Logo Search packages:      
Sourcecode: heartbeat version File versions

IPv6addr.c

/*
 * This program manages IPv6 address.
 *
 * Author: Huang Zhen <zhenh@cn.ibm.com>
 * Copyright (c) 2004 International Business Machines
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */
 
/*
 * It can add an IPv6 address, or remove one.
 *
 * Usage:  IPv6addr ipv6-address {start|stop|status|monitor}
 *
 * The "start" arg adds an IPv6 address.
 * The "stop" arg removes one.
 * The "status" arg shows whether the IPv6 address exists
 * The "monitor" arg shows whether the IPv6 address can be pinged (ICMPv6 ECHO)
 */
 
/*
 * ipv6-address:
 *
 * currently the following forms are legal:
 *    address
 *    address/prefix
 *
 *     E.g.
 *    3ffe:ffff:0:f101::1
 *    3ffe:ffff:0:f101::1/64
 *
 */
 
/*
 * start:
 *    1.IPv6addr will choice a proper interface for the new address.
 *    2.Then assign the new address to the interface.
 *    3.Wait until the new address is available (reply ICMPv6 ECHO packet)
 *    4.Send out the unsolicited advertisements.
 *
 *    return 0(LSB_EXIT_OK) for success
 *    return 1(LSB_EXIT_GENERIC) for failure
 *
 *
 * stop:
 *    remove the address from the inferface.
 *
 *    return 0(LSB_EXIT_OK) for success
 *    return 1(LSB_EXIT_GENERIC) for failure
 *
 * status:
 *    return the status of the address. only check whether it exists.
 *
 *    return 0(LSB_STATUS_OK) for existing
 *    return 1(LSB_STATUS_STOPPED) for not existing
 *
 *
 * monitor:
 *    ping the address by ICMPv6 ECHO request.
 *
 *    return 0(LSB_STATUS_OK) for response correctly.
 *    return 1(LSB_STATUS_STOPPED) for no response.
 *
 */
 
#include <asm/types.h>
#include <libgen.h>
#include <syslog.h>
#include <clplumbing/cl_log.h>
#include <libnet.h>
#include <linux/icmpv6.h>
#include <clplumbing/lsb_exitcodes.h>



#define PIDDIR "/var/run/"
#define PIDFILE_BASE PIDDIR "/IPv6addr-"



const char* IF_INET6          = "/proc/net/if_inet6";
const char* APP_NAME          = "IPv6addr";

const char* START_CMD   = "start";
const char* STOP_CMD    = "stop";
const char* STATUS_CMD  = "status";
const char* MONITOR_CMD       = "monitor";
const char* ADVT_CMD    = "advt";
char        BCAST_ADDR[]      = "ff02::1";
const int   UA_REPEAT_COUNT   = 5;
const int   QUERY_COUNT = 5;

struct in6_ifreq {
    struct in6_addr ifr6_addr;
    __u32 ifr6_prefixlen;
    unsigned int ifr6_ifindex;
};

static int start_addr6(struct in6_addr* addr6, int prefix_len);
static int stop_addr6(struct in6_addr* addr6, int prefix_len);
static int status_addr6(struct in6_addr* addr6, int prefix_len);
static int monitor_addr6(struct in6_addr* addr6, int prefix_len);
static int advt_addr6(struct in6_addr* addr6, int prefix_len);


static void usage(const char* self);
int write_pid_file(const char *pid_file);
int create_pid_directory(const char *pid_file);
static void byebye(int nsig);

static char* find_if(struct in6_addr* addr_target, int* plen_target);
static char* get_if(struct in6_addr* addr_target, int* plen_target);
static int assign_addr6(struct in6_addr* addr6, int prefix_len, char* if_name);
static int unassign_addr6(struct in6_addr* addr6, int prefix_len, char* if_name);
int is_addr6_available(struct in6_addr* addr6);
static int send_ua(struct in6_addr* src_ip, char* if_name);

int
main(int argc, char* argv[])
{
      char        pid_file[256];
      int         ret;
      char*       cp;
      int         prefix_len;
      struct in6_addr   addr6;

