nixos: add support for Ubuntu Fan Networking

This provides support for Ubuntu Fan Networking [1].

This includes:

* The fanctl package, and a corresponding NixOS service.
* iproute patches.
* kernel patches.

closes #9188

1: https://wiki.ubuntu.com/FanNetworking

2 files changed, 169 insertions, 1 deletions

diff --git a/pkgs/os-specific/linux/iproute/default.nix b/pkgs/os-specific/linux/iproute/default.nix
index 6fea4ba05e0d..6f5ec27c638e 100644
--- a/pkgs/os-specific/linux/iproute/default.nix
+++ b/pkgs/os-specific/linux/iproute/default.nix
@@ -1,4 +1,6 @@
-{ fetchurl, stdenv, flex, bison, db, iptables, pkgconfig }:
+{ fetchurl, stdenv, lib, flex, bison, db, iptables, pkgconfig
+, enableFan ? false
+}:
 
 stdenv.mkDerivation rec {
   name = "iproute2-4.1.1";
@@ -8,6 +10,8 @@ stdenv.mkDerivation rec {
     sha256 = "0vz6m2k6hdrjlg4x0r3cd75lg9ysmndbsp35pm8494zvksc7l1vk";
   };
 
+  patches = lib.optionals enableFan [ ./ubuntu-fan.patch ];
+
   preConfigure = ''
     patchShebangs ./configure
     sed -e '/ARPDDIR/d' -i Makefile
diff --git a/pkgs/os-specific/linux/iproute/ubuntu-fan.patch b/pkgs/os-specific/linux/iproute/ubuntu-fan.patch
new file mode 100644
index 000000000000..e55425c2ce6a
--- /dev/null
+++ b/pkgs/os-specific/linux/iproute/ubuntu-fan.patch
@@ -0,0 +1,164 @@
+This provides support for Ubuntu's Fan Networking [1].
+
+These patches were pulled from:
+https://code.launchpad.net/~ubuntu-branches/ubuntu/vivid/iproute2/vivid-proposed
+
+See revisions 18 and 19.
+
+[1] https://wiki.ubuntu.com/FanNetworking
+
+diff --git a/include/linux/if_tunnel.h b/include/linux/if_tunnel.h
+index 102ce7a..7b8f0e5 100644
+--- a/include/linux/if_tunnel.h
++++ b/include/linux/if_tunnel.h
+@@ -57,6 +57,9 @@ enum {
+ 	IFLA_IPTUN_ENCAP_FLAGS,
+ 	IFLA_IPTUN_ENCAP_SPORT,
+ 	IFLA_IPTUN_ENCAP_DPORT,
++
++	IFLA_IPTUN_FAN_UNDERLAY = 32,
++	IFLA_IPTUN_FAN_MAP = 33,
+ 	__IFLA_IPTUN_MAX,
+ };
+ #define IFLA_IPTUN_MAX	(__IFLA_IPTUN_MAX - 1)
+@@ -131,4 +134,20 @@ enum {
+ };
+ 
+ #define IFLA_VTI_MAX	(__IFLA_VTI_MAX - 1)
++
++enum {
++	IFLA_FAN_UNSPEC,
++	IFLA_FAN_MAPPING,
++	__IFLA_FAN_MAX,
++};
++
++#define IFLA_FAN_MAX (__IFLA_FAN_MAX - 1)
++
++struct ip_tunnel_fan_map {
++	__be32		underlay;
++	__be32		overlay;
++	__u16		underlay_prefix;
++	__u16		overlay_prefix;
++};
++
+ #endif /* _IF_TUNNEL_H_ */
+diff --git a/ip/link_iptnl.c b/ip/link_iptnl.c
+index 9d6bc98..ec3f05d 100644
+--- a/ip/link_iptnl.c
++++ b/ip/link_iptnl.c
+@@ -49,6 +49,42 @@ static void usage(int sit)
+ 	print_usage(stderr, sit);
+ 	exit(-1);
+ }
++static int fan_parse_map(int *argcp, char ***argvp, struct nlmsghdr *n)
++{
++	inet_prefix underlay, overlay;
++	struct ip_tunnel_fan_map map;
++	struct rtattr *nest;
++	char **argv = *argvp;
++	int argc = *argcp;
++
++	nest = addattr_nest(n, 1024, IFLA_IPTUN_FAN_MAP);
