/src/libpcap/nametoaddr.c

Source
/*
 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998
 *  The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Name to id translation routines used by the scanner.
 * These functions are not time critical.
 */

#include <config.h>

#ifdef _WIN32
  #include <winsock2.h>
  #include <ws2tcpip.h>
#else /* _WIN32 */
  #include <sys/param.h>
  #include <sys/types.h>
  #include <sys/socket.h>
  #include <sys/time.h>

  #include <netinet/in.h>

  #if defined(__linux__) && defined(HAVE_ETHER_HOSTTON)
    #include <features.h>
    #if ! defined(__GLIBC__) && ! defined(__UCLIBC__)
      /*
       * In musl libc (which does not identify itself) ether_hostton() is
       * present and does not work.
       */
      #undef HAVE_ETHER_HOSTTON
    #endif
  #endif // defined(__linux__) && defined(HAVE_ETHER_HOSTTON)

  #ifdef HAVE_ETHER_HOSTTON
    #if defined(NET_ETHERNET_H_DECLARES_ETHER_HOSTTON)
      /*
       * OK, just include <net/ethernet.h>.
       */
      #include <net/ethernet.h>
    #elif defined(NETINET_ETHER_H_DECLARES_ETHER_HOSTTON)
      /*
       * OK, just include <netinet/ether.h>
       */
      #include <netinet/ether.h>
    #elif defined(SYS_ETHERNET_H_DECLARES_ETHER_HOSTTON)
      /*
       * OK, just include <sys/ethernet.h>
       */
      #include <sys/ethernet.h>
    #elif defined(ARPA_INET_H_DECLARES_ETHER_HOSTTON)
      /*
       * OK, just include <arpa/inet.h>
       */
      #include <arpa/inet.h>
    #elif defined(NETINET_IF_ETHER_H_DECLARES_ETHER_HOSTTON)
      /*
       * OK, include <netinet/if_ether.h>, after all the other stuff we
       * need to include or define for its benefit.
       */
      #define NEED_NETINET_IF_ETHER_H
    #else
      /*
       * We'll have to declare it ourselves.
       * If <netinet/if_ether.h> defines struct ether_addr, include
       * it.  Otherwise, define it ourselves.
       */
      #ifdef HAVE_STRUCT_ETHER_ADDR
        #define NEED_NETINET_IF_ETHER_H
      #else /* HAVE_STRUCT_ETHER_ADDR */
  struct ether_addr {
    unsigned char ether_addr_octet[6];
  };
      #endif /* HAVE_STRUCT_ETHER_ADDR */
    #endif /* what declares ether_hostton() */

    #ifdef NEED_NETINET_IF_ETHER_H
      #include <net/if.h> /* Needed on some platforms */
      #include <netinet/in.h> /* Needed on some platforms */
      #include <netinet/if_ether.h>
    #endif /* NEED_NETINET_IF_ETHER_H */

    #ifndef HAVE_DECL_ETHER_HOSTTON
      /*
       * No header declares it, so declare it ourselves.
       */
      extern int ether_hostton(const char *, struct ether_addr *);
    #endif /* !defined(HAVE_DECL_ETHER_HOSTTON) */
  #endif /* HAVE_ETHER_HOSTTON */

  #include <arpa/inet.h>
  #include <netdb.h>
#endif /* _WIN32 */

#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include "pcap-int.h"

#include "diag-control.h"

#include "gencode.h"
#include <pcap/namedb.h>
#include "nametoaddr.h"

#include "thread-local.h"

#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif

#ifndef NTOHL
#define NTOHL(x) (x) = ntohl(x)
#endif

/*
 *  Convert host name to internet address.
 *  Return 0 upon failure.
 *  XXX - not thread-safe; don't use it inside libpcap.
 */
bpf_u_int32 **
pcap_nametoaddr(const char *name)
{
#ifndef h_addr
  static bpf_u_int32 *hlist[2];
#endif
  bpf_u_int32 **p;
  struct hostent *hp;

  /*
   * gethostbyname() is deprecated on Windows, perhaps because
   * it's not thread-safe, or because it doesn't support IPv6,
   * or both.
   *
   * We deprecate pcap_nametoaddr() on all platforms because
   * it's not thread-safe; we supply it for backwards compatibility,
   * so suppress the deprecation warning.  We could, I guess,
   * use getaddrinfo() and construct the array ourselves, but
   * that's probably not worth the effort, as that wouldn't make
   * this thread-safe - we can't change the API to require that
   * our caller free the address array, so we still have to reuse
   * a local array.
   */
DIAG_OFF_DEPRECATION
  if ((hp = gethostbyname(name)) != NULL) {
DIAG_ON_DEPRECATION
#ifndef h_addr
    hlist[0] = (bpf_u_int32 *)hp->h_addr;
    NTOHL(hp->h_addr);
    return hlist;
#else
    for (p = (bpf_u_int32 **)hp->h_addr_list; *p; ++p)
      NTOHL(**p);
    return (bpf_u_int32 **)hp->h_addr_list;
#endif
  }
  else
    return 0;
}