      /* Check the count of parameters first */
      if (argc < 3) {
            usage(argv[0]);
            return EXIT_FAILURE;
      }

      /* set termination signal */
      siginterrupt(SIGTERM, 1);
      signal(SIGTERM, byebye);

      /* open system log */
      openlog(APP_NAME, LOG_CONS | LOG_PID, LOG_USER);

      /* check the first parameter, should be a IPv6 address */
      if ((cp = strchr(argv[1], '/'))) {
            prefix_len = atol(cp + 1);
            if ((prefix_len < 0) || (prefix_len > 128)) {
                  usage(argv[0]);
                  return EXIT_FAILURE;
            } 
            *cp=0;
      } else {
            prefix_len = 0;
      }
      
      if (inet_pton(AF_INET6, argv[1], &addr6) <= 0) {
            usage(argv[0]);
            return EXIT_FAILURE;
      }
      
      /* Check whether this system supports IPv6 */
      if (access(IF_INET6, R_OK)) {
            cl_log(LOG_ERR, "No support for INET6 on this system.");
            return EXIT_FAILURE;
      }
      
      /* create the pid file so we can make sure that only one IPv6addr
       * for this address is running
       */
      if (snprintf(pid_file, sizeof(pid_file), "%s%s", PIDFILE_BASE, argv[1])
            >= (int)sizeof(pid_file)) {
            cl_log(LOG_ERR, "Pid file truncated");
            return EXIT_FAILURE;
      }

      if (write_pid_file(pid_file) < 0) {
            return EXIT_FAILURE;
      }


      /* switch the command */
      if (0 == strncmp(START_CMD,argv[2], strlen(START_CMD))) {
            ret = start_addr6(&addr6, prefix_len);
      }else if (0 == strncmp(STOP_CMD,argv[2], strlen(STOP_CMD))) {
            ret = stop_addr6(&addr6, prefix_len);
      }else if (0 == strncmp(STATUS_CMD,argv[2], strlen(STATUS_CMD))) {
            ret = status_addr6(&addr6, prefix_len);
      }else if (0 ==strncmp(MONITOR_CMD,argv[2], strlen(MONITOR_CMD))) {
            ret = monitor_addr6(&addr6, prefix_len);
      }else if (0 ==strncmp(ADVT_CMD,argv[2], strlen(MONITOR_CMD))) {
            ret = advt_addr6(&addr6, prefix_len);
      }else{
            usage(argv[0]);
            ret = EXIT_FAILURE;
      }
      
      /* release the pid file */
      unlink(pid_file);

      return ret;
}
int
start_addr6(struct in6_addr* addr6, int prefix_len)
{
      /* First, we need to find a proper device to assign the address */
      int   i;
      char* if_name = find_if(addr6, &prefix_len);
      if (NULL == if_name) {
            cl_log(LOG_ERR, "no valid mecahnisms");
            return LSB_EXIT_GENERIC;
      }

      /* Assign the address */
      if (0 != assign_addr6(addr6, prefix_len, if_name)) {
            cl_log(LOG_ERR, "failed to assign the address to %s", if_name);
            return LSB_EXIT_GENERIC;
      }

      /* Check whether the address available */
      for (i = 0; i < QUERY_COUNT; i++) {
            if (0 == is_addr6_available(addr6)) {
                  break;
            }
            sleep(1);
      }
      if (i == QUERY_COUNT) {
            cl_log(LOG_ERR, "failed to ping the address");
            return LSB_EXIT_GENERIC;
      }
      
