From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [iproute2 PATCH] Add 'ip tuntap' support. Date: Sat, 19 Sep 2009 12:52:22 -0700 Message-ID: <20090919125222.5f4718f1@s6510> References: <1253378923.6317.11.camel@macbook.infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: David Woodhouse Return-path: Received: from mail.vyatta.com ([76.74.103.46]:41618 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750930AbZISTw3 (ORCPT ); Sat, 19 Sep 2009 15:52:29 -0400 In-Reply-To: <1253378923.6317.11.camel@macbook.infradead.org> Sender: netdev-owner@vger.kernel.org List-ID: On Sat, 19 Sep 2009 09:48:43 -0700 David Woodhouse wrote: > This patch provides support for 'ip tuntap', allowing creation and > deletion of persistent tun/tap devices. > > diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h > new file mode 100644 > index 0000000..915ba57 > --- /dev/null > +++ b/include/linux/if_tun.h > @@ -0,0 +1,88 @@ > +/* > + * Universal TUN/TAP device driver. > + * Copyright (C) 1999-2000 Maxim Krasnyansky > + * > + * 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. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#ifndef __IF_TUN_H > +#define __IF_TUN_H > + > +#include > +#include > + > +/* Read queue size */ > +#define TUN_READQ_SIZE 500 > + > +/* TUN device flags */ > +#define TUN_TUN_DEV 0x0001 > +#define TUN_TAP_DEV 0x0002 > +#define TUN_TYPE_MASK 0x000f > + > +#define TUN_FASYNC 0x0010 > +#define TUN_NOCHECKSUM 0x0020 > +#define TUN_NO_PI 0x0040 > +#define TUN_ONE_QUEUE 0x0080 > +#define TUN_PERSIST 0x0100 > +#define TUN_VNET_HDR 0x0200 > + > +/* Ioctl defines */ > +#define TUNSETNOCSUM _IOW('T', 200, int) > +#define TUNSETDEBUG _IOW('T', 201, int) > +#define TUNSETIFF _IOW('T', 202, int) > +#define TUNSETPERSIST _IOW('T', 203, int) > +#define TUNSETOWNER _IOW('T', 204, int) > +#define TUNSETLINK _IOW('T', 205, int) > +#define TUNSETGROUP _IOW('T', 206, int) > +#define TUNGETFEATURES _IOR('T', 207, unsigned int) > +#define TUNSETOFFLOAD _IOW('T', 208, unsigned int) > +#define TUNSETTXFILTER _IOW('T', 209, unsigned int) > +#define TUNGETIFF _IOR('T', 210, unsigned int) > +#define TUNGETSNDBUF _IOR('T', 211, int) > +#define TUNSETSNDBUF _IOW('T', 212, int) > + > +/* TUNSETIFF ifr flags */ > +#define IFF_TUN 0x0001 > +#define IFF_TAP 0x0002 > +#define IFF_NO_PI 0x1000 > +#define IFF_ONE_QUEUE 0x2000 > +#define IFF_VNET_HDR 0x4000 > +#define IFF_TUN_EXCL 0x8000 > + > +/* Features for GSO (TUNSETOFFLOAD). */ > +#define TUN_F_CSUM 0x01 /* You can hand me unchecksummed packets. */ > +#define TUN_F_TSO4 0x02 /* I can handle TSO for IPv4 packets */ > +#define TUN_F_TSO6 0x04 /* I can handle TSO for IPv6 packets */ > +#define TUN_F_TSO_ECN 0x08 /* I can handle TSO with ECN bits. */ > + > +/* Protocol info prepended to the packets (when IFF_NO_PI is not set) */ > +#define TUN_PKT_STRIP 0x0001 > +struct tun_pi { > + __u16 flags; > + __be16 proto; > +}; > + > +/* > + * Filter spec (used for SETXXFILTER ioctls) > + * This stuff is applicable only to the TAP (Ethernet) devices. > + * If the count is zero the filter is disabled and the driver accepts > + * all packets (promisc mode). > + * If the filter is enabled in order to accept broadcast packets > + * broadcast addr must be explicitly included in the addr list. > + */ > +#define TUN_FLT_ALLMULTI 0x0001 /* Accept all multicast packets */ > +struct tun_filter { > + __u16 flags; /* TUN_FLT_ flags see above */ > + __u16 count; /* Number of addresses */ > + __u8 addr[0][ETH_ALEN]; > +}; > + > +#endif /* __IF_TUN_H */ > diff --git a/ip/Makefile b/ip/Makefile > index 3c185cf..fd16fe9 100644 > --- a/ip/Makefile > +++ b/ip/Makefile > @@ -1,6 +1,6 @@ > IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o \ > rtm_map.o iptunnel.o ip6tunnel.o tunnel.o ipneigh.o ipntable.o iplink.o \ > - ipmaddr.o ipmonitor.o ipmroute.o ipprefix.o \ > + ipmaddr.o ipmonitor.o ipmroute.o ipprefix.o iptuntap.o \ > ipxfrm.o xfrm_state.o xfrm_policy.o xfrm_monitor.o \ > iplink_vlan.o link_veth.o link_gre.o iplink_can.o > > diff --git a/ip/ip.c b/ip/ip.c > index 2bd54b2..d846a76 100644 > --- a/ip/ip.c > +++ b/ip/ip.c > @@ -47,7 +47,7 @@ static void usage(void) > "Usage: ip [ OPTIONS ] OBJECT { COMMAND | help }\n" > " ip [ -force ] -batch filename\n" > "where OBJECT := { link | addr | addrlabel | route | rule | neigh | ntable |\n" > -" tunnel | maddr | mroute | monitor | xfrm }\n" > +" tunnel | tuntap | maddr | mroute | monitor | xfrm }\n" > " OPTIONS := { -V[ersion] | -s[tatistics] | -d[etails] | -r[esolve] |\n" > " -f[amily] { inet | inet6 | ipx | dnet | link } |\n" > " -o[neline] | -t[imestamp] | -b[atch] [filename] }\n"); > @@ -75,6 +75,8 @@ static const struct cmd { > { "link", do_iplink }, > { "tunnel", do_iptunnel }, > { "tunl", do_iptunnel }, > + { "tuntap", do_iptuntap }, > + { "tap", do_iptuntap }, > { "monitor", do_ipmonitor }, > { "xfrm", do_xfrm }, > { "mroute", do_multiroute }, > diff --git a/ip/ip_common.h b/ip/ip_common.h > index 273065f..c857667 100644 > --- a/ip/ip_common.h > +++ b/ip/ip_common.h > @@ -32,6 +32,7 @@ extern int do_ipneigh(int argc, char **argv); > extern int do_ipntable(int argc, char **argv); > extern int do_iptunnel(int argc, char **argv); > extern int do_ip6tunnel(int argc, char **argv); > +extern int do_iptuntap(int argc, char **argv); > extern int do_iplink(int argc, char **argv); > extern int do_ipmonitor(int argc, char **argv); > extern int do_multiaddr(int argc, char **argv); > diff --git a/ip/iptuntap.c b/ip/iptuntap.c > new file mode 100644 > index 0000000..f7f64bc > --- /dev/null > +++ b/ip/iptuntap.c > @@ -0,0 +1,321 @@ > +/* > + * iptunnel.c "ip tuntap" > + * > + * 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: David Woodhouse > + * > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "rt_names.h" > +#include "utils.h" > +#include "ip_common.h" > + > +#define TUNDEV "/dev/net/tun" > + > +static void usage(void) __attribute__((noreturn)); > + > +static void usage(void) > +{ > + fprintf(stderr, "Usage: ip tuntap { add | del } [ dev PHYS_DEV ] \n"); > + fprintf(stderr, " [ mode { tun | tap } ] [ user USER ] [ group GROUP ]\n"); > + fprintf(stderr, " [ one_queue ] [ pi ] [ vnet_hdr ]\n"); > + fprintf(stderr, "\n"); > + fprintf(stderr, "Where: USER := { STRING | NUMBER }\n"); > + fprintf(stderr, " GROUP := { STRING | NUMBER }\n"); > + exit(-1); > +} > + > +static int tap_add_ioctl(struct ifreq *ifr, uid_t uid, gid_t gid) > +{ > + int fd = open(TUNDEV, O_RDWR); > + int ret = -1; > + > + ifr->ifr_flags |= IFF_TUN_EXCL; > + > + fd = open(TUNDEV, O_RDWR); > + if (fd < 0) { > + perror("open"); > + return -1; > + } > + if (ioctl(fd, TUNSETIFF, ifr)) { > + perror("ioctl(TUNSETIFF)"); > + goto out; > + } > + if (uid != -1 && ioctl(fd, TUNSETOWNER, uid)) { > + perror("ioctl(TUNSETOWNER)"); > + goto out; > + } > + if (gid != -1 && ioctl(fd, TUNSETGROUP, gid)) { > + perror("ioctl(TUNSETGROUP)"); > + goto out; > + } > + if (ioctl(fd, TUNSETPERSIST, 1)) { > + perror("ioctl(TUNSETPERSIST)"); > + goto out; > + } > + ret = 0; > + out: > + close(fd); > + return ret; > +} > + > +static int tap_del_ioctl(struct ifreq *ifr) > +{ > + int fd = open(TUNDEV, O_RDWR); > + int ret = -1; > + > + if (fd < 0) { > + perror("open"); > + return -1; > + } > + if (ioctl(fd, TUNSETIFF, ifr)) { > + perror("ioctl(TUNSETIFF)"); > + goto out; > + } > + if (ioctl(fd, TUNSETPERSIST, 0)) { > + perror("ioctl(TUNSETPERSIST)"); > + goto out; > + } > + ret = 0; > + out: > + close(fd); > + return ret; > + > +} > +static int parse_args(int argc, char **argv, struct ifreq *ifr, uid_t *uid, gid_t *gid) > +{ > + int count = 0; > + > + memset(ifr, 0, sizeof(*ifr)); > + > + ifr->ifr_flags |= IFF_NO_PI; > + > + while (argc > 0) { > + if (matches(*argv, "mode") == 0) { > + NEXT_ARG(); > + if (matches(*argv, "tun") == 0) { > + if (ifr->ifr_flags & IFF_TAP) { > + fprintf(stderr,"You managed to ask for more than one tunnel mode.\n"); > + exit(-1); > + } > + ifr->ifr_flags |= IFF_TUN; > + } else if (matches(*argv, "tap") == 0) { > + if (ifr->ifr_flags & IFF_TUN) { > + fprintf(stderr,"You managed to ask for more than one tunnel mode.\n"); > + exit(-1); > + } > + ifr->ifr_flags |= IFF_TAP; > + } else { > + fprintf(stderr,"Cannot guess tunnel mode.\n"); > + exit(-1); > + } > + } else if (uid && matches(*argv, "user") == 0) { > + char *end; > + unsigned long user; > + > + NEXT_ARG(); > + if (**argv && ((user = strtol(*argv, &end, 10)), !*end)) > + *uid = user; > + else { > + struct passwd *pw = getpwnam(*argv); > + if (!pw) { > + fprintf(stderr, "invalid user \"%s\"\n", *argv); > + exit(-1); > + } > + *uid = pw->pw_uid; > + } > + } else if (gid && matches(*argv, "group") == 0) { > + char *end; > + unsigned long group; > + > + NEXT_ARG(); > + > + if (**argv && ((group = strtol(*argv, &end, 10)), !*end)) > + *gid = group; > + else { > + struct group *gr = getgrnam(*argv); > + if (!gr) { > + fprintf(stderr, "invalid group \"%s\"\n", *argv); > + exit(-1); > + } > + *gid = gr->gr_gid; > + } > + } else if (matches(*argv, "pi") == 0) { > + ifr->ifr_flags &= ~IFF_NO_PI; > + } else if (matches(*argv, "one_queue") == 0) { > + ifr->ifr_flags |= IFF_ONE_QUEUE; > + } else if (matches(*argv, "vnet_hdr") == 0) { > + ifr->ifr_flags |= IFF_VNET_HDR; > + } else if (matches(*argv, "dev") == 0) { > + NEXT_ARG(); > + strncpy(ifr->ifr_name, *argv, IFNAMSIZ-1); > + } else { > + if (matches(*argv, "name") == 0) { > + NEXT_ARG(); > + } else if (matches(*argv, "help") == 0) > + usage(); > + if (ifr->ifr_name[0]) > + duparg2("name", *argv); > + strncpy(ifr->ifr_name, *argv, IFNAMSIZ); > + } > + count++; > + argc--; argv++; > + } > + > + return 0; > +} > + > + > +static int do_add(int argc, char **argv) > +{ > + struct ifreq ifr; > + uid_t uid = -1; > + gid_t gid = -1; > + > + if (parse_args(argc, argv, &ifr, &uid, &gid) < 0) > + return -1; > + > + if (!