struct addrinfo *
pcap_nametoaddrinfo(const char *name)
{
  struct addrinfo hints, *res;
  int error;

  memset(&hints, 0, sizeof(hints));
  hints.ai_family = PF_UNSPEC;
  hints.ai_socktype = SOCK_STREAM;  /*not really*/
  hints.ai_protocol = IPPROTO_TCP;  /*not really*/
  error = getaddrinfo(name, NULL, &hints, &res);
  if (error)
    return NULL;
  else
    return res;
}

/*
 *  Convert net name to internet address.
 *  Return 0 upon failure.
 *  XXX - not guaranteed to be thread-safe!  See below for platforms
 *  on which it is thread-safe and on which it isn't.
 */
#if defined(_WIN32) || defined(__CYGWIN__)
bpf_u_int32
pcap_nametonetaddr(const char *name _U_)
{
  /*
   * There's no "getnetbyname()" on Windows.
   *
   * XXX - I guess we could use the BSD code to read
   * C:\Windows\System32\drivers\etc/networks, assuming
   * that's its home on all the versions of Windows
   * we use, but that file probably just has the loopback
   * network on 127/24 on 99 44/100% of Windows machines.
   *
   * (Heck, these days it probably just has that on 99 44/100%
   * of *UN*X* machines.)
   */
  return 0;
}
#else /* _WIN32 */
bpf_u_int32
pcap_nametonetaddr(const char *name)
{
  /*
   * UN*X.
   */
  struct netent *np;
  #if defined(HAVE_LINUX_GETNETBYNAME_R)
  /*
   * We have Linux's reentrant getnetbyname_r().
   */
  struct netent result_buf;
  char buf[1024]; /* arbitrary size */
  int h_errnoval;
  int err;

  /*
   * Apparently, the man page at
   *
   *    http://man7.org/linux/man-pages/man3/getnetbyname_r.3.html
   *
   * lies when it says
   *
   *    If the function call successfully obtains a network record,
   *    then *result is set pointing to result_buf; otherwise, *result
   *    is set to NULL.
   *
   * and, in fact, at least in some versions of GNU libc, it does
   * *not* always get set if getnetbyname_r() succeeds.
   */
  np = NULL;
  err = getnetbyname_r(name, &result_buf, buf, sizeof buf, &np,
      &h_errnoval);
  if (err != 0) {
    /*
     * XXX - dynamically allocate the buffer, and make it
     * bigger if we get ERANGE back?
     */
    return 0;
  }
  #elif defined(HAVE_SOLARIS_GETNETBYNAME_R)
  /*
   * We have Solaris's reentrant getnetbyname_r().
   */
  struct netent result_buf;
  char buf[1024]; /* arbitrary size */

  np = getnetbyname_r(name, &result_buf, buf, (int)sizeof buf);
  #elif defined(HAVE_AIX_GETNETBYNAME_R)
  /*
   * We have AIX's reentrant getnetbyname_r().
   */
  struct netent result_buf;
  struct netent_data net_data;

  if (getnetbyname_r(name, &result_buf, &net_data) == -1)
    np = NULL;
  else
    np = &result_buf;
  #else
  /*
   * We don't have any getnetbyname_r(); either we have a
   * getnetbyname() that uses thread-specific data, in which
   * case we're thread-safe (sufficiently recent FreeBSD,
   * sufficiently recent Darwin-based OS, sufficiently recent
   * HP-UX, or we have the
   * traditional getnetbyname() (everything else, including
   * current NetBSD and OpenBSD), in which case we're not
   * thread-safe.
   */
  np = getnetbyname(name);
  #endif
  if (np != NULL)
    return np->n_net;
  else
    return 0;
}
#endif /* _WIN32 */

/*
 * Convert a port name to its port and protocol numbers.
 * We assume only TCP or UDP.
 * Return 0 upon failure.
 */
int
pcap_nametoport(const char *name, int *port, int *proto)
{
  struct addrinfo hints, *res, *ai;
  int error;
  struct sockaddr_in *in4;
  struct sockaddr_in6 *in6;
  int tcp_port = -1;
  int udp_port = -1;

