ifc_utils.c revision 7c3d1c291ab5f9efb2efcfd5def1baeea1255917 
1/*
2 * Copyright 2008, The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <stdio.h>
18#include <stdlib.h>
19#include <unistd.h>
20#include <string.h>
21#include <errno.h>
22
23#include <sys/socket.h>
24#include <sys/select.h>
25#include <sys/types.h>
26#include <netinet/in.h>
27#include <arpa/inet.h>
28#include <net/if.h>
29#include <netdb.h>
30
31#include <linux/if.h>
32#include <linux/if_ether.h>
33#include <linux/if_arp.h>
34#include <linux/netlink.h>
35#include <linux/route.h>
36#include <linux/ipv6_route.h>
37#include <linux/rtnetlink.h>
38#include <linux/sockios.h>
39
40#include "netutils/ifc.h"
41
42#ifdef ANDROID
43#define LOG_TAG "NetUtils"
44#include <cutils/log.h>
45#include <cutils/properties.h>
46#else
47#include <stdio.h>
48#include <string.h>
49#define ALOGD printf
50#define ALOGW printf
51#endif
52
53static int ifc_ctl_sock = -1;
54static int ifc_ctl_sock6 = -1;
55void printerr(char *fmt, ...);
56
57#define DBG 0
58#define INET_ADDRLEN 4
59#define INET6_ADDRLEN 16
60
61in_addr_t prefixLengthToIpv4Netmask(int prefix_length)
62{
63    in_addr_t mask = 0;
64
65    // C99 (6.5.7): shifts of 32 bits have undefined results
66    if (prefix_length <= 0 || prefix_length > 32) {
67        return 0;
68    }
69
70    mask = ~mask << (32 - prefix_length);
71    mask = htonl(mask);
72
73    return mask;
74}
75
76int ipv4NetmaskToPrefixLength(in_addr_t mask)
77{
78    mask = ntohl(mask);
79    int prefixLength = 0;
80    uint32_t m = (uint32_t)mask;
81    while (m & 0x80000000) {
82        prefixLength++;
83        m = m << 1;
84    }
85    return prefixLength;
86}
87
88static const char *ipaddr_to_string(in_addr_t addr)
89{
90    struct in_addr in_addr;
91
92    in_addr.s_addr = addr;
93    return inet_ntoa(in_addr);
94}
95
96int string_to_ip(const char *string, struct sockaddr_storage *ss) {
97    struct addrinfo hints, *ai;
98    int ret;
99
100    if (ss == NULL) {
101        return -EFAULT;
102    }
103
104    memset(&hints, 0, sizeof(hints));
105    hints.ai_family = AF_UNSPEC;
106    hints.ai_flags = AI_NUMERICHOST;
107    hints.ai_socktype = SOCK_DGRAM;
108
109    ret = getaddrinfo(string, NULL, &hints, &ai);
110    if (ret == 0) {
111        memcpy(ss, ai->ai_addr, ai->ai_addrlen);
112        freeaddrinfo(ai);
113    }
114
115    return ret;
116}
117
118int ifc_init(void)
119{
120    int ret;
121    if (ifc_ctl_sock == -1) {
122        ifc_ctl_sock = socket(AF_INET, SOCK_DGRAM, 0);
123        if (ifc_ctl_sock < 0) {
124            printerr("socket() failed: %s\n", strerror(errno));
125        }
126    }
127
128    ret = ifc_ctl_sock < 0 ? -1 : 0;
129    if (DBG) printerr("ifc_init_returning %d", ret);
130    return ret;
131}
132
133int ifc_init6(void)
134{
135    if (ifc_ctl_sock6 == -1) {
136        ifc_ctl_sock6 = socket(AF_INET6, SOCK_DGRAM, 0);
137        if (ifc_ctl_sock6 < 0) {
138            printerr("socket() failed: %s\n", strerror(errno));
139        }
140    }
141    return ifc_ctl_sock6 < 0 ? -1 : 0;
142}
143
144void ifc_close(void)
145{
146    if (DBG) printerr("ifc_close");
147    if (ifc_ctl_sock != -1) {
148        (void)close(ifc_ctl_sock);
149        ifc_ctl_sock = -1;
150    }
151}
152
153void ifc_close6(void)
154{
