[qemu.git] / qemu-bridge-helper.c

/*
 * QEMU Bridge Helper
 *
 * Copyright IBM, Corp. 2011
 *
 * Authors:
 * Anthony Liguori   <aliguori@us.ibm.com>
 * Richa Marwaha     <rmarwah@linux.vnet.ibm.com>
 * Corey Bryant      <coreyb@linux.vnet.ibm.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 *
 */

#include "config-host.h"

#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
#include <ctype.h>
#include <glib.h>

#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/prctl.h>

#include <net/if.h>

#include <linux/sockios.h>

#include "qemu-queue.h"

#include "net/tap-linux.h"

#ifdef CONFIG_LIBCAP
#include <cap-ng.h>
#endif

#define DEFAULT_ACL_FILE CONFIG_QEMU_CONFDIR "/bridge.conf"

enum {
    ACL_ALLOW = 0,
    ACL_ALLOW_ALL,
    ACL_DENY,
    ACL_DENY_ALL,
};

typedef struct ACLRule {
    int type;
    char iface[IFNAMSIZ];
    QSIMPLEQ_ENTRY(ACLRule) entry;
} ACLRule;

typedef QSIMPLEQ_HEAD(ACLList, ACLRule) ACLList;

static void usage(void)
{
    fprintf(stderr,
            "Usage: qemu-bridge-helper [--use-vnet] --br=bridge --fd=unixfd\n");
}

static int parse_acl_file(const char *filename, ACLList *acl_list)
{
    FILE *f;
    char line[4096];
    ACLRule *acl_rule;

    f = fopen(filename, "r");
    if (f == NULL) {
        return -1;
    }

    while (fgets(line, sizeof(line), f) != NULL) {
        char *ptr = line;
        char *cmd, *arg, *argend;

        while (isspace(*ptr)) {
            ptr++;
        }

        /* skip comments and empty lines */
        if (*ptr == '#' || *ptr == 0) {
            continue;
        }

        cmd = ptr;
        arg = strchr(cmd, ' ');
        if (arg == NULL) {
            arg = strchr(cmd, '\t');
        }

        if (arg == NULL) {
            fprintf(stderr, "Invalid config line:\n  %s\n", line);
            fclose(f);
            errno = EINVAL;
            return -1;
        }

        *arg = 0;
        arg++;
        while (isspace(*arg)) {
            arg++;
        }

        argend = arg + strlen(arg);
        while (arg != argend && isspace(*(argend - 1))) {
            argend--;
        }
        *argend = 0;

        if (strcmp(cmd, "deny") == 0) {
            acl_rule = g_malloc(sizeof(*acl_rule));
            if (strcmp(arg, "all") == 0) {
                acl_rule->type = ACL_DENY_ALL;
            } else {
                acl_rule->type = ACL_DENY;
                snprintf(acl_rule->iface, IFNAMSIZ, "%s", arg);
            }
            QSIMPLEQ_INSERT_TAIL(acl_list, acl_rule, entry);
        } else if (strcmp(cmd, "allow") == 0) {
            acl_rule = g_malloc(sizeof(*acl_rule));
            if (strcmp(arg, "all") == 0) {
                acl_rule->type = ACL_ALLOW_ALL;
            } else {
                acl_rule->type = ACL_ALLOW;
                snprintf(acl_rule->iface, IFNAMSIZ, "%s", arg);
            }
            QSIMPLEQ_INSERT_TAIL(acl_list, acl_rule, entry);
        } else if (strcmp(cmd, "include") == 0) {
            /* ignore errors */
            parse_acl_file(arg, acl_list);
        } else {
            fprintf(stderr, "Unknown command `%s'\n", cmd);
            fclose(f);
            errno = EINVAL;
            return -1;
        }
    }

    fclose(f);

    return 0;
}

static bool has_vnet_hdr(int fd)
{
    unsigned int features = 0;