  /*
   * We check for both TCP and UDP in case there are
   * ambiguous entries.
   */
  memset(&hints, 0, sizeof(hints));
  hints.ai_family = PF_UNSPEC;
  hints.ai_socktype = SOCK_STREAM;
  hints.ai_protocol = IPPROTO_TCP;
  error = getaddrinfo(NULL, name, &hints, &res);
  if (error != 0) {
    if (error != EAI_NONAME &&
        error != EAI_SERVICE) {
      /*
       * This is a real error, not just "there's
       * no such service name".
       * XXX - this doesn't return an error string.
       */
      return 0;
    }
  } else {
    /*
     * OK, we found it.  Did it find anything?
     */
    for (ai = res; ai != NULL; ai = ai->ai_next) {
      /*
       * Does it have an address?
       */
      if (ai->ai_addr != NULL) {
        /*
         * Yes.  Get a port number; we're done.
         */
        if (ai->ai_addr->sa_family == AF_INET) {
          in4 = (struct sockaddr_in *)ai->ai_addr;
          tcp_port = ntohs(in4->sin_port);
          break;
        }
        if (ai->ai_addr->sa_family == AF_INET6) {
          in6 = (struct sockaddr_in6 *)ai->ai_addr;
          tcp_port = ntohs(in6->sin6_port);
          break;
        }
      }
    }
    freeaddrinfo(res);
  }

  memset(&hints, 0, sizeof(hints));
  hints.ai_family = PF_UNSPEC;
  hints.ai_socktype = SOCK_DGRAM;
  hints.ai_protocol = IPPROTO_UDP;
  error = getaddrinfo(NULL, name, &hints, &res);
  if (error != 0) {
    if (error != EAI_NONAME &&
        error != EAI_SERVICE) {
      /*
       * This is a real error, not just "there's
       * no such service name".
       * XXX - this doesn't return an error string.
       */
      return 0;
    }
  } else {
    /*
     * OK, we found it.  Did it find anything?
     */
    for (ai = res; ai != NULL; ai = ai->ai_next) {
      /*
       * Does it have an address?
       */
      if (ai->ai_addr != NULL) {
        /*
         * Yes.  Get a port number; we're done.
         */
        if (ai->ai_addr->sa_family == AF_INET) {
          in4 = (struct sockaddr_in *)ai->ai_addr;
          udp_port = ntohs(in4->sin_port);
          break;
        }
        if (ai->ai_addr->sa_family == AF_INET6) {
          in6 = (struct sockaddr_in6 *)ai->ai_addr;
          udp_port = ntohs(in6->sin6_port);
          break;
        }
      }
    }
    freeaddrinfo(res);
  }

  /*
   * We need to check /etc/services for ambiguous entries.
   * If we find an ambiguous entry, and it has the
   * same port number, change the proto to PROTO_UNDEF
   * so both TCP and UDP will be checked.
   */
  if (tcp_port >= 0) {
    *port = tcp_port;
    *proto = IPPROTO_TCP;
    if (udp_port >= 0) {
      if (udp_port == tcp_port)
        *proto = PROTO_UNDEF;
#ifdef notdef
      else
        /* Can't handle ambiguous names that refer
           to different port numbers. */
        warning("ambiguous port %s in /etc/services",
          name);
#endif
    }
    return 1;
  }
  if (udp_port >= 0) {
    *port = udp_port;
    *proto = IPPROTO_UDP;
    return 1;
  }
  return 0;
}

/*
 * Convert a string in the form PPP-PPP, where correspond to ports, to
 * a starting and ending port in a port range.
 * Return 0 on failure.
 */
int
pcap_nametoportrange(const char *name, int *port1, int *port2, int *proto)
{
  char *off, *cpy;
  int save_proto;

  if ((cpy = strdup(name)) == NULL)
    return 0;

  if ((off = strchr(cpy, '-')) == NULL) {
    free(cpy);
    return 0;
  }

  *off = '\0';

  if (pcap_nametoport(cpy, port1, proto) == 0) {
    free(cpy);
    return 0;
  }
  save_proto = *proto;

  if (pcap_nametoport(off + 1, port2, proto) == 0) {
    free(cpy);
    return 0;
  }
  free(cpy);

  if (*proto != save_proto)
    *proto = PROTO_UNDEF;

  return 1;
}

/*
 * XXX - not guaranteed to be thread-safe!  See below for platforms
 * on which it is thread-safe and on which it isn't.
 */
int
pcap_nametoproto(const char *str)
{
  struct protoent *p;
  #if defined(HAVE_LINUX_GETPROTOBYNAME_R)
  /*
   * We have Linux's reentrant getprotobyname_r().
   */
  struct protoent result_buf;
  char buf[1024]; // "...1024 bytes should be sufficient for most applications."
  int err;

  err = getprotobyname_r(str, &result_buf, buf, sizeof buf, &p);
  /*
   * As far as GNU libc implementation goes, an "error" means the
   * protocol database could not be searched, which could mean err ==
   * ERANGE if the buffer is too small or ENOENT if the protocols(5)
   * file does not exist (the man page does not document the latter
   * eventuality).  If the database has been searched normally and the
   * requested protocol name was not found, it is not an "error" and
   * err == 0.
   *
   * This notwithstanding, p == NULL iff a record was not found for any
   * reason (whether an "error" or not), which is the same semantics as
   * in every other HAVE_xxxxx branch of this block.  The final check
   * after the block will catch that if necessary.
   */
  if (err != 0) {
    /*
     * XXX - dynamically allocate the buffer, and make it
     * bigger if we get ERANGE back?
     */
    return PROTO_UNDEF;
  }
  #elif defined(HAVE_SOLARIS_GETPROTOBYNAME_R)
  /*
   * We have Solaris's reentrant getprotobyname_r().
   */
  struct protoent result_buf;
  char buf[1024]; // "...must be at least 1024 bytes."