155    if (ifc_ctl_sock6 != -1) {
156        (void)close(ifc_ctl_sock6);
157        ifc_ctl_sock6 = -1;
158    }
159}
160
161static void ifc_init_ifr(const char *name, struct ifreq *ifr)
162{
163    memset(ifr, 0, sizeof(struct ifreq));
164    strncpy(ifr->ifr_name, name, IFNAMSIZ);
165    ifr->ifr_name[IFNAMSIZ - 1] = 0;
166}
167
168int ifc_get_hwaddr(const char *name, void *ptr)
169{
170    int r;
171    struct ifreq ifr;
172    ifc_init_ifr(name, &ifr);
173
174    r = ioctl(ifc_ctl_sock, SIOCGIFHWADDR, &ifr);
175    if(r < 0) return -1;
176
177    memcpy(ptr, &ifr.ifr_hwaddr.sa_data, ETH_ALEN);
178    return 0;
179}
180
181int ifc_get_ifindex(const char *name, int *if_indexp)
182{
183    int r;
184    struct ifreq ifr;
185    ifc_init_ifr(name, &ifr);
186
187    r = ioctl(ifc_ctl_sock, SIOCGIFINDEX, &ifr);
188    if(r < 0) return -1;
189
190    *if_indexp = ifr.ifr_ifindex;
191    return 0;
192}
193
194static int ifc_set_flags(const char *name, unsigned set, unsigned clr)
195{
196    struct ifreq ifr;
197    ifc_init_ifr(name, &ifr);
198
199    if(ioctl(ifc_ctl_sock, SIOCGIFFLAGS, &ifr) < 0) return -1;
200    ifr.ifr_flags = (ifr.ifr_flags & (~clr)) | set;
201    return ioctl(ifc_ctl_sock, SIOCSIFFLAGS, &ifr);
202}
203
204int ifc_up(const char *name)
205{
206    int ret = ifc_set_flags(name, IFF_UP, 0);
207    if (DBG) printerr("ifc_up(%s) = %d", name, ret);
208    return ret;
209}
210
211int ifc_down(const char *name)
212{
213    int ret = ifc_set_flags(name, 0, IFF_UP);
214    if (DBG) printerr("ifc_down(%s) = %d", name, ret);
215    return ret;
216}
217
218static void init_sockaddr_in(struct sockaddr *sa, in_addr_t addr)
219{
220    struct sockaddr_in *sin = (struct sockaddr_in *) sa;
221    sin->sin_family = AF_INET;
222    sin->sin_port = 0;
223    sin->sin_addr.s_addr = addr;
224}
225
226int ifc_set_addr(const char *name, in_addr_t addr)
227{
228    struct ifreq ifr;
229    int ret;
230
231    ifc_init_ifr(name, &ifr);
232    init_sockaddr_in(&ifr.ifr_addr, addr);
233
234    ret = ioctl(ifc_ctl_sock, SIOCSIFADDR, &ifr);
235    if (DBG) printerr("ifc_set_addr(%s, xx) = %d", name, ret);
236    return ret;
237}
238
239/*
240 * Adds or deletes an IP address on an interface.
241 *
242 * Action is one of:
243 * - RTM_NEWADDR (to add a new address)
244 * - RTM_DELADDR (to delete an existing address)
245 *
246 * Returns zero on success and negative errno on failure.
247 */
248int ifc_act_on_address(int action, const char *name, const char *address,
249                       int prefixlen) {
250    int ifindex, s, len, ret;
251    struct sockaddr_storage ss;
252    void *addr;
253    size_t addrlen;
254    struct {
255        struct nlmsghdr n;
256        struct ifaddrmsg r;
257        // Allow for IPv6 address, headers, and padding.
258        char attrbuf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
259                     NLMSG_ALIGN(sizeof(struct rtattr)) +
260                     NLMSG_ALIGN(INET6_ADDRLEN)];
261    } req;
262    struct rtattr *rta;
263    struct nlmsghdr *nh;
264    struct nlmsgerr *err;
265    char buf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
266             NLMSG_ALIGN(sizeof(struct nlmsgerr)) +
267             NLMSG_ALIGN(sizeof(struct nlmsghdr))];
268
269    // Get interface ID.