    if (ioctl(fd, TUNGETFEATURES, &features) == -1) {
        return false;
    }

    if (!(features & IFF_VNET_HDR)) {
        return false;
    }

    return true;
}

static void prep_ifreq(struct ifreq *ifr, const char *ifname)
{
    memset(ifr, 0, sizeof(*ifr));
    snprintf(ifr->ifr_name, IFNAMSIZ, "%s", ifname);
}

static int send_fd(int c, int fd)
{
    char msgbuf[CMSG_SPACE(sizeof(fd))];
    struct msghdr msg = {
        .msg_control = msgbuf,
        .msg_controllen = sizeof(msgbuf),
    };
    struct cmsghdr *cmsg;
    struct iovec iov;
    char req[1] = { 0x00 };

    cmsg = CMSG_FIRSTHDR(&msg);
    cmsg->cmsg_level = SOL_SOCKET;
    cmsg->cmsg_type = SCM_RIGHTS;
    cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
    msg.msg_controllen = cmsg->cmsg_len;

    iov.iov_base = req;
    iov.iov_len = sizeof(req);

    msg.msg_iov = &iov;
    msg.msg_iovlen = 1;
    memcpy(CMSG_DATA(cmsg), &fd, sizeof(fd));

    return sendmsg(c, &msg, 0);
}

#ifdef CONFIG_LIBCAP
static int drop_privileges(void)
{
    /* clear all capabilities */
    capng_clear(CAPNG_SELECT_BOTH);

    if (capng_update(CAPNG_ADD, CAPNG_EFFECTIVE | CAPNG_PERMITTED,
                     CAP_NET_ADMIN) < 0) {
        return -1;
    }

    /* change to calling user's real uid and gid, retaining supplemental
     * groups and CAP_NET_ADMIN */
    if (capng_change_id(getuid(), getgid(), CAPNG_CLEAR_BOUNDING)) {
        return -1;
    }

    return 0;
}
#endif

int main(int argc, char **argv)
{
    struct ifreq ifr;
    int fd, ctlfd, unixfd = -1;
    int use_vnet = 0;
    int mtu;
    const char *bridge = NULL;
    char iface[IFNAMSIZ];
    int index;
    ACLRule *acl_rule;
    ACLList acl_list;
    int access_allowed, access_denied;
    int ret = EXIT_SUCCESS;

#ifdef CONFIG_LIBCAP
    /* if we're run from an suid binary, immediately drop privileges preserving
     * cap_net_admin */
    if (geteuid() == 0 && getuid() != geteuid()) {
        if (drop_privileges() == -1) {
            fprintf(stderr, "failed to drop privileges\n");
            return 1;
        }
    }
#endif

    /* parse arguments */
    for (index = 1; index < argc; index++) {
        if (strcmp(argv[index], "--use-vnet") == 0) {
            use_vnet = 1;
        } else if (strncmp(argv[index], "--br=", 5) == 0) {
            bridge = &argv[index][5];
        } else if (strncmp(argv[index], "--fd=", 5) == 0) {
            unixfd = atoi(&argv[index][5]);
        } else {
            usage();
            return EXIT_FAILURE;
        }
    }

    if (bridge == NULL || unixfd == -1) {
        usage();
        return EXIT_FAILURE;
    }

    /* parse default acl file */
    QSIMPLEQ_INIT(&acl_list);
    if (parse_acl_file(DEFAULT_ACL_FILE, &acl_list) == -1) {
        fprintf(stderr, "failed to parse default acl file `%s'\n",
                DEFAULT_ACL_FILE);
        ret = EXIT_FAILURE;
        goto cleanup;
    }

