
> +			addattr16(n, 1024, IFLA_IPTUN_6RD_PREFIXLEN,
> +				  ip6rdprefixlen);
> +			addattr32(n, 1024, IFLA_IPTUN_6RD_RELAY_PREFIX,
> +				  ip6rdrelayprefix);
> +			addattr16(n, 1024, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
> +				  ip6rdrelayprefixlen);
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static void iptunnel_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
> +{
> +	char s1[1024];
> +	char s2[64];
> +	const char *local = "any";
> +	const char *remote = "any";
> +
> +	if (!tb)
> +		return;
> +
> +	if (tb[IFLA_IPTUN_REMOTE]) {
> +		unsigned addr = rta_getattr_u32(tb[IFLA_IPTUN_REMOTE]);
> +
> +		if (addr)
> +			remote = format_host(AF_INET, 4, &addr, s1, sizeof(s1));
> +	}
> +
> +	fprintf(f, "remote %s ", remote);
> +
> +	if (tb[IFLA_IPTUN_LOCAL]) {
> +		unsigned addr = rta_getattr_u32(tb[IFLA_IPTUN_LOCAL]);
> +
> +		if (addr)
> +			local = format_host(AF_INET, 4, &addr, s1, sizeof(s1));
> +	}
> +
> +	fprintf(f, "local %s ", local);
> +
> +	if (tb[IFLA_IPTUN_LINK] && rta_getattr_u32(tb[IFLA_IPTUN_LINK])) {
> +		unsigned link = rta_getattr_u32(tb[IFLA_IPTUN_LINK]);
> +		const char *n = if_indextoname(link, s2);
> +
> +		if (n)
> +			fprintf(f, "dev %s ", n);
> +		else
> +			fprintf(f, "dev %u ", link);
> +	}
> +
> +	if (tb[IFLA_IPTUN_TTL] && rta_getattr_u8(tb[IFLA_IPTUN_TTL]))
> +		fprintf(f, "ttl %d ", rta_getattr_u8(tb[IFLA_IPTUN_TTL]));
> +	else
> +		fprintf(f, "ttl inherit ");
> +
> +	if (tb[IFLA_IPTUN_TOS] && rta_getattr_u8(tb[IFLA_IPTUN_TOS])) {
> +		int tos = rta_getattr_u8(tb[IFLA_IPTUN_TOS]);
> +
> +		fputs("tos ", f);
> +		if (tos == 1)
> +			fputs("inherit ", f);
> +		else
> +			fprintf(f, "0x%x ", tos);
> +	}
> +
> +	if (tb[IFLA_IPTUN_PMTUDISC] && rta_getattr_u8(tb[IFLA_IPTUN_PMTUDISC]))
> +		fprintf(f, "pmtudisc ");
> +	else
> +		fprintf(f, "nopmtudisc ");
> +
> +	if (tb[IFLA_IPTUN_FLAGS]) {
> +	       __u16 iflags = rta_getattr_u16(tb[IFLA_IPTUN_FLAGS]);
> +
> +	      if (iflags & SIT_ISATAP)
> +		      fprintf(f, "isatap ");
> +	}
> +
> +	if (tb[IFLA_IPTUN_6RD_PREFIXLEN] &&
> +	    *(__u16 *)RTA_DATA(tb[IFLA_IPTUN_6RD_PREFIXLEN])) {
> +		__u16 prefixlen = rta_getattr_u16(tb[IFLA_IPTUN_6RD_PREFIXLEN]);
> +		__u16 relayprefixlen =
> +			rta_getattr_u16(tb[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
> +		__u32 relayprefix =
> +			rta_getattr_u32(tb[IFLA_IPTUN_6RD_RELAY_PREFIX]);
> +
> +		printf("6rd-prefix %s/%u ",
> +		       inet_ntop(AF_INET6, RTA_DATA(tb[IFLA_IPTUN_6RD_PREFIX]),
> +			         s1, sizeof(s1)),
> +		       prefixlen);
> +		if (relayprefix) {
> +			printf("6rd-relay_prefix %s/%u ",
> +			       format_host(AF_INET, 4, &relayprefix, s1,
> +				           sizeof(s1)),
> +			       relayprefixlen);
> +		}
> +	}
> +}
> +
> +struct link_util ipip_link_util = {
> +	.id = "ipip",
> +	.maxattr = IFLA_IPTUN_MAX,
> +	.parse_opt = iptunnel_parse_opt,
> +	.print_opt = iptunnel_print_opt,
> +};
> +
> +struct link_util sit_link_util = {
> +	.id = "sit",
> +	.maxattr = IFLA_IPTUN_MAX,
> +	.parse_opt = iptunnel_parse_opt,
> +	.print_opt = iptunnel_print_opt,
> +};

All applied with minor corrections to header files.

Could you please add man pages for this new functionality?