270    ifindex = if_nametoindex(name);
271    if (ifindex == 0) {
272        return -errno;
273    }
274
275    // Convert string representation to sockaddr_storage.
276    ret = string_to_ip(address, &ss);
277    if (ret) {
278        return ret;
279    }
280
281    // Determine address type and length.
282    if (ss.ss_family == AF_INET) {
283        struct sockaddr_in *sin = (struct sockaddr_in *) &ss;
284        addr = &sin->sin_addr;
285        addrlen = INET_ADDRLEN;
286    } else if (ss.ss_family == AF_INET6) {
287        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) &ss;
288        addr = &sin6->sin6_addr;
289        addrlen = INET6_ADDRLEN;
290    } else {
291        return -EAFNOSUPPORT;
292    }
293
294    // Fill in netlink structures.
295    memset(&req, 0, sizeof(req));
296
297    // Netlink message header.
298    req.n.nlmsg_len = NLMSG_LENGTH(sizeof(req.r));
299    req.n.nlmsg_type = action;
300    req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
301    req.n.nlmsg_pid = getpid();
302
303    // Interface address message header.
304    req.r.ifa_family = ss.ss_family;
305    req.r.ifa_prefixlen = prefixlen;
306    req.r.ifa_index = ifindex;
307
308    // Routing attribute. Contains the actual IP address.
309    rta = (struct rtattr *) (((char *) &req) + NLMSG_ALIGN(req.n.nlmsg_len));
310    rta->rta_type = IFA_LOCAL;
311    rta->rta_len = RTA_LENGTH(addrlen);
312    req.n.nlmsg_len = NLMSG_ALIGN(req.n.nlmsg_len) + RTA_LENGTH(addrlen);
313    memcpy(RTA_DATA(rta), addr, addrlen);
314
315    s = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
316    if (send(s, &req, req.n.nlmsg_len, 0) < 0) {
317        close(s);
318        return -errno;
319    }
320
321    len = recv(s, buf, sizeof(buf), 0);
322    close(s);
323    if (len < 0) {
324        return -errno;
325    }
326
327    // Parse the acknowledgement to find the return code.
328    nh = (struct nlmsghdr *) buf;
329    if (!NLMSG_OK(nh, (unsigned) len) || nh->nlmsg_type != NLMSG_ERROR) {
330        return -EINVAL;
331    }
332    err = NLMSG_DATA(nh);
333
334    // Return code is negative errno.
335    return err->error;
336}
337
338int ifc_add_address(const char *name, const char *address, int prefixlen) {
339    return ifc_act_on_address(RTM_NEWADDR, name, address, prefixlen);
340}
341
342int ifc_del_address(const char *name, const char * address, int prefixlen) {
343    return ifc_act_on_address(RTM_DELADDR, name, address, prefixlen);
344}
345
346/*
347 * Clears IPv6 addresses on the specified interface.
348 */
349int ifc_clear_ipv6_addresses(const char *name) {
350    char rawaddrstr[INET6_ADDRSTRLEN], addrstr[INET6_ADDRSTRLEN];
351    unsigned int prefixlen;
352    int lasterror = 0, i, j, ret;
353    char ifname[64];  // Currently, IFNAMSIZ = 16.
354    FILE *f = fopen("/proc/net/if_inet6", "r");
355    if (!f) {
356        return -errno;
357    }
358
359    // Format:
360    // 20010db8000a0001fc446aa4b5b347ed 03 40 00 01    wlan0
361    while (fscanf(f, "%32s %*02x %02x %*02x %*02x %63s\n",
362                  rawaddrstr, &prefixlen, ifname) == 3) {
363        // Is this the interface we're looking for?
364        if (strcmp(name, ifname)) {
365            continue;
366        }
367
368        // Put the colons back into the address.
369        for (i = 0, j = 0; i < 32; i++, j++) {
370            addrstr[j] = rawaddrstr[i];
371            if (i % 4 == 3) {
372                addrstr[++j] = ':';
373            }
374        }
375        addrstr[j - 1] = '\0';
376
377        // Don't delete the link-local address as well, or it will disable IPv6
378        // on the interface.