(ifr.ifr_flags & TUN_TYPE_MASK)) { > + fprintf(stderr, "You failed to specify a tunnel mode\n"); > + return -1; > + } > + return tap_add_ioctl(&ifr, uid, gid); > +} > + > +static int do_del(int argc, char **argv) > +{ > + struct ifreq ifr; > + > + if (parse_args(argc, argv, &ifr, NULL, NULL) < 0) > + return -1; > + > + return tap_del_ioctl(&ifr); > +} > + > +static int read_prop(char *dev, char *prop, long *value) > +{ > + char fname[IFNAMSIZ+25], buf[80], *endp; > + ssize_t len; > + int fd; > + long result; > + > + sprintf(fname, "/sys/class/net/%s/%s", dev, prop); > + fd = open(fname, O_RDONLY); > + if (fd < 0) { > + if (strcmp(prop, "tun_flags")) > + fprintf(stderr, "open %s: %s\n", fname, > + strerror(errno)); > + return -1; > + } > + len = read(fd, buf, sizeof(buf)-1); > + close(fd); > + if (len < 0) { > + fprintf(stderr, "read %s: %s", fname, strerror(errno)); > + return -1; > + } > + > + buf[len] = 0; > + result = strtol(buf, &endp, 0); > + if (*endp != '\n') { > + fprintf(stderr, "Failed to parse %s\n", fname); > + return -1; > + } > + *value = result; > + return 0; > +} > + > +static void print_flags(long flags) > +{ > + if (flags & IFF_TUN) > + printf(" tun"); > + > + if (flags & IFF_TAP) > + printf(" tap"); > + > + if (!(flags & IFF_NO_PI)) > + printf(" pi"); > + > + if (flags & IFF_ONE_QUEUE) > + printf(" one_queue"); > + > + if (flags & IFF_VNET_HDR) > + printf(" vnet_hdr"); > + > + flags &= ~(IFF_TUN|IFF_TAP|IFF_NO_PI|IFF_ONE_QUEUE|IFF_VNET_HDR); > + if (flags) > + printf(" UNKNOWN_FLAGS:%lx", flags); > +} > + > +static int do_show(int argc, char **argv) > +{ > + DIR *dir; > + struct dirent *d; > + long flags, owner = -1, group = -1; > + > + dir = opendir("/sys/class/net"); > + if (!dir) { > + perror("opendir"); > + return -1; > + } > + while ((d = readdir(dir))) { > + if (d->d_name[0] == '.' && > + (d->d_name[1] == 0 || d->d_name[1] == '.')) > + continue; > + > + if (read_prop(d->d_name, "tun_flags", &flags)) > + continue; > + > + read_prop(d->d_name, "owner", &owner); > + read_prop(d->d_name, "group", &group); > + > + printf("%s:", d->d_name); > + print_flags(flags); > + if (owner != -1) > + printf(" user %ld", owner); > + if (group != -1) > + printf(" group %ld", group); > + printf("\n"); > + } > + return 0; > +} > + > +int do_iptuntap(int argc, char **argv) > +{ > + if (argc > 0) { > + if (matches(*argv, "add") == 0) > + return do_add(argc-1, argv+1); > + if (matches(*argv, "del") == 0) > + return do_del(argc-1, argv+1); > + if (matches(*argv, "show") == 0 || > + matches(*argv, "lst") == 0 || > + matches(*argv, "list") == 0) > + return do_show(argc-1, argv+1); > + if (matches(*argv, "help") == 0) > + usage(); > + } else > + return do_show(0, NULL); > + > + fprintf(stderr, "Command \"%s\" is unknown, try \"ip tuntap help\".\n", > + *argv); > + exit(-1); > +} > I added it, but: * cleaned up whitespace * use if_tun.h from sanitized 2.6.30 * ifdef IFF_TUN_EXCL flag, so can build with older code (currently iproute is releasing for 2.6.30)