  p = getprotobyname_r(str, &result_buf, buf, (int)sizeof buf);
  #elif defined(HAVE_AIX_GETPROTOBYNAME_R)
  /*
   * We have AIX's reentrant getprotobyname_r().
   */
  struct protoent result_buf;
  // "The structure must be zero-filled before it is used..." (OpenBSD).
  struct protoent_data proto_data = {0};

  if (getprotobyname_r(str, &result_buf, &proto_data) == -1)
    p = NULL;
  else
    p = &result_buf;
  #else
  /*
   * We don't have any getprotobyname_r(); either we have a
   * getprotobyname() that uses thread-specific data, in which
   * case we're thread-safe (sufficiently recent FreeBSD,
   * sufficiently recent Darwin-based OS, sufficiently recent
   * HP-UX, Windows), or we have
   * the traditional getprotobyname() (everything else, including
   * current NetBSD and OpenBSD), in which case we're not
   * thread-safe.
   */
  p = getprotobyname(str);
  #endif
  if (p != 0)
    return p->p_proto;
  else
    return PROTO_UNDEF;
}

#include "ethertype.h"

struct eproto {
  const char *s;
  u_short p;
};

/*
 * Static data base of ether protocol types.
 * tcpdump used to import this, and it's declared as an export on
 * Debian, at least, so make it a public symbol, even though we
 * don't officially export it by declaring it in a header file.
 * (Programs *should* do this themselves, as tcpdump now does.)
 *
 * We declare it here, right before defining it, to squelch any
 * warnings we might get from compilers about the lack of a
 * declaration.
 */
PCAP_API struct eproto eproto_db[];
PCAP_API_DEF struct eproto eproto_db[] = {
  { "aarp", ETHERTYPE_AARP },
  { "arp", ETHERTYPE_ARP },
  { "atalk", ETHERTYPE_ATALK },
  { "decnet", ETHERTYPE_DN },
  { "ip", ETHERTYPE_IP },
  { "ip6", ETHERTYPE_IPV6 },
  { "lat", ETHERTYPE_LAT },
  { "lldp", ETHERTYPE_LLDP },
  { "loopback", ETHERTYPE_LOOPBACK },
  { "mopdl", ETHERTYPE_MOPDL },
  { "moprc", ETHERTYPE_MOPRC },
  { "rarp", ETHERTYPE_REVARP },
  { "sca", ETHERTYPE_SCA },
  { "slow", ETHERTYPE_SLOW },
  { NULL, 0 }
};

static int
proto_or_undef(const struct eproto *p, const char *s)
{
  while (p->s) {
    if (strcmp(p->s, s) == 0)
      return p->p;
    p += 1;
  }
  return PROTO_UNDEF;
}

int
pcap_nametoeproto(const char *s)
{
  return proto_or_undef(eproto_db, s);
}

#include "llc.h"

/* Static data base of LLC values. */
static struct eproto llc_db[] = {
  { "iso", LLCSAP_ISONS },
  { "stp", LLCSAP_8021D },
  { "ipx", LLCSAP_IPX },
  { "netbeui", LLCSAP_NETBEUI },
  { NULL, 0 }
};

int
pcap_nametollc(const char *s)
{
  return proto_or_undef(llc_db, s);
}

/* Hex digit to 8-bit unsigned integer. */
u_char
pcapint_xdtoi(const u_char c)
{
  if (c >= '0' && c <= '9')
    return (u_char)(c - '0');
  else if (c >= 'a' && c <= 'f')
    return (u_char)(c - 'a' + 10);
  else
    return (u_char)(c - 'A' + 10);
}

int
pcapint_atoin(const char *s, bpf_u_int32 *addr)
{
  u_int n;
  int len;

  *addr = 0;
  len = 0;
  for (;;) {
    n = 0;
    while (*s && *s != '.') {
      if (n > 25) {
        /* The result will be > 255 */
        return -1;
      }
      n = n * 10 + *s++ - '0';
    }
    if (n > 255)
      return -1;
    *addr <<= 8;
    *addr |= n & 0xff;
    len += 8;
    if (*s == '\0')
      return len;
    ++s;
  }
  /* NOTREACHED */
}