379        if (strncmp(addrstr, "fe80:", 5) == 0) {
380            continue;
381        }
382
383        ret = ifc_del_address(ifname, addrstr, prefixlen);
384        if (ret) {
385            ALOGE("Deleting address %s/%d on %s: %s", addrstr, prefixlen, ifname,
386                 strerror(-ret));
387            lasterror = ret;
388        }
389    }
390
391    fclose(f);
392    return lasterror;
393}
394
395/*
396 * Clears IPv4 addresses on the specified interface.
397 */
398void ifc_clear_ipv4_addresses(const char *name) {
399    unsigned count, addr;
400    ifc_init();
401    for (count=0, addr=1;((addr != 0) && (count < 255)); count++) {
402        if (ifc_get_addr(name, &addr) < 0)
403            break;
404        if (addr)
405            ifc_set_addr(name, 0);
406    }
407    ifc_close();
408}
409
410/*
411 * Clears all IP addresses on the specified interface.
412 */
413int ifc_clear_addresses(const char *name) {
414    ifc_clear_ipv4_addresses(name);
415    return ifc_clear_ipv6_addresses(name);
416}
417
418int ifc_set_hwaddr(const char *name, const void *ptr)
419{
420    int r;
421    struct ifreq ifr;
422    ifc_init_ifr(name, &ifr);
423
424    ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER;
425    memcpy(&ifr.ifr_hwaddr.sa_data, ptr, ETH_ALEN);
426    return ioctl(ifc_ctl_sock, SIOCSIFHWADDR, &ifr);
427}
428
429int ifc_set_mask(const char *name, in_addr_t mask)
430{
431    struct ifreq ifr;
432    int ret;
433
434    ifc_init_ifr(name, &ifr);
435    init_sockaddr_in(&ifr.ifr_addr, mask);
436
437    ret = ioctl(ifc_ctl_sock, SIOCSIFNETMASK, &ifr);
438    if (DBG) printerr("ifc_set_mask(%s, xx) = %d", name, ret);
439    return ret;
440}
441
442int ifc_set_prefixLength(const char *name, int prefixLength)
443{
444    struct ifreq ifr;
445    // TODO - support ipv6
446    if (prefixLength > 32 || prefixLength < 0) return -1;
447
448    in_addr_t mask = prefixLengthToIpv4Netmask(prefixLength);
449    ifc_init_ifr(name, &ifr);
450    init_sockaddr_in(&ifr.ifr_addr, mask);
451
452    return ioctl(ifc_ctl_sock, SIOCSIFNETMASK, &ifr);
453}
454
455int ifc_get_addr(const char *name, in_addr_t *addr)
456{
457    struct ifreq ifr;
458    int ret = 0;
459
460    ifc_init_ifr(name, &ifr);
461    if (addr != NULL) {
462        ret = ioctl(ifc_ctl_sock, SIOCGIFADDR, &ifr);
463        if (ret < 0) {
464            *addr = 0;
465        } else {
466            *addr = ((struct sockaddr_in*) &ifr.ifr_addr)->sin_addr.s_addr;
467        }
468    }
469    return ret;
470}
471
472int ifc_get_info(const char *name, in_addr_t *addr, int *prefixLength, unsigned *flags)
473{
474    struct ifreq ifr;
475    ifc_init_ifr(name, &ifr);
476
477    if (addr != NULL) {
478        if(ioctl(ifc_ctl_sock, SIOCGIFADDR, &ifr) < 0) {
479            *addr = 0;
480        } else {
481            *addr = ((struct sockaddr_in*) &ifr.ifr_addr)->sin_addr.s_addr;
482        }
483    }
484
485    if (prefixLength != NULL) {
486        if(ioctl(ifc_ctl_sock, SIOCGIFNETMASK, &ifr) < 0) {
487            *prefixLength = 0;
488        } else {
489            *prefixLength = ipv4NetmaskToPrefixLength((int)
490                    ((struct sockaddr_in*) &ifr.ifr_addr)->sin_addr.s_addr);
491        }
492    }
493
494    if (flags != NULL) {
495        if(ioctl(ifc_ctl_sock, SIOCGIFFLAGS, &ifr) < 0) {
496            *flags = 0;
497        } else {
498            *flags = ifr.ifr_flags;
499        }
500    }
501
502    return 0;
503}
504