    /* validate bridge against acl -- default policy is to deny
     * according acl policy if we have a deny and allow both
     * then deny should always win over allow
     */
    access_allowed = 0;
    access_denied = 0;
    QSIMPLEQ_FOREACH(acl_rule, &acl_list, entry) {
        switch (acl_rule->type) {
        case ACL_ALLOW_ALL:
            access_allowed = 1;
            break;
        case ACL_ALLOW:
            if (strcmp(bridge, acl_rule->iface) == 0) {
                access_allowed = 1;
            }
            break;
        case ACL_DENY_ALL:
            access_denied = 1;
            break;
        case ACL_DENY:
            if (strcmp(bridge, acl_rule->iface) == 0) {
                access_denied = 1;
            }
            break;
        }
    }

    if ((access_allowed == 0) || (access_denied == 1)) {
        fprintf(stderr, "access denied by acl file\n");
        ret = EXIT_FAILURE;
        goto cleanup;
    }

    /* open a socket to use to control the network interfaces */
    ctlfd = socket(AF_INET, SOCK_STREAM, 0);
    if (ctlfd == -1) {
        fprintf(stderr, "failed to open control socket: %s\n", strerror(errno));
        ret = EXIT_FAILURE;
        goto cleanup;
    }

    /* open the tap device */
    fd = open("/dev/net/tun", O_RDWR);
    if (fd == -1) {
        fprintf(stderr, "failed to open /dev/net/tun: %s\n", strerror(errno));
        ret = EXIT_FAILURE;
        goto cleanup;
    }

    /* request a tap device, disable PI, and add vnet header support if
     * requested and it's available. */
    prep_ifreq(&ifr, "tap%d");
    ifr.ifr_flags = IFF_TAP|IFF_NO_PI;
    if (use_vnet && has_vnet_hdr(fd)) {
        ifr.ifr_flags |= IFF_VNET_HDR;
    }

    if (ioctl(fd, TUNSETIFF, &ifr) == -1) {
        fprintf(stderr, "failed to create tun device: %s\n", strerror(errno));
        ret = EXIT_FAILURE;
        goto cleanup;
    }

    /* save tap device name */
    snprintf(iface, sizeof(iface), "%s", ifr.ifr_name);

    /* get the mtu of the bridge */
    prep_ifreq(&ifr, bridge);
    if (ioctl(ctlfd, SIOCGIFMTU, &ifr) == -1) {
        fprintf(stderr, "failed to get mtu of bridge `%s': %s\n",
                bridge, strerror(errno));
        ret = EXIT_FAILURE;
        goto cleanup;
    }

    /* save mtu */
    mtu = ifr.ifr_mtu;

    /* set the mtu of the interface based on the bridge */
    prep_ifreq(&ifr, iface);
    ifr.ifr_mtu = mtu;
    if (ioctl(ctlfd, SIOCSIFMTU, &ifr) == -1) {
        fprintf(stderr, "failed to set mtu of device `%s' to %d: %s\n",
                iface, mtu, strerror(errno));
        ret = EXIT_FAILURE;
        goto cleanup;
    }

    /* add the interface to the bridge */
    prep_ifreq(&ifr, bridge);
    ifr.ifr_ifindex = if_nametoindex(iface);

    if (ioctl(ctlfd, SIOCBRADDIF, &ifr) == -1) {
        fprintf(stderr, "failed to add interface `%s' to bridge `%s': %s\n",
                iface, bridge, strerror(errno));
        ret = EXIT_FAILURE;
        goto cleanup;
    }

    /* bring the interface up */
    prep_ifreq(&ifr, iface);
    if (ioctl(ctlfd, SIOCGIFFLAGS, &ifr) == -1) {
        fprintf(stderr, "failed to get interface flags for `%s': %s\n",
                iface, strerror(errno));
        ret = EXIT_FAILURE;
        goto cleanup;
    }

    ifr.ifr_flags |= IFF_UP;
    if (ioctl(ctlfd, SIOCSIFFLAGS, &ifr) == -1) {
        fprintf(stderr, "failed to bring up interface `%s': %s\n",
                iface, strerror(errno));
        ret = EXIT_FAILURE;
        goto cleanup;
    }

    /* write fd to the domain socket */
    if (send_fd(unixfd, fd) == -1) {
        fprintf(stderr, "failed to write fd to unix socket: %s\n",
                strerror(errno));
        ret = EXIT_FAILURE;
        goto cleanup;
    }

