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Commit 47ddb515 authored by Lorenzo Colitti's avatar Lorenzo Colitti
Browse files

Support adding, deleting, and clearing IPv6 addrs. 

- Provide a function to add and delete IPv4/IPv6 addresses
  using netlink.
- Provide a function that clears all IP addresses on an
  interface that can be used by netd.

Also, a couple of cleanups:

- Update the header file to match reality, and include the
  header file in the implementation. Also fix a caller that
  has an incorrect method signature.
- Fix whitespace in Android.mk.

Change-Id: Ifba9d60cdfffb0b7e5c3b9c6ab328f5f77d259c4
parent b14bbf02

include/netutils/ifc.h

+10 −5
Original line number Diff line number Diff line
@@ -38,9 +38,13 @@ extern int ifc_reset_connections(const char *ifname, const int reset_mask); 


extern int ifc_get_addr(const char *name, in_addr_t *addr);

extern int ifc_set_addr(const char *name, in_addr_t addr);

extern int ifc_get_prefixLength(const char *name, uint32_t *prefixLength);

extern int ifc_set_prefixLength(const char *name, uint32_t prefixLength);

extern int ifc_add_address(const char *name, const char *address,

                           int prefixlen);

extern int ifc_del_address(const char *name, const char *address,

                           int prefixlen);

extern int ifc_set_prefixLength(const char *name, int prefixLength);

extern int ifc_set_hwaddr(const char *name, const void *ptr);

extern int ifc_clear_addresses(const char *name);



/* This function is deprecated. Use ifc_add_route instead. */

extern int ifc_add_host_route(const char *name, in_addr_t addr);
@@ -53,9 +57,10 @@ extern int ifc_create_default_route(const char *name, in_addr_t addr); 
extern int ifc_remove_default_route(const char *ifname);

extern int ifc_add_route(const char *name, const char *addr, int prefix_length,

                         const char *gw);



extern int ifc_get_info(const char *name, in_addr_t *addr, in_addr_t *mask,

                        in_addr_t *flags);

extern int ifc_remove_route(const char *ifname, const char *dst,

                            int prefix_length, const char *gw);

extern int ifc_get_info(const char *name, in_addr_t *addr, int *prefixLength,

                        unsigned *flags);



extern int ifc_configure(const char *ifname, in_addr_t address,

                         uint32_t prefixLength, in_addr_t gateway,

libnetutils/ifc_utils.c

+209 −3
Original line number Diff line number Diff line
@@ -26,15 +26,18 @@ 
#include <netinet/in.h>

#include <arpa/inet.h>

#include <net/if.h>

#include <netdb.h>



#include <linux/if.h>

#include <linux/if_ether.h>

#include <linux/if_arp.h>

#include <linux/sockios.h>

#include <linux/netlink.h>

#include <linux/route.h>

#include <linux/ipv6_route.h>

#include <netdb.h>

#include <linux/wireless.h>

#include <linux/rtnetlink.h>

#include <linux/sockios.h>



#include "netutils/ifc.h"



#ifdef ANDROID

#define LOG_TAG "NetUtils"
@@ -52,6 +55,8 @@ static int ifc_ctl_sock6 = -1; 
void printerr(char *fmt, ...);



#define DBG 0

#define INET_ADDRLEN 4

#define INET6_ADDRLEN 16



in_addr_t prefixLengthToIpv4Netmask(int prefix_length)

{
@@ -88,6 +93,28 @@ static const char *ipaddr_to_string(in_addr_t addr) 
    return inet_ntoa(in_addr);

}



int string_to_ip(const char *string, struct sockaddr_storage *ss) {

    struct addrinfo hints, *ai;

    int ret;



    if (ss == NULL) {

        return -EFAULT;

    }



    memset(&hints, 0, sizeof(hints));

    hints.ai_family = AF_UNSPEC;

    hints.ai_flags = AI_NUMERICHOST;

    hints.ai_socktype = SOCK_DGRAM;



    ret = getaddrinfo(string, NULL, &hints, &ai);

    if (ret == 0) {

        memcpy(ss, ai->ai_addr, ai->ai_addrlen);

        freeaddrinfo(ai);

    }



    return ret;

}



int ifc_init(void)

{

    int ret;
@@ -209,6 +236,185 @@ int ifc_set_addr(const char *name, in_addr_t addr) 
    return ret;

}



/*

 * Adds or deletes an IP address on an interface.

 *

 * Action is one of:

 * - RTM_NEWADDR (to add a new address)

 * - RTM_DELADDR (to delete an existing address)

 *

 * Returns zero on success and negative errno on failure.

 */

int ifc_act_on_address(int action, const char *name, const char *address,

                       int prefixlen) {

    int ifindex, s, len, ret;

    struct sockaddr_storage ss;

    void *addr;

    size_t addrlen;

    struct {

        struct nlmsghdr n;

        struct ifaddrmsg r;

        // Allow for IPv6 address, headers, and padding.

        char attrbuf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +

                     NLMSG_ALIGN(sizeof(struct rtattr)) +

                     NLMSG_ALIGN(INET6_ADDRLEN)];

    } req;

    struct rtattr *rta;

    struct nlmsghdr *nh;

    struct nlmsgerr *err;

    char buf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +

             NLMSG_ALIGN(sizeof(struct nlmsgerr)) +

             NLMSG_ALIGN(sizeof(struct nlmsghdr))];



    // Get interface ID.