505int ifc_act_on_ipv4_route(int action, const char *ifname, struct in_addr dst, int prefix_length,
506      struct in_addr gw)
507{
508    struct rtentry rt;
509    int result;
510    in_addr_t netmask;
511
512    memset(&rt, 0, sizeof(rt));
513
514    rt.rt_dst.sa_family = AF_INET;
515    rt.rt_dev = (void*) ifname;
516
517    netmask = prefixLengthToIpv4Netmask(prefix_length);
518    init_sockaddr_in(&rt.rt_genmask, netmask);
519    init_sockaddr_in(&rt.rt_dst, dst.s_addr);
520    rt.rt_flags = RTF_UP;
521
522    if (prefix_length == 32) {
523        rt.rt_flags |= RTF_HOST;
524    }
525
526    if (gw.s_addr != 0) {
527        rt.rt_flags |= RTF_GATEWAY;
528        init_sockaddr_in(&rt.rt_gateway, gw.s_addr);
529    }
530
531    ifc_init();
532
533    if (ifc_ctl_sock < 0) {
534        return -errno;
535    }
536
537    result = ioctl(ifc_ctl_sock, action, &rt);
538    if (result < 0) {
539        if (errno == EEXIST) {
540            result = 0;
541        } else {
542            result = -errno;
543        }
544    }
545    ifc_close();
546    return result;
547}
548
549/* deprecated - v4 only */
550int ifc_create_default_route(const char *name, in_addr_t gw)
551{
552    struct in_addr in_dst, in_gw;
553
554    in_dst.s_addr = 0;
555    in_gw.s_addr = gw;
556
557    int ret = ifc_act_on_ipv4_route(SIOCADDRT, name, in_dst, 0, in_gw);
558    if (DBG) printerr("ifc_create_default_route(%s, %d) = %d", name, gw, ret);
559    return ret;
560}
561
562/* deprecated v4-only */
563int ifc_add_host_route(const char *name, in_addr_t dst)
564{
565    struct in_addr in_dst, in_gw;
566
567    in_dst.s_addr = dst;
568    in_gw.s_addr = 0;
569
570    return ifc_act_on_ipv4_route(SIOCADDRT, name, in_dst, 32, in_gw);
571}
572
573int ifc_enable(const char *ifname)
574{
575    int result;
576
577    ifc_init();
578    result = ifc_up(ifname);
579    ifc_close();
580    return result;
581}
582
583int ifc_disable(const char *ifname)
584{
585    unsigned addr, count;
586    int result;
587
588    ifc_init();
589    result = ifc_down(ifname);
590
591    ifc_set_addr(ifname, 0);
592    for (count=0, addr=1;((addr != 0) && (count < 255)); count++) {
593       if (ifc_get_addr(ifname, &addr) < 0)
594            break;
595       if (addr)
596          ifc_set_addr(ifname, 0);
597    }
598
599    ifc_close();
600    return result;
601}
602
603int ifc_reset_connections(const char *ifname, const int reset_mask)
604{
605#ifdef HAVE_ANDROID_OS
606    int result, success;
607    in_addr_t myaddr;
608    struct ifreq ifr;
609    struct in6_ifreq ifr6;
610
611    if (reset_mask & RESET_IPV4_ADDRESSES) {
612        /* IPv4. Clear connections on the IP address. */
613        ifc_init();
614        ifc_get_info(ifname, &myaddr, NULL, NULL);
615        ifc_init_ifr(ifname, &ifr);
616        init_sockaddr_in(&ifr.ifr_addr, myaddr);
617        result = ioctl(ifc_ctl_sock, SIOCKILLADDR,  &ifr);
618        ifc_close();
619    } else {
620        result = 0;
621    }
622
623    if (reset_mask & RESET_IPV6_ADDRESSES) {
624        /*
625         * IPv6. On Linux, when an interface goes down it loses all its IPv6
626         * addresses, so we don't know which connections belonged to that interface
627         * So we clear all unused IPv6 connections on the device by specifying an
628         * empty IPv6 address.
629         */
630        ifc_init6();
631        // This implicitly specifies an address of ::, i.e., kill all IPv6 sockets.