    /* ... */

    /* profit! */

cleanup:

    while ((acl_rule = QSIMPLEQ_FIRST(&acl_list)) != NULL) {
        QSIMPLEQ_REMOVE_HEAD(&acl_list, entry);
        g_free(acl_rule);
    }

    return ret;
}
Commit	Line	Data
7b93fadf CB	1	/*
	2	* QEMU Bridge Helper
	3	*
	4	* Copyright IBM, Corp. 2011
	5	*
	6	* Authors:
	7	* Anthony Liguori <aliguori@us.ibm.com>
	8	* Richa Marwaha <rmarwah@linux.vnet.ibm.com>
	9	* Corey Bryant <coreyb@linux.vnet.ibm.com>
	10	*
	11	* This work is licensed under the terms of the GNU GPL, version 2. See
	12	* the COPYING file in the top-level directory.
	13	*
	14	*/
	15
	16	#include "config-host.h"
	17
	18	#include <stdio.h>
	19	#include <errno.h>
	20	#include <fcntl.h>
	21	#include <unistd.h>
	22	#include <string.h>
	23	#include <stdlib.h>
	24	#include <stdbool.h>
	25	#include <ctype.h>
bdef79a2	26	#include <glib.h>
7b93fadf CB	27
	28	#include <sys/types.h>
	29	#include <sys/ioctl.h>
	30	#include <sys/socket.h>
	31	#include <sys/un.h>
	32	#include <sys/prctl.h>
	33
	34	#include <net/if.h>
	35
	36	#include <linux/sockios.h>
	37
bdef79a2 CB	38	#include "qemu-queue.h"
bdef79a2 CB	39
7b93fadf CB	40	#include "net/tap-linux.h"
7b93fadf CB	41
47e98658 CB	42	#ifdef CONFIG_LIBCAP
	43	#include <cap-ng.h>
	44	#endif
	45
bdef79a2 CB	46	#define DEFAULT_ACL_FILE CONFIG_QEMU_CONFDIR "/bridge.conf"
	47
	48	enum {
	49	ACL_ALLOW = 0,
	50	ACL_ALLOW_ALL,
	51	ACL_DENY,
	52	ACL_DENY_ALL,
	53	};
	54
	55	typedef struct ACLRule {
	56	int type;
	57	char iface[IFNAMSIZ];
	58	QSIMPLEQ_ENTRY(ACLRule) entry;
	59	} ACLRule;
	60
	61	typedef QSIMPLEQ_HEAD(ACLList, ACLRule) ACLList;
	62
7b93fadf CB	63	static void usage(void)
	64	{
	65	fprintf(stderr,
	66	"Usage: qemu-bridge-helper [--use-vnet] --br=bridge --fd=unixfd\n");
	67	}
	68
bdef79a2 CB	69	static int parse_acl_file(const char filename, ACLList acl_list)
	70	{
	71	FILE *f;
	72	char line[4096];
	73	ACLRule *acl_rule;
	74
	75	f = fopen(filename, "r");
	76	if (f == NULL) {
	77	return -1;
	78	}
	79
	80	while (fgets(line, sizeof(line), f) != NULL) {
	81	char *ptr = line;
	82	char cmd, arg, *argend;
	83
	84	while (isspace(*ptr)) {
	85	ptr++;
	86	}
	87
	88	/* skip comments and empty lines */
	89	if (ptr == '#' \|\| ptr == 0) {
	90	continue;
	91	}
	92
	93	cmd = ptr;
	94	arg = strchr(cmd, ' ');
	95	if (arg == NULL) {
	96	arg = strchr(cmd, '\t');
	97	}
	98
	99	if (arg == NULL) {
	100	fprintf(stderr, "Invalid config line:\n %s\n", line);
	101	fclose(f);
	102	errno = EINVAL;
	103	return -1;
	104	}
	105
	106	*arg = 0;
	107	arg++;
	108	while (isspace(*arg)) {
	109	arg++;
	110	}
	111
	112	argend = arg + strlen(arg);
	113	while (arg != argend && isspace(*(argend - 1))) {