      /* Send unsolicited advertisement packet to neighbor */
      for (i = 0; i < UA_REPEAT_COUNT; i++) {
            send_ua(addr6, if_name);
            sleep(1);
      }
      return LSB_EXIT_OK;
}

int
advt_addr6(struct in6_addr* addr6, int prefix_len)
{
      /* First, we need to find a proper device to assign the address */
      char* if_name = get_if(addr6, &prefix_len);
      int   i;
      if (NULL == if_name) {
            cl_log(LOG_ERR, "no valid mecahnisms");
            return LSB_EXIT_GENERIC;
      }
      /* Send unsolicited advertisement packet to neighbor */
      for (i = 0; i < UA_REPEAT_COUNT; i++) {
            send_ua(addr6, if_name);
            sleep(1);
      }
      return LSB_STATUS_OK;
}
      
int
stop_addr6(struct in6_addr* addr6, int prefix_len)
{
      char* if_name = get_if(addr6, &prefix_len);

      if (NULL == if_name) {
            cl_log(LOG_ERR, "no valid mechanisms.");
            /* I think this should be a success exit according to LSB. */
            return LSB_EXIT_GENERIC;
      }

      /* Unassign the address */
      if (0 != unassign_addr6(addr6, prefix_len, if_name)) {
            cl_log(LOG_ERR, "failed to assign the address to %s", if_name);
            return LSB_EXIT_GENERIC;
      }

      return LSB_EXIT_OK;
}

int
status_addr6(struct in6_addr* addr6, int prefix_len)
{
      char* if_name = get_if(addr6, &prefix_len);
      if (NULL == if_name) {
            return LSB_STATUS_STOPPED;
      }
      return LSB_STATUS_OK;
}
      
int
monitor_addr6(struct in6_addr* addr6, int prefix_len)
{
      if(0 == is_addr6_available(addr6)) {
            return LSB_STATUS_OK;
      }
      return LSB_STATUS_STOPPED;

}

/* Send an unsolicited advertisement packet
 * Please refer to rfc2461
 */
int
send_ua(struct in6_addr* src_ip, char* if_name)
{
      libnet_t *l;
      char errbuf[LIBNET_ERRBUF_SIZE];

      struct libnet_in6_addr dst_ip;
      struct libnet_ether_addr *mac_address;
      char payload[24];


      if ((l=libnet_init(LIBNET_RAW6, if_name, errbuf)) == NULL) {
            cl_log(LOG_ERR, "libnet_init failure on %s", if_name);
            return -1;
      }

      mac_address = libnet_get_hwaddr(l);
      if (!mac_address) {
            cl_log(LOG_ERR, "libnet_get_hwaddr: %s", errbuf);
            return -1;
      }

      dst_ip = libnet_name2addr6(l, BCAST_ADDR, LIBNET_DONT_RESOLVE);

      memcpy(payload,src_ip->s6_addr,16);
      payload[16] = 2; /* 2 for Target Link-layer Address */
      payload[17] = 1; /* The length of the option */
      memcpy(payload+18,mac_address->ether_addr_octet, 6);

      libnet_seed_prand(l);
      /* 0x2000: RSO */
      libnet_build_icmpv4_echo(136,0,0,0x2000,0,payload,sizeof(payload),
                         l,LIBNET_PTAG_INITIALIZER);
      libnet_build_ipv6(0,0,LIBNET_ICMPV6_H + sizeof(payload),IPPROTO_ICMP6,
                        255,*(struct libnet_in6_addr*)src_ip,
                        dst_ip,NULL,0,l,0);

        if (libnet_write(l) == -1)
        {
            cl_log(LOG_ERR, "libnet_write: %s", libnet_geterror(l));
            return -1;
      }

      return 0;
}

/* find a proper network interface to assign the address */
char*
find_if(struct in6_addr* addr_target, int* plen_target)
{
      FILE *f;
      char addr6[40];
      static char devname[20]="";
      struct in6_addr addr;
      struct in6_addr mask;
      int         plen;
      int         scope;
      int         dad_status;
      int         if_idx;
      char addr6p[8][5];

      /* open /proc/net/if_inet6 file */
      if ((f = fopen(IF_INET6, "r")) == NULL) {
            return NULL;
      }