632        memset(&ifr6, 0, sizeof(ifr6));
633        success = ioctl(ifc_ctl_sock6, SIOCKILLADDR,  &ifr6);
634        if (result == 0) {
635            result = success;
636        }
637        ifc_close6();
638    }
639
640    return result;
641#else
642    return 0;
643#endif
644}
645
646/*
647 * Remove the routes associated with the named interface.
648 */
649int ifc_remove_host_routes(const char *name)
650{
651    char ifname[64];
652    in_addr_t dest, gway, mask;
653    int flags, refcnt, use, metric, mtu, win, irtt;
654    struct rtentry rt;
655    FILE *fp;
656    struct in_addr addr;
657
658    fp = fopen("/proc/net/route", "r");
659    if (fp == NULL)
660        return -1;
661    /* Skip the header line */
662    if (fscanf(fp, "%*[^\n]\n") < 0) {
663        fclose(fp);
664        return -1;
665    }
666    ifc_init();
667    for (;;) {
668        int nread = fscanf(fp, "%63s%X%X%X%d%d%d%X%d%d%d\n",
669                           ifname, &dest, &gway, &flags, &refcnt, &use, &metric, &mask,
670                           &mtu, &win, &irtt);
671        if (nread != 11) {
672            break;
673        }
674        if ((flags & (RTF_UP|RTF_HOST)) != (RTF_UP|RTF_HOST)
675                || strcmp(ifname, name) != 0) {
676            continue;
677        }
678        memset(&rt, 0, sizeof(rt));
679        rt.rt_dev = (void *)name;
680        init_sockaddr_in(&rt.rt_dst, dest);
681        init_sockaddr_in(&rt.rt_gateway, gway);
682        init_sockaddr_in(&rt.rt_genmask, mask);
683        addr.s_addr = dest;
684        if (ioctl(ifc_ctl_sock, SIOCDELRT, &rt) < 0) {
685            ALOGD("failed to remove route for %s to %s: %s",
686                 ifname, inet_ntoa(addr), strerror(errno));
687        }
688    }
689    fclose(fp);
690    ifc_close();
691    return 0;
692}
693
694/*
695 * Return the address of the default gateway
696 *
697 * TODO: factor out common code from this and remove_host_routes()
698 * so that we only scan /proc/net/route in one place.
699 *
700 * DEPRECATED
701 */
702int ifc_get_default_route(const char *ifname)
703{
704    char name[64];
705    in_addr_t dest, gway, mask;
706    int flags, refcnt, use, metric, mtu, win, irtt;
707    int result;
708    FILE *fp;
709
710    fp = fopen("/proc/net/route", "r");
711    if (fp == NULL)
712        return 0;
713    /* Skip the header line */
714    if (fscanf(fp, "%*[^\n]\n") < 0) {
715        fclose(fp);
716        return 0;
717    }
718    ifc_init();
719    result = 0;
720    for (;;) {
721        int nread = fscanf(fp, "%63s%X%X%X%d%d%d%X%d%d%d\n",
722                           name, &dest, &gway, &flags, &refcnt, &use, &metric, &mask,
723                           &mtu, &win, &irtt);
724        if (nread != 11) {
725            break;
726        }
727        if ((flags & (RTF_UP|RTF_GATEWAY)) == (RTF_UP|RTF_GATEWAY)
728                && dest == 0
729                && strcmp(ifname, name) == 0) {
730            result = gway;
731            break;
732        }
733    }
734    fclose(fp);
735    ifc_close();
736    return result;
737}
738
739/*
740 * Sets the specified gateway as the default route for the named interface.
741 * DEPRECATED
742 */
743int ifc_set_default_route(const char *ifname, in_addr_t gateway)
744{
745    struct in_addr addr;
746    int result;
747
748    ifc_init();
749    addr.s_addr = gateway;
750    if ((result = ifc_create_default_route(ifname, gateway)) < 0) {
751        ALOGD("failed to add %s as default route for %s: %s",
752             inet_ntoa(addr), ifname, strerror(errno));
753    }
754    ifc_close();
755    return result;
756}
757
758/*
759 * Removes the default route for the named interface.