	114	argend--;
	115	}
	116	*argend = 0;
	117
	118	if (strcmp(cmd, "deny") == 0) {
	119	acl_rule = g_malloc(sizeof(*acl_rule));
	120	if (strcmp(arg, "all") == 0) {
	121	acl_rule->type = ACL_DENY_ALL;
	122	} else {
	123	acl_rule->type = ACL_DENY;
	124	snprintf(acl_rule->iface, IFNAMSIZ, "%s", arg);
	125	}
	126	QSIMPLEQ_INSERT_TAIL(acl_list, acl_rule, entry);
	127	} else if (strcmp(cmd, "allow") == 0) {
	128	acl_rule = g_malloc(sizeof(*acl_rule));
	129	if (strcmp(arg, "all") == 0) {
	130	acl_rule->type = ACL_ALLOW_ALL;
	131	} else {
	132	acl_rule->type = ACL_ALLOW;
133	snprintf(acl_rule->iface, IFNAMSIZ, "%s", arg);
134	}
135	QSIMPLEQ_INSERT_TAIL(acl_list, acl_rule, entry);
136	} else if (strcmp(cmd, "include") == 0) {
137	/* ignore errors */
138	parse_acl_file(arg, acl_list);
139	} else {
140	fprintf(stderr, "Unknown command `%s'\n", cmd);
141	fclose(f);
142	errno = EINVAL;
143	return -1;
144	}
145	}
146
147	fclose(f);
148
149	return 0;
150	}
151
7b93fadf CB	152	static bool has_vnet_hdr(int fd)
	153	{
	154	unsigned int features = 0;
	155
	156	if (ioctl(fd, TUNGETFEATURES, &features) == -1) {
	157	return false;
	158	}
	159
	160	if (!(features & IFF_VNET_HDR)) {
	161	return false;
	162	}
	163
	164	return true;
	165	}
	166
	167	static void prep_ifreq(struct ifreq ifr, const char ifname)
	168	{
	169	memset(ifr, 0, sizeof(*ifr));
	170	snprintf(ifr->ifr_name, IFNAMSIZ, "%s", ifname);
	171	}
	172
	173	static int send_fd(int c, int fd)
	174	{
	175	char msgbuf[CMSG_SPACE(sizeof(fd))];
	176	struct msghdr msg = {
	177	.msg_control = msgbuf,
	178	.msg_controllen = sizeof(msgbuf),
	179	};
	180	struct cmsghdr *cmsg;
	181	struct iovec iov;
	182	char req[1] = { 0x00 };
	183
	184	cmsg = CMSG_FIRSTHDR(&msg);
	185	cmsg->cmsg_level = SOL_SOCKET;
	186	cmsg->cmsg_type = SCM_RIGHTS;
	187	cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
	188	msg.msg_controllen = cmsg->cmsg_len;
	189
	190	iov.iov_base = req;
	191	iov.iov_len = sizeof(req);
	192
	193	msg.msg_iov = &iov;
	194	msg.msg_iovlen = 1;
	195	memcpy(CMSG_DATA(cmsg), &fd, sizeof(fd));
	196
	197	return sendmsg(c, &msg, 0);
	198	}
	199
47e98658 CB	200	#ifdef CONFIG_LIBCAP
	201	static int drop_privileges(void)
	202	{
	203	/* clear all capabilities */
	204	capng_clear(CAPNG_SELECT_BOTH);
	205
	206	if (capng_update(CAPNG_ADD, CAPNG_EFFECTIVE \| CAPNG_PERMITTED,
	207	CAP_NET_ADMIN) < 0) {
	208	return -1;
	209	}
	210
	211	/* change to calling user's real uid and gid, retaining supplemental
	212	* groups and CAP_NET_ADMIN */
	213	if (capng_change_id(getuid(), getgid(), CAPNG_CLEAR_BOUNDING)) {
	214	return -1;
	215	}
	216
	217	return 0;
	218	}
	219	#endif
	220