    ifindex = if_nametoindex(name);

    if (ifindex == 0) {

        return -errno;

    }



    // Convert string representation to sockaddr_storage.

    ret = string_to_ip(address, &ss);

    if (ret) {

        return ret;

    }



    // Determine address type and length.

    if (ss.ss_family == AF_INET) {

        struct sockaddr_in *sin = (struct sockaddr_in *) &ss;

        addr = &sin->sin_addr;

        addrlen = INET_ADDRLEN;

    } else if (ss.ss_family == AF_INET6) {

        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) &ss;

        addr = &sin6->sin6_addr;

        addrlen = INET6_ADDRLEN;

    } else {

        return -EAFNOSUPPORT;

    }



    // Fill in netlink structures.

    memset(&req, 0, sizeof(req));



    // Netlink message header.

    req.n.nlmsg_len = NLMSG_LENGTH(sizeof(req.r));

    req.n.nlmsg_type = action;

    req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;

    req.n.nlmsg_pid = getpid();



    // Interface address message header.

    req.r.ifa_family = ss.ss_family;

    req.r.ifa_prefixlen = prefixlen;

    req.r.ifa_index = ifindex;



    // Routing attribute. Contains the actual IP address.

    rta = (struct rtattr *) (((char *) &req) + NLMSG_ALIGN(req.n.nlmsg_len));

    rta->rta_type = IFA_LOCAL;

    rta->rta_len = RTA_LENGTH(addrlen);

    req.n.nlmsg_len = NLMSG_ALIGN(req.n.nlmsg_len) + RTA_LENGTH(addrlen);

    memcpy(RTA_DATA(rta), addr, addrlen);



    s = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);

    if (send(s, &req, req.n.nlmsg_len, 0) < 0) {

        close(s);

        return -errno;

    }



    len = recv(s, buf, sizeof(buf), 0);

    close(s);

    if (len < 0) {

        return -errno;

    }



    // Parse the acknowledgement to find the return code.

    nh = (struct nlmsghdr *) buf;

    if (!NLMSG_OK(nh, (unsigned) len) || nh->nlmsg_type != NLMSG_ERROR) {

        return -EINVAL;

    }

    err = NLMSG_DATA(nh);



    // Return code is negative errno.

    return err->error;

}



int ifc_add_address(const char *name, const char *address, int prefixlen) {

    return ifc_act_on_address(RTM_NEWADDR, name, address, prefixlen);

}



int ifc_del_address(const char *name, const char * address, int prefixlen) {

    return ifc_act_on_address(RTM_DELADDR, name, address, prefixlen);

}



/*

 * Clears IPv6 addresses on the specified interface.

 */

int ifc_clear_ipv6_addresses(const char *name) {

    char rawaddrstr[INET6_ADDRSTRLEN], addrstr[INET6_ADDRSTRLEN];

    unsigned int prefixlen;

    int lasterror = 0, i, j, ret;

    char ifname[64];  // Currently, IFNAMSIZ = 16.

    FILE *f = fopen("/proc/net/if_inet6", "r");

    if (!f) {

        return -errno;

    }



    // Format:

    // 20010db8000a0001fc446aa4b5b347ed 03 40 00 01    wlan0

    while (fscanf(f, "%32s %*02x %02x %*02x %*02x %63s\n",

                  rawaddrstr, &prefixlen, ifname) == 3) {

        // Is this the interface we're looking for?

        if (strcmp(name, ifname)) {

            continue;

        }



        // Put the colons back into the address.

        for (i = 0, j = 0; i < 32; i++, j++) {

            addrstr[j] = rawaddrstr[i];

            if (i % 4 == 3) {

                addrstr[++j] = ':';

            }

        }

        addrstr[j - 1] = '\0';



        // Don't delete the link-local address as well, or it will disable IPv6

        // on the interface.

        if (strncmp(addrstr, "fe80:", 5) == 0) {

            continue;

        }



        ret = ifc_del_address(ifname, addrstr, prefixlen);

        if (ret) {

            LOGE("Deleting address %s/%d on %s: %s", addrstr, prefixlen, ifname,

                 strerror(-ret));

            lasterror = ret;

        }

    }



    fclose(f);

    return lasterror;

}



/*

 * Clears IPv4 addresses on the specified interface.

 */

void ifc_clear_ipv4_addresses(const char *name) {

    unsigned count, addr;

    ifc_init();

    for (count=0, addr=1;((addr != 0) && (count < 255)); count++) {

        if (ifc_get_addr(name, &addr) < 0)

            break;

        if (addr)

            ifc_set_addr(name, 0);

    }

    ifc_close();

}



/*

 * Clears all IP addresses on the specified interface.

 */

int ifc_clear_addresses(const char *name) {

    ifc_clear_ipv4_addresses(name);

    return ifc_clear_ipv6_addresses(name);

}



int ifc_set_hwaddr(const char *name, const void *ptr)

{

    int r;

netcfg/netcfg.c

+2 −1
Original line number Diff line number Diff line
@@ -50,8 +50,9 @@ void usage(void) 


int dump_interface(const char *name)

{

    unsigned addr, prefixLength, flags;

    unsigned addr, flags;

    unsigned char hwbuf[ETH_ALEN];

    int prefixLength;



    if(ifc_get_info(name, &addr, &prefixLength, &flags)) {

        return 0;

libnetutils/Android.mk

+2 −2

File changed.

Contains only whitespace changes.