760 */
761int ifc_remove_default_route(const char *ifname)
762{
763    struct rtentry rt;
764    int result;
765
766    ifc_init();
767    memset(&rt, 0, sizeof(rt));
768    rt.rt_dev = (void *)ifname;
769    rt.rt_flags = RTF_UP|RTF_GATEWAY;
770    init_sockaddr_in(&rt.rt_dst, 0);
771    if ((result = ioctl(ifc_ctl_sock, SIOCDELRT, &rt)) < 0) {
772        ALOGD("failed to remove default route for %s: %s", ifname, strerror(errno));
773    }
774    ifc_close();
775    return result;
776}
777
778int
779ifc_configure(const char *ifname,
780        in_addr_t address,
781        uint32_t prefixLength,
782        in_addr_t gateway,
783        in_addr_t dns1,
784        in_addr_t dns2) {
785
786    char dns_prop_name[PROPERTY_KEY_MAX];
787
788    ifc_init();
789
790    if (ifc_up(ifname)) {
791        printerr("failed to turn on interface %s: %s\n", ifname, strerror(errno));
792        ifc_close();
793        return -1;
794    }
795    if (ifc_set_addr(ifname, address)) {
796        printerr("failed to set ipaddr %s: %s\n", ipaddr_to_string(address), strerror(errno));
797        ifc_close();
798        return -1;
799    }
800    if (ifc_set_prefixLength(ifname, prefixLength)) {
801        printerr("failed to set prefixLength %d: %s\n", prefixLength, strerror(errno));
802        ifc_close();
803        return -1;
804    }
805    if (ifc_create_default_route(ifname, gateway)) {
806        printerr("failed to set default route %s: %s\n", ipaddr_to_string(gateway), strerror(errno));
807        ifc_close();
808        return -1;
809    }
810
811    ifc_close();
812
813    snprintf(dns_prop_name, sizeof(dns_prop_name), "net.%s.dns1", ifname);
814    property_set(dns_prop_name, dns1 ? ipaddr_to_string(dns1) : "");
815    snprintf(dns_prop_name, sizeof(dns_prop_name), "net.%s.dns2", ifname);
816    property_set(dns_prop_name, dns2 ? ipaddr_to_string(dns2) : "");
817
818    return 0;
819}
820
821int ifc_act_on_ipv6_route(int action, const char *ifname, struct in6_addr dst, int prefix_length,
822      struct in6_addr gw)
823{
824    struct in6_rtmsg rtmsg;
825    int result;
826    int ifindex;
827
828    memset(&rtmsg, 0, sizeof(rtmsg));
829
830    ifindex = if_nametoindex(ifname);
831    if (ifindex == 0) {
832        printerr("if_nametoindex() failed: interface %s\n", ifname);
833        return -ENXIO;
834    }
835
836    rtmsg.rtmsg_ifindex = ifindex;
837    rtmsg.rtmsg_dst = dst;
838    rtmsg.rtmsg_dst_len = prefix_length;
839    rtmsg.rtmsg_flags = RTF_UP;
840
841    if (prefix_length == 128) {
842        rtmsg.rtmsg_flags |= RTF_HOST;
843    }
844
845    if (memcmp(&gw, &in6addr_any, sizeof(in6addr_any))) {
846        rtmsg.rtmsg_flags |= RTF_GATEWAY;
847        rtmsg.rtmsg_gateway = gw;
848    }
849
850    ifc_init6();
851
852    if (ifc_ctl_sock6 < 0) {
853        return -errno;
854    }
855
856    result = ioctl(ifc_ctl_sock6, action, &rtmsg);
857    if (result < 0) {
858        if (errno == EEXIST) {
859            result = 0;
860        } else {
861            result = -errno;
862        }
863    }
864    ifc_close6();
865    return result;
866}
867
868int ifc_act_on_route(int action, const char *ifname, const char *dst, int prefix_length,
869        const char *gw)
870{
871    int ret = 0;
872    struct sockaddr_in ipv4_dst, ipv4_gw;
873    struct sockaddr_in6 ipv6_dst, ipv6_gw;
874    struct addrinfo hints, *addr_ai, *gw_ai;