/*
 * Iff 's' is a string that is a well-formed DECnet address (aa.nnnn), parse
 * the address into 'addr' and return 1, otherwise return 0.
 *
 * A binary DECnet address consists of a 6-bit area number and a 10-bit node
 * number; neither area 0 nor node 0 are valid for normal addressing purposes,
 * but either can potentially appear on the wire.
 */
int
pcapint_atodn(const char *s, uint16_t *addr)
{
#define AREASHIFT 10
#define AREAMASK 0176000
#define NODEMASK 01777

  /* Initialize to squelch a compiler warning only. */
  u_int node = 0, area = 0;
  /*
   *               +--+             +--+
   *               |  |             |  |
   *               v  |             v  |
   * --> START --> AREA --> DOT --> NODE -->
   *       |          |     |        |
   *       |          v     v        |
   *       +--------> INVALID <------+
   */
  enum {
    START,
    AREA,
    DOT,
    NODE,
    INVALID
  } fsm_state = START;

  while (*s) {
    switch (fsm_state) {
    case START:
      if (PCAP_ISDIGIT(*s)) {
        area = *s - '0';
        fsm_state = AREA;
        break;
      }
      fsm_state = INVALID;
      break;
    case AREA:
      if (*s == '.') {
        fsm_state = DOT;
        break;
      }
      if (PCAP_ISDIGIT(*s)) {
        area = area * 10 + *s - '0';
        if (area <= AREAMASK >> AREASHIFT)
          break;
      }
      fsm_state = INVALID;
      break;
    case DOT:
      if (PCAP_ISDIGIT(*s)) {
        node = *s - '0';
        fsm_state = NODE;
        break;
      }
      fsm_state = INVALID;
      break;
    case NODE:
      if (PCAP_ISDIGIT(*s)) {
        node = node * 10 + *s - '0';
        if (node <= NODEMASK)
          break;
      }
      fsm_state = INVALID;
      break;
    case INVALID:
      return 0;
    } /* switch */
    s++;
  } /* while */
  /*
   * This condition is false if the string comes from the lexer, but
   * let's not depend on that.
   */
  if (fsm_state != NODE)
    return 0;

  // Both 'area' and 'node' have been verified to be in range.
  *addr = (uint16_t)(area << AREASHIFT | node);
  return 1;
}

/*
 * libpcap ARCnet address format is "^\$[0-9a-fA-F]{1,2}$" in regexp syntax.
 * Iff the given string is a well-formed ARCnet address, parse the string,
 * store the 8-bit unsigned value into the provided integer and return 1.
 * Otherwise return 0.
 *
 *  --> START -- $ --> DOLLAR -- [0-9a-fA-F] --> HEX1 -- \0 -->-+
 *        |              |                        |             |
 *       [.]            [.]                  [0-9a-fA-F]        |
 *        |              |                        |             |
 *        v              v                        v             v
 *    (invalid) <--------+-<---------------[.]-- HEX2 -- \0 -->-+--> (valid)
 */
int
pcapint_atoan(const char *s, uint8_t *addr)
{
  enum {
    START,
    DOLLAR,
    HEX1,
    HEX2,
  } fsm_state = START;
  uint8_t tmp = 0;

  while (*s) {
    switch (fsm_state) {
    case START:
      if (*s != '$')
        goto invalid;
      fsm_state = DOLLAR;
      break;
    case DOLLAR:
      if (! PCAP_ISXDIGIT(*s))
        goto invalid;
      tmp = pcapint_xdtoi(*s);
      fsm_state = HEX1;
      break;
    case HEX1:
      if (! PCAP_ISXDIGIT(*s))
        goto invalid;
      tmp <<= 4;
      tmp |= pcapint_xdtoi(*s);
      fsm_state = HEX2;
      break;
    case HEX2:
      goto invalid;
    } // switch
    s++;
  } // while
  if (fsm_state == HEX1 || fsm_state == HEX2) {
    *addr = tmp;
    return 1;
  }