      /* Loop for each entry */
      while ( fscanf(f,"%4s%4s%4s%4s%4s%4s%4s%4s %02x %02x %02x %02x %20s\n",
                  addr6p[0], addr6p[1], addr6p[2], addr6p[3],
                  addr6p[4], addr6p[5], addr6p[6], addr6p[7],
                  &if_idx, &plen, &scope, &dad_status, devname) != EOF){

            int         i;
            int         n;
            int         s;
            gboolean    same = TRUE;

            sprintf(addr6, "%s:%s:%s:%s:%s:%s:%s:%s",
                  addr6p[0], addr6p[1], addr6p[2], addr6p[3],
                  addr6p[4], addr6p[5], addr6p[6], addr6p[7]);
      
            /* Only Global address entry would be considered.
             * maybe change?
             */
            if (0 != scope) {
                  continue;
            }

            /* If specified prefix, only same prefix entry
             * would be considered.
             */
            if (*plen_target!=0 && plen != *plen_target) {
                  continue;
            }
            *plen_target = plen;
            
            /* Convert string to sockaddr_in6 */
            inet_pton(AF_INET6, addr6, &addr);

            /* Make the mask based on prefix length */
            for (i = 0; i < 16; i++) {
                  mask.s6_addr[i] = 0;
            }     
            n = plen / 8;
            for (i = 0; i < n+1; i++) {
                  mask.s6_addr[i] = 0xFF;
            }
            s = 8 - plen % 8;
            mask.s6_addr[n]<<=s;

            /* compare addr and addr_target */
            same = TRUE;
            for (i = 0; i < 16; i++) {
                  if ((addr.s6_addr[i]&mask.s6_addr[i]) !=
                      (addr_target->s6_addr[i]&mask.s6_addr[i])) {
                        same = FALSE;
                        break;
                  }
            }
            
            /* We found it!   */
            if (same) {
                  fclose(f);
                  return devname;
            }
      }
      fclose(f);
      return NULL;
}
/* get the device name and the plen_target of a special address */
char*
get_if(struct in6_addr* addr_target, int* plen_target)
{
      FILE *f;
      char addr6[40];
      static char devname[20]="";
      struct in6_addr addr;
      int plen, scope, dad_status, if_idx;
      char addr6p[8][5];

      /* open /proc/net/if_inet6 file */
      if ((f = fopen(IF_INET6, "r")) == NULL) {
            return NULL;
      }
      /* loop for each entry */
      while ( fscanf(f,"%4s%4s%4s%4s%4s%4s%4s%4s %02x %02x %02x %02x %20s\n",
            addr6p[0], addr6p[1], addr6p[2], addr6p[3],
            addr6p[4], addr6p[5], addr6p[6], addr6p[7],
            &if_idx, &plen, &scope, &dad_status, devname) != EOF) {

            sprintf(addr6, "%s:%s:%s:%s:%s:%s:%s:%s",
                  addr6p[0], addr6p[1], addr6p[2], addr6p[3],
                  addr6p[4], addr6p[5], addr6p[6], addr6p[7]);

            /* Only Global address entry would be considered.
             * maybe change
             */
            if (0 != scope) {
                  continue;
            }

            /* "if" specified prefix, only same prefix entry
             * would be considered.
             */
            if (*plen_target!=0 && plen != *plen_target) {
                  continue;
            }
            *plen_target = plen;

            /* Convert to sockaddr_in6 */
            inet_pton(AF_INET6, addr6, &addr);

            /* We found it! */
            if (0 == memcmp(&addr, addr_target,sizeof(addr))) {
                  fclose(f);
                  return devname;
            }
      }
      fclose(f);
      return NULL;
}
int
assign_addr6(struct in6_addr* addr6, int prefix_len, char* if_name)
{
      struct in6_ifreq ifr6;

      /* Get socket first */
      int         fd;
      struct ifreq      ifr;

      fd = socket(AF_INET6, SOCK_DGRAM, 0);
      if (fd < 0) {
            return 1;
      }

      /* Query the index of the if */
      strcpy(ifr.ifr_name, if_name);
      if (ioctl(fd, SIOGIFINDEX, &ifr) < 0) {
            return -1;
      }