7b93fadf CB	221	int main(int argc, char **argv)
	222	{
	223	struct ifreq ifr;
	224	int fd, ctlfd, unixfd = -1;
	225	int use_vnet = 0;
	226	int mtu;
	227	const char *bridge = NULL;
	228	char iface[IFNAMSIZ];
	229	int index;
bdef79a2 CB	230	ACLRule *acl_rule;
	231	ACLList acl_list;
	232	int access_allowed, access_denied;
7b93fadf CB	233	int ret = EXIT_SUCCESS;
7b93fadf CB	234
47e98658 CB	235	#ifdef CONFIG_LIBCAP
	236	/* if we're run from an suid binary, immediately drop privileges preserving
	237	* cap_net_admin */
	238	if (geteuid() == 0 && getuid() != geteuid()) {
	239	if (drop_privileges() == -1) {
	240	fprintf(stderr, "failed to drop privileges\n");
	241	return 1;
	242	}
	243	}
	244	#endif
	245
7b93fadf CB	246	/* parse arguments */
	247	for (index = 1; index < argc; index++) {
	248	if (strcmp(argv[index], "--use-vnet") == 0) {
	249	use_vnet = 1;
	250	} else if (strncmp(argv[index], "--br=", 5) == 0) {
	251	bridge = &argv[index][5];
	252	} else if (strncmp(argv[index], "--fd=", 5) == 0) {
	253	unixfd = atoi(&argv[index][5]);
	254	} else {
	255	usage();
	256	return EXIT_FAILURE;
	257	}
	258	}
	259
	260	if (bridge == NULL \|\| unixfd == -1) {
	261	usage();
	262	return EXIT_FAILURE;
	263	}
	264
bdef79a2 CB	265	/* parse default acl file */
	266	QSIMPLEQ_INIT(&acl_list);
	267	if (parse_acl_file(DEFAULT_ACL_FILE, &acl_list) == -1) {
	268	fprintf(stderr, "failed to parse default acl file `%s'\n",
	269	DEFAULT_ACL_FILE);
	270	ret = EXIT_FAILURE;
	271	goto cleanup;
	272	}
	273
	274	/* validate bridge against acl -- default policy is to deny
	275	* according acl policy if we have a deny and allow both
	276	* then deny should always win over allow
	277	*/
	278	access_allowed = 0;
	279	access_denied = 0;
	280	QSIMPLEQ_FOREACH(acl_rule, &acl_list, entry) {
	281	switch (acl_rule->type) {
	282	case ACL_ALLOW_ALL:
	283	access_allowed = 1;
	284	break;
	285	case ACL_ALLOW:
	286	if (strcmp(bridge, acl_rule->iface) == 0) {
	287	access_allowed = 1;
	288	}
	289	break;
	290	case ACL_DENY_ALL:
	291	access_denied = 1;
	292	break;
	293	case ACL_DENY:
	294	if (strcmp(bridge, acl_rule->iface) == 0) {
	295	access_denied = 1;
	296	}
	297	break;
	298	}
	299	}
	300
	301	if ((access_allowed == 0) \|\| (access_denied == 1)) {
	302	fprintf(stderr, "access denied by acl file\n");
	303	ret = EXIT_FAILURE;
	304	goto cleanup;
	305	}
	306
7b93fadf CB	307	/* open a socket to use to control the network interfaces */
	308	ctlfd = socket(AF_INET, SOCK_STREAM, 0);
	309	if (ctlfd == -1) {
	310	fprintf(stderr, "failed to open control socket: %s\n", strerror(errno));
	311	ret = EXIT_FAILURE;
	312	goto cleanup;
	313	}
	314
	315	/* open the tap device */
	316	fd = open("/dev/net/tun", O_RDWR);