invalid:
  return 0;
}

// Man page: "xxxxxxxxxxxx", regexp: "^[0-9a-fA-F]{12}$".
static u_char
pcapint_atomac48_xxxxxxxxxxxx(const char *s, uint8_t *addr)
{
  if (strlen(s) == 12 &&
      PCAP_ISXDIGIT(s[0]) &&
      PCAP_ISXDIGIT(s[1]) &&
      PCAP_ISXDIGIT(s[2]) &&
      PCAP_ISXDIGIT(s[3]) &&
      PCAP_ISXDIGIT(s[4]) &&
      PCAP_ISXDIGIT(s[5]) &&
      PCAP_ISXDIGIT(s[6]) &&
      PCAP_ISXDIGIT(s[7]) &&
      PCAP_ISXDIGIT(s[8]) &&
      PCAP_ISXDIGIT(s[9]) &&
      PCAP_ISXDIGIT(s[10]) &&
      PCAP_ISXDIGIT(s[11])) {
    addr[0] = pcapint_xdtoi(s[0]) << 4 | pcapint_xdtoi(s[1]);
    addr[1] = pcapint_xdtoi(s[2]) << 4 | pcapint_xdtoi(s[3]);
    addr[2] = pcapint_xdtoi(s[4]) << 4 | pcapint_xdtoi(s[5]);
    addr[3] = pcapint_xdtoi(s[6]) << 4 | pcapint_xdtoi(s[7]);
    addr[4] = pcapint_xdtoi(s[8]) << 4 | pcapint_xdtoi(s[9]);
    addr[5] = pcapint_xdtoi(s[10]) << 4 | pcapint_xdtoi(s[11]);
    return 1;
  }
  return 0;
}

// Man page: "xxxx.xxxx.xxxx", regexp: "^[0-9a-fA-F]{4}(\.[0-9a-fA-F]{4}){2}$".
static u_char
pcapint_atomac48_xxxx_3_times(const char *s, uint8_t *addr)
{
  const char sep = '.';
  if (strlen(s) == 14 &&
      PCAP_ISXDIGIT(s[0]) &&
      PCAP_ISXDIGIT(s[1]) &&
      PCAP_ISXDIGIT(s[2]) &&
      PCAP_ISXDIGIT(s[3]) &&
      s[4] == sep &&
      PCAP_ISXDIGIT(s[5]) &&
      PCAP_ISXDIGIT(s[6]) &&
      PCAP_ISXDIGIT(s[7]) &&
      PCAP_ISXDIGIT(s[8]) &&
      s[9] == sep &&
      PCAP_ISXDIGIT(s[10]) &&
      PCAP_ISXDIGIT(s[11]) &&
      PCAP_ISXDIGIT(s[12]) &&
      PCAP_ISXDIGIT(s[13])) {
    addr[0] = pcapint_xdtoi(s[0]) << 4 | pcapint_xdtoi(s[1]);
    addr[1] = pcapint_xdtoi(s[2]) << 4 | pcapint_xdtoi(s[3]);
    addr[2] = pcapint_xdtoi(s[5]) << 4 | pcapint_xdtoi(s[6]);
    addr[3] = pcapint_xdtoi(s[7]) << 4 | pcapint_xdtoi(s[8]);
    addr[4] = pcapint_xdtoi(s[10]) << 4 | pcapint_xdtoi(s[11]);
    addr[5] = pcapint_xdtoi(s[12]) << 4 | pcapint_xdtoi(s[13]);
    return 1;
  }
  return 0;
}