875
876    memset(&hints, 0, sizeof(hints));
877    hints.ai_family = AF_UNSPEC;  /* Allow IPv4 or IPv6 */
878    hints.ai_flags = AI_NUMERICHOST;
879
880    ret = getaddrinfo(dst, NULL, &hints, &addr_ai);
881
882    if (ret != 0) {
883        printerr("getaddrinfo failed: invalid address %s\n", dst);
884        return -EINVAL;
885    }
886
887    if (gw == NULL || (strlen(gw) == 0)) {
888        if (addr_ai->ai_family == AF_INET6) {
889            gw = "::";
890        } else if (addr_ai->ai_family == AF_INET) {
891            gw = "0.0.0.0";
892        }
893    }
894
895    if (((addr_ai->ai_family == AF_INET6) && (prefix_length < 0 || prefix_length > 128)) ||
896            ((addr_ai->ai_family == AF_INET) && (prefix_length < 0 || prefix_length > 32))) {
897        printerr("ifc_add_route: invalid prefix length");
898        freeaddrinfo(addr_ai);
899        return -EINVAL;
900    }
901
902    ret = getaddrinfo(gw, NULL, &hints, &gw_ai);
903    if (ret != 0) {
904        printerr("getaddrinfo failed: invalid gateway %s\n", gw);
905        freeaddrinfo(addr_ai);
906        return -EINVAL;
907    }
908
909    if (addr_ai->ai_family != gw_ai->ai_family) {
910        printerr("ifc_add_route: different address families: %s and %s\n", dst, gw);
911        freeaddrinfo(addr_ai);
912        freeaddrinfo(gw_ai);
913        return -EINVAL;
914    }
915
916    if (addr_ai->ai_family == AF_INET6) {
917        memcpy(&ipv6_dst, addr_ai->ai_addr, sizeof(struct sockaddr_in6));
918        memcpy(&ipv6_gw, gw_ai->ai_addr, sizeof(struct sockaddr_in6));
919        ret = ifc_act_on_ipv6_route(action, ifname, ipv6_dst.sin6_addr,
920                prefix_length, ipv6_gw.sin6_addr);
921    } else if (addr_ai->ai_family == AF_INET) {
922        memcpy(&ipv4_dst, addr_ai->ai_addr, sizeof(struct sockaddr_in));
923        memcpy(&ipv4_gw, gw_ai->ai_addr, sizeof(struct sockaddr_in));
924        ret = ifc_act_on_ipv4_route(action, ifname, ipv4_dst.sin_addr,
925                prefix_length, ipv4_gw.sin_addr);
926    } else {
927        printerr("ifc_add_route: getaddrinfo returned un supported address family %d\n",
928                  addr_ai->ai_family);
929        ret = -EAFNOSUPPORT;
930    }
931
932    freeaddrinfo(addr_ai);
933    freeaddrinfo(gw_ai);
934    return ret;
935}
936
937/*
938 * DEPRECATED
939 */
940int ifc_add_ipv4_route(const char *ifname, struct in_addr dst, int prefix_length,
941      struct in_addr gw)
942{
943    int i =ifc_act_on_ipv4_route(SIOCADDRT, ifname, dst, prefix_length, gw);
944    if (DBG) printerr("ifc_add_ipv4_route(%s, xx, %d, xx) = %d", ifname, prefix_length, i);
945    return i;
946}
947
948/*
949 * DEPRECATED
950 */
951int ifc_add_ipv6_route(const char *ifname, struct in6_addr dst, int prefix_length,
952      struct in6_addr gw)
953{
954    return ifc_act_on_ipv6_route(SIOCADDRT, ifname, dst, prefix_length, gw);
955}
956
957int ifc_add_route(const char *ifname, const char *dst, int prefix_length, const char *gw)
958{
959    int i = ifc_act_on_route(SIOCADDRT, ifname, dst, prefix_length, gw);
960    if (DBG) printerr("ifc_add_route(%s, %s, %d, %s) = %d", ifname, dst, prefix_length, gw, i);
961    return i;
962}
963
964int ifc_remove_route(const char *ifname, const char*dst, int prefix_length, const char *gw)
965{
966    return ifc_act_on_route(SIOCDELRT, ifname, dst, prefix_length, gw);
967}
968