	317	if (fd == -1) {
	318	fprintf(stderr, "failed to open /dev/net/tun: %s\n", strerror(errno));
	319	ret = EXIT_FAILURE;
	320	goto cleanup;
	321	}
	322
	323	/* request a tap device, disable PI, and add vnet header support if
	324	* requested and it's available. */
	325	prep_ifreq(&ifr, "tap%d");
	326	ifr.ifr_flags = IFF_TAP\|IFF_NO_PI;
	327	if (use_vnet && has_vnet_hdr(fd)) {
	328	ifr.ifr_flags \|= IFF_VNET_HDR;
	329	}
	330
	331	if (ioctl(fd, TUNSETIFF, &ifr) == -1) {
	332	fprintf(stderr, "failed to create tun device: %s\n", strerror(errno));
	333	ret = EXIT_FAILURE;
	334	goto cleanup;
	335	}
	336
	337	/* save tap device name */
	338	snprintf(iface, sizeof(iface), "%s", ifr.ifr_name);
	339
	340	/* get the mtu of the bridge */
	341	prep_ifreq(&ifr, bridge);
	342	if (ioctl(ctlfd, SIOCGIFMTU, &ifr) == -1) {
	343	fprintf(stderr, "failed to get mtu of bridge `%s': %s\n",
	344	bridge, strerror(errno));
	345	ret = EXIT_FAILURE;
	346	goto cleanup;
	347	}
	348
	349	/* save mtu */
	350	mtu = ifr.ifr_mtu;
	351
	352	/* set the mtu of the interface based on the bridge */
	353	prep_ifreq(&ifr, iface);
	354	ifr.ifr_mtu = mtu;
	355	if (ioctl(ctlfd, SIOCSIFMTU, &ifr) == -1) {
	356	fprintf(stderr, "failed to set mtu of device `%s' to %d: %s\n",
	357	iface, mtu, strerror(errno));
	358	ret = EXIT_FAILURE;
	359	goto cleanup;
	360	}
	361
	362	/* add the interface to the bridge */
	363	prep_ifreq(&ifr, bridge);
	364	ifr.ifr_ifindex = if_nametoindex(iface);
	365
	366	if (ioctl(ctlfd, SIOCBRADDIF, &ifr) == -1) {
	367	fprintf(stderr, "failed to add interface `%s' to bridge `%s': %s\n",
	368	iface, bridge, strerror(errno));
	369	ret = EXIT_FAILURE;
	370	goto cleanup;
371	}
372
373	/* bring the interface up */
374	prep_ifreq(&ifr, iface);
375	if (ioctl(ctlfd, SIOCGIFFLAGS, &ifr) == -1) {
376	fprintf(stderr, "failed to get interface flags for `%s': %s\n",
377	iface, strerror(errno));
378	ret = EXIT_FAILURE;
379	goto cleanup;
380	}
381
382	ifr.ifr_flags \|= IFF_UP;
383	if (ioctl(ctlfd, SIOCSIFFLAGS, &ifr) == -1) {
384	fprintf(stderr, "failed to bring up interface `%s': %s\n",
385	iface, strerror(errno));
386	ret = EXIT_FAILURE;
387	goto cleanup;
388	}
389
390	/* write fd to the domain socket */
391	if (send_fd(unixfd, fd) == -1) {
392	fprintf(stderr, "failed to write fd to unix socket: %s\n",
393	strerror(errno));
394	ret = EXIT_FAILURE;
395	goto cleanup;
396	}
397
398	/* ... */
399
400	/* profit! */
401
402	cleanup:
403
bdef79a2 CB	404	while ((acl_rule = QSIMPLEQ_FIRST(&acl_list)) != NULL) {
	405	QSIMPLEQ_REMOVE_HEAD(&acl_list, entry);
	406	g_free(acl_rule);
	407	}
	408
7b93fadf CB	409	return ret;
7b93fadf CB	410	}