      /* Assign the address to the if */
      ifr6.ifr6_addr = *addr6;
      ifr6.ifr6_ifindex = ifr.ifr_ifindex;
      ifr6.ifr6_prefixlen = prefix_len;
      if (ioctl(fd, SIOCSIFADDR, &ifr6) < 0) {
            return -1;
      }
      close (fd);
      return 0;
}
int
unassign_addr6(struct in6_addr* addr6, int prefix_len, char* if_name)
{
      int               fd;
      struct ifreq            ifr;
      struct in6_ifreq  ifr6;

      /* Get socket first */
      fd = socket(AF_INET6, SOCK_DGRAM, 0);
      if (fd < 0) {
            return 1;
      }

      /* Query the index of the if */
      strcpy(ifr.ifr_name, if_name);
      if (ioctl(fd, SIOGIFINDEX, &ifr) < 0) {
            return -1;
      }

      /* Unassign the address to the if */
      ifr6.ifr6_addr = *addr6;
      ifr6.ifr6_ifindex = ifr.ifr_ifindex;
      ifr6.ifr6_prefixlen = prefix_len;
      if (ioctl(fd, SIOCDIFADDR, &ifr6) < 0) {
            return -1;
      }
      
      close (fd);
      return 0;
}
int
is_addr6_available(struct in6_addr* addr6)
{
      struct sockaddr_in6     addr;
      struct icmp6hdr         icmph;
      u_char                  outpack[64];
      int               icmp_sock;
      int               ret;
      struct iovec            iov;
      u_char                  packet[64];
      struct msghdr           msg;
      struct in6_addr         local;

      icmp_sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
      icmph.icmp6_type = ICMPV6_ECHO_REQUEST;
      icmph.icmp6_code = 0;
      icmph.icmp6_cksum = 0;
      icmph.icmp6_sequence = htons(0);
      icmph.icmp6_identifier = 0;

      memcpy(&outpack, &icmph, sizeof(icmph));

      memset(&addr, 0, sizeof(struct sockaddr_in6));
      addr.sin6_family = AF_INET6;
      addr.sin6_port = htons(IPPROTO_ICMPV6);
      memcpy(&addr.sin6_addr,addr6,sizeof(struct in6_addr));

      ret = sendto(icmp_sock, (char *)outpack, 64, 0,
                     (struct sockaddr *) &addr,
                     sizeof(struct sockaddr_in6));
      if (0 >= ret) {
            return -1;
      }

      iov.iov_base = (char *)packet;
      iov.iov_len = 64; /* This should be a system #define */

      msg.msg_name = &addr;
      msg.msg_namelen = sizeof(addr);
      msg.msg_iov = &iov;
      msg.msg_iovlen = 1;
      msg.msg_control = NULL;
      msg.msg_controllen = 0;

      ret = recvmsg(icmp_sock, &msg, MSG_DONTWAIT);
      if (0 >= ret) {
            return -1;
      }
      inet_pton(AF_INET6, "::1", &local);
      if (0 != memcmp(&local, &addr.sin6_addr,sizeof(local))) {
            return -1;
      }
      
      return 0;
}

static void usage(const char* self)
{
      printf("usage: %s ip-address {start|stop|status|monitor}\n",self);
      return;
}

/* Following code is copied from send_arp.c, linux-HA project. */
void
byebye(int nsig)
{
      (void)nsig;
      /* Avoid an "error exit" log message if we're killed */
      exit(0);
}

int
create_pid_directory(const char *pid_file)
{
      int status;
      struct stat stat_buf;
      char* dir;

      dir = strdup(pid_file);
      if (!dir) {
            cl_log(LOG_INFO, "Memory allocation failure: %s\n",
                        strerror(errno));
            return -1;
      }

      dirname(dir);

      status = stat(dir, &stat_buf);

      if (status < 0 && errno != ENOENT && errno != ENOTDIR) {
            cl_log(LOG_INFO, "Could not stat pid-file directory "
                        "[%s]: %s", dir, strerror(errno));
            free(dir);
            return -1;
      }