/*
 * Man page: "xx:xx:xx:xx:xx:xx", regexp: "^[0-9a-fA-F]{1,2}(:[0-9a-fA-F]{1,2}){5}$".
 * Man page: "xx-xx-xx-xx-xx-xx", regexp: "^[0-9a-fA-F]{1,2}(-[0-9a-fA-F]{1,2}){5}$".
 * Man page: "xx.xx.xx.xx.xx.xx", regexp: "^[0-9a-fA-F]{1,2}(\.[0-9a-fA-F]{1,2}){5}$".
 * (Any "xx" above can be "x", which is equivalent to "0x".)
 *
 * An equivalent (and parametrisable for EUI-64) FSM could be implemented using
 * a smaller graph, but that graph would be neither acyclic nor planar nor
 * trivial to verify.
 *
 *                |
 *    [.]         v
 * +<---------- START
 * |              |
 * |              | [0-9a-fA-F]
 * |  [.]         v
 * +<--------- BYTE0_X ----------+
 * |              |              |
 * |              | [0-9a-fA-F]  |
 * |  [.]         v              |
 * +<--------- BYTE0_XX          | [:\.-]
 * |              |              |
 * |              | [:\.-]       |
 * |  [.]         v              |
 * +<----- BYTE0_SEP_BYTE1 <-----+
 * |              |
 * |              | [0-9a-fA-F]
 * |  [.]         v
 * +<--------- BYTE1_X ----------+
 * |              |              |
 * |              | [0-9a-fA-F]  |
 * |  [.]         v              |
 * +<--------- BYTE1_XX          | <sep>
 * |              |              |
 * |              | <sep>        |
 * |  [.]         v              |
 * +<----- BYTE1_SEP_BYTE2 <-----+
 * |              |
 * |              | [0-9a-fA-F]
 * |  [.]         v
 * +<--------- BYTE2_X ----------+
 * |              |              |
 * |              | [0-9a-fA-F]  |
 * |  [.]         v              |
 * +<--------- BYTE2_XX          | <sep>
 * |              |              |
 * |              | <sep>        |
 * |  [.]         v              |
 * +<----- BYTE2_SEP_BYTE3 <-----+
 * |              |
 * |              | [0-9a-fA-F]
 * |  [.]         v
 * +<--------- BYTE3_X ----------+
 * |              |              |
 * |              | [0-9a-fA-F]  |
 * |  [.]         v              |
 * +<--------- BYTE3_XX          | <sep>
 * |              |              |
 * |              | <sep>        |
 * |  [.]         v              |
 * +<----- BYTE3_SEP_BYTE4 <-----+
 * |              |
 * |              | [0-9a-fA-F]
 * |  [.]         v
 * +<--------- BYTE4_X ----------+
 * |              |              |
 * |              | [0-9a-fA-F]  |
 * |  [.]         v              |
 * +<--------- BYTE4_XX          | <sep>
 * |              |              |
 * |              | <sep>        |
 * |  [.]         v              |
 * +<----- BYTE4_SEP_BYTE5 <-----+
 * |              |
 * |              | [0-9a-fA-F]
 * |  [.]         v
 * +<--------- BYTE5_X ----------+
 * |              |              |
 * |              | [0-9a-fA-F]  |
 * |  [.]         v              |
 * +<--------- BYTE5_XX          | \0
 * |              |              |
 * |              | \0           |
 * |              |              v
 * +--> (reject)  +---------> (accept)
 *
 */
static u_char
pcapint_atomac48_x_xx_6_times(const char *s, uint8_t *addr)
{
  enum {
    START,
    BYTE0_X,
    BYTE0_XX,
    BYTE0_SEP_BYTE1,
    BYTE1_X,
    BYTE1_XX,
    BYTE1_SEP_BYTE2,
    BYTE2_X,
    BYTE2_XX,
    BYTE2_SEP_BYTE3,
    BYTE3_X,
    BYTE3_XX,
    BYTE3_SEP_BYTE4,
    BYTE4_X,
    BYTE4_XX,
    BYTE4_SEP_BYTE5,
    BYTE5_X,
    BYTE5_XX,
  } fsm_state = START;
  uint8_t buf[6];
  const char *seplist = ":.-";
  /*
   * XXX - the state diagram indicates that we cannot get to states
   * BYTEn_X or BYTEn_XX, for n > 0, without first going through
   * states BYTE0_X or BYTE0_XX, but at least some versions of
   * MSVC complain that sep may be used uninitialized, so we
   * initialize it here.
   */
  char sep = '\0';

  while (*s) {
    switch (fsm_state) {
    case START:
      if (PCAP_ISXDIGIT(*s)) {
        buf[0] = pcapint_xdtoi(*s);
        fsm_state = BYTE0_X;
        break;
      }
      goto reject;
    case BYTE0_X:
      if (strchr(seplist, *s)) {
        sep = *s;
        fsm_state = BYTE0_SEP_BYTE1;
        break;
      }
      if (PCAP_ISXDIGIT(*s)) {
        buf[0] = buf[0] << 4 | pcapint_xdtoi(*s);
        fsm_state = BYTE0_XX;
        break;
      }
      goto reject;
    case BYTE0_XX:
      if (strchr(seplist, *s)) {
        sep = *s;
        fsm_state = BYTE0_SEP_BYTE1;
        break;
      }
      goto reject;
    case BYTE0_SEP_BYTE1:
      if (PCAP_ISXDIGIT(*s)) {
        buf[1] = pcapint_xdtoi(*s);
        fsm_state = BYTE1_X;
        break;
      }
      goto reject;
    case BYTE1_X:
      if (*s == sep) {
        fsm_state = BYTE1_SEP_BYTE2;
        break;
      }
      if (PCAP_ISXDIGIT(*s)) {
        buf[1] = buf[1] << 4 | pcapint_xdtoi(*s);
        fsm_state = BYTE1_XX;
        break;
      }
      goto reject;
    case BYTE1_XX:
      if (*s == sep) {
        fsm_state = BYTE1_SEP_BYTE2;
        break;
      }
      goto reject;
    case BYTE1_SEP_BYTE2:
      if (PCAP_ISXDIGIT(*s)) {
        buf[2] = pcapint_xdtoi(*s);
        fsm_state = BYTE2_X;
        break;
      }
      goto reject;
    case BYTE2_X:
      if (*s == sep) {
        fsm_state = BYTE2_SEP_BYTE3;
        break;
      }
      if (PCAP_ISXDIGIT(*s)) {
        buf[2] = buf[2] << 4 | pcapint_xdtoi(*s);
        fsm_state = BYTE2_XX;
        break;
      }
      goto reject;
    case BYTE2_XX:
      if (*s == sep) {
        fsm_state = BYTE2_SEP_BYTE3;
        break;
      }
      goto reject;
    case BYTE2_SEP_BYTE3:
      if (PCAP_ISXDIGIT(*s)) {
        buf[3] = pcapint_xdtoi(*s);
        fsm_state = BYTE3_X;
        break;
      }
      goto reject;
    case BYTE3_X:
      if (*s == sep) {
        fsm_state = BYTE3_SEP_BYTE4;
        break;
      }
      if (PCAP_ISXDIGIT(*s)) {
        buf[3] = buf[3] << 4 | pcapint_xdtoi(*s);
        fsm_state = BYTE3_XX;
        break;
      }
      goto reject;
    case BYTE3_XX:
      if (*s == sep) {
        fsm_state = BYTE3_SEP_BYTE4;
        break;
      }
      goto reject;
    case BYTE3_SEP_BYTE4:
      if (PCAP_ISXDIGIT(*s)) {
        buf[4] = pcapint_xdtoi(*s);
        fsm_state = BYTE4_X;
        break;
      }
      goto reject;
    case BYTE4_X:
      if (*s == sep) {
        fsm_state = BYTE4_SEP_BYTE5;
        break;
      }
      if (PCAP_ISXDIGIT(*s)) {
        buf[4] = buf[4] << 4 | pcapint_xdtoi(*s);
        fsm_state = BYTE4_XX;
        break;
      }
      goto reject;
    case BYTE4_XX:
      if (*s == sep) {
        fsm_state = BYTE4_SEP_BYTE5;
        break;
      }
      goto reject;
    case BYTE4_SEP_BYTE5:
      if (PCAP_ISXDIGIT(*s)) {
        buf[5] = pcapint_xdtoi(*s);
        fsm_state = BYTE5_X;
        break;
      }
      goto reject;
    case BYTE5_X:
      if (PCAP_ISXDIGIT(*s)) {
        buf[5] = buf[5] << 4 | pcapint_xdtoi(*s);
        fsm_state = BYTE5_XX;
        break;
      }
      goto reject;
    case BYTE5_XX:
      goto reject;
    } // switch
    s++;
  } // while