++	while (argc > 0) {
++		char *colon = strchr(*argv, ':');
++
++		if (!colon)
++			break;
++		*colon = '\0';
++
++		if (get_prefix(&overlay, *argv, AF_INET))
++			invarg("invalid fan-map overlay", *argv);
++		if (get_prefix(&underlay, colon + 1, AF_INET))
++			invarg("invalid fan-map underlay", colon + 1);
++		
++		memcpy(&map.underlay, underlay.data, 4);
++		map.underlay_prefix = underlay.bitlen;
++		memcpy(&map.overlay, overlay.data, 4);
++		map.overlay_prefix = overlay.bitlen;
++
++		argc--, argv++;
++
++		addattr_l(n, 1024, IFLA_FAN_MAPPING, &map, sizeof(map));
++	}
++	addattr_nest_end(n, nest);
++
++	*argcp = argc;
++	*argvp = argv;
++	return 0;
++}
+ 
+ static int iptunnel_parse_opt(struct link_util *lu, int argc, char **argv,
+ 			      struct nlmsghdr *n)
+@@ -66,6 +102,7 @@ static int iptunnel_parse_opt(struct link_util *lu, int argc, char **argv,
+ 	__u32 link = 0;
+ 	__u32 laddr = 0;
+ 	__u32 raddr = 0;
++	__u32 underlay = 0;
+ 	__u8 ttl = 0;
+ 	__u8 tos = 0;
+ 	__u8 pmtudisc = 1;
+@@ -174,6 +211,13 @@ get_failed:
+ 				raddr = get_addr32(*argv);
+ 			else
+ 				raddr = 0;
++		} else if (strcmp(*argv, "underlay") == 0) {
++			NEXT_ARG();
++			underlay = get_addr32(*argv);
++		} else if (strcmp(*argv, "fan-map") == 0) {
++			NEXT_ARG();
++			if (fan_parse_map(&argc, &argv, n))
++				invarg("invalid fan-map", *argv);
+ 		} else if (strcmp(*argv, "local") == 0) {
+ 			NEXT_ARG();
+ 			if (strcmp(*argv, "any"))
+@@ -318,9 +362,32 @@ get_failed:
+ 		}
+ 	}
+ 
++	if (underlay)
++		addattr32(n, 1024, IFLA_IPTUN_FAN_UNDERLAY, underlay);
++
+ 	return 0;
+ }
+ 
++static void fan_print_map(FILE *f, struct rtattr *attr)
++{
++	char b1[INET_ADDRSTRLEN], b2[INET_ADDRSTRLEN];
++	struct ip_tunnel_fan_map *m;
++	struct rtattr *i;
++	int rem;
++
++	fprintf(f, "fan-map ");
++
++	rem = RTA_PAYLOAD(attr);
++	for (i = RTA_DATA(attr); RTA_OK(i, rem); i = RTA_NEXT(i, rem)) {
++		m = RTA_DATA(i);
++		fprintf(f, "%s/%d:%s/%d ",
++			rt_addr_n2a(AF_INET, sizeof(m->overlay), &m->overlay, b1, INET_ADDRSTRLEN),
++			m->overlay_prefix,
++			rt_addr_n2a(AF_INET, sizeof(m->overlay), &m->underlay, b2, INET_ADDRSTRLEN),
++			m->underlay_prefix);
++	}
++}
++
+ static void iptunnel_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
+ {
+ 	char s1[1024];
+@@ -349,6 +416,17 @@ static void iptunnel_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[
+ 
+ 	fprintf(f, "local %s ", local);
+ 
++	if (tb[IFLA_IPTUN_FAN_UNDERLAY]) {
++		unsigned addr = rta_getattr_u32(tb[IFLA_IPTUN_FAN_UNDERLAY]);
++
++		if (addr)
++			fprintf(f, "underlay %s ",
++				format_host(AF_INET, 4, &addr, s1, sizeof(s1)));
++	}
++
++	if (tb[IFLA_IPTUN_FAN_MAP])
++		fan_print_map(f, tb[IFLA_IPTUN_FAN_MAP]);
++
+ 	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);