      if (!status) {
            if (S_ISDIR(stat_buf.st_mode)) {
                  return 0;
            }
            cl_log(LOG_INFO, "Pid-File directory exists but is "
                        "not a directory [%s]", dir);
            free(dir);
            return -1;
        }

      if (mkdir(dir, S_IRUSR|S_IWUSR|S_IXUSR | S_IRGRP|S_IXGRP) < 0) {
            cl_log(LOG_INFO, "Could not create pid-file directory "
                        "[%s]: %s", dir, strerror(errno));
            free(dir);
            return -1;
      }

      return 0;
}

int
write_pid_file(const char *pid_file)
{

      int         pidfilefd;
      char        pidbuf[11];
      unsigned long   pid;
      ssize_t     bytes;

      if (*pid_file != '/') {
            cl_log(LOG_INFO, "Invalid pid-file name, must begin with a "
                        "'/' [%s]\n", pid_file);
            return -1;
      }

      if (create_pid_directory(pid_file) < 0) {
            return -1;
      }

      while (1) {
            pidfilefd = open(pid_file, O_CREAT|O_EXCL|O_RDWR,
                        S_IRUSR|S_IWUSR);
            if (pidfilefd < 0) {
                  if (errno != EEXIST) { /* Old PID file */
                        cl_log(LOG_INFO, "Could not open pid-file "
                                    "[%s]: %s", pid_file,
                                    strerror(errno));
                        return -1;
                  }
            }
            else {
                  break;
            }

            pidfilefd = open(pid_file, O_RDONLY, S_IRUSR|S_IWUSR);
            if (pidfilefd < 0) {
                  cl_log(LOG_INFO, "Could not open pid-file "
                              "[%s]: %s", pid_file,
                              strerror(errno));
                  return -1;
            }

            while (1) {
                  bytes = read(pidfilefd, pidbuf, sizeof(pidbuf)-1);
                  if (bytes < 0) {
                        if (errno == EINTR) {
                              continue;
                        }
                        cl_log(LOG_INFO, "Could not read pid-file "
                                    "[%s]: %s", pid_file,
                                    strerror(errno));
                        return -1;
                  }
                  pidbuf[bytes] = '\0';
                  break;
            }

            if(unlink(pid_file) < 0) {
                  cl_log(LOG_INFO, "Could not delete pid-file "
                              "[%s]: %s", pid_file,
                              strerror(errno));
                  return -1;
            }

            if (!bytes) {
                  cl_log(LOG_INFO, "Invalid pid in pid-file "
                              "[%s]: %s", pid_file,
                              strerror(errno));
                  return -1;
            }

            close(pidfilefd);

            pid = strtoul(pidbuf, NULL, 10);
            if (pid == ULONG_MAX && errno == ERANGE) {
                  cl_log(LOG_INFO, "Invalid pid in pid-file "
                              "[%s]: %s", pid_file,
                              strerror(errno));
                  return -1;
            }

            if (kill(pid, SIGKILL) < 0 && errno != ESRCH) {
                  cl_log(LOG_INFO, "Error killing old proccess [%lu] "
                              "from pid-file [%s]: %s", pid,
                              pid_file, strerror(errno));
                  return -1;
            }

            cl_log(LOG_INFO, "Killed old send_arp process [%lu]\n", pid);
      }

      if (snprintf(pidbuf, sizeof(pidbuf), "%u"
      ,     getpid()) >= (int)sizeof(pidbuf)) {
            cl_log(LOG_INFO, "Pid too long for buffer [%u]", getpid());
            return -1;
      }

      while (1) {
            bytes = write(pidfilefd, pidbuf, strlen(pidbuf));
            if (bytes != strlen(pidbuf)) {
                  if (bytes < 0 && errno == EINTR) {
                        continue;
                  }
                  cl_log(LOG_INFO, "Could not write pid-file "
                              "[%s]: %s", pid_file,
                              strerror(errno));
                  return -1;
            }
            break;
      }

      close(pidfilefd);

      return 0;
}

Generated by  Doxygen 1.6.0   Back to index