  if (fsm_state == BYTE5_X || fsm_state == BYTE5_XX) {
    // accept
    memcpy(addr, buf, sizeof(buf));
    return 1;
  }

reject:
  return 0;
}

// The 'addr' argument must point to an array of at least 6 elements.
int
pcapint_atomac48(const char *s, uint8_t *addr)
{
  return s && (
      pcapint_atomac48_xxxxxxxxxxxx(s, addr) ||
      pcapint_atomac48_xxxx_3_times(s, addr) ||
      pcapint_atomac48_x_xx_6_times(s, addr)
  );
}

/*
 * If 's' is a MAC-48 address in one of the forms documented in pcap-filter(7)
 * for "ether host", return a pointer to an allocated buffer with the binary
 * value of the address.  Return NULL on any error.
 */
u_char *
pcap_ether_aton(const char *s)
{
  uint8_t tmp[6];
  if (! pcapint_atomac48(s, tmp))
    return (NULL);

  u_char *e = malloc(6);
  if (e == NULL)
    return (NULL);
  memcpy(e, tmp, sizeof(tmp));
  return (e);
}

#ifndef HAVE_ETHER_HOSTTON
/*
 * Roll our own.
 *
 * This should be thread-safe, as we define the static variables
 * we use to be thread-local, and as pcap_next_etherent() does so
 * as well.
 */
u_char *
pcap_ether_hostton(const char *name)
{
  struct pcap_etherent *ep;
  u_char *ap;
  static thread_local FILE *fp = NULL;
  static thread_local int init = 0;

  if (!init) {
    fp = fopen(PCAP_ETHERS_FILE, "r");
    ++init;
    if (fp == NULL)
      return (NULL);
  } else if (fp == NULL)
    return (NULL);
  else
    rewind(fp);

  while ((ep = pcap_next_etherent(fp)) != NULL) {
    if (strcmp(ep->name, name) == 0) {
      ap = (u_char *)malloc(6);
      if (ap != NULL) {
        memcpy(ap, ep->addr, 6);
        return (ap);
      }
      break;
    }
  }
  return (NULL);
}
#else
/*
 * Use the OS-supplied routine.
 * This *should* be thread-safe; the API doesn't have a static buffer.
 */
u_char *
pcap_ether_hostton(const char *name)
{
  u_char *ap;
  u_char a[6];
  char namebuf[1024];

  /*
   * In AIX 7.1 and 7.2: int ether_hostton(char *, struct ether_addr *);
   */
  pcapint_strlcpy(namebuf, name, sizeof(namebuf));
  ap = NULL;
  if (ether_hostton(namebuf, (struct ether_addr *)a) == 0) {
    ap = (u_char *)malloc(6);
    if (ap != NULL)
      memcpy((char *)ap, (char *)a, 6);
  }
  return (ap);
}
#endif

Coverage Report

Created: 2026-08-15 06:53