su_addrinfo.c

sip协议栈

get_name(addr, gai_afd, res, numaddr, pai, port0)
	const char *addr;
	struct gai_afd *gai_afd;
	struct addrinfo **res;
	char *numaddr;
	struct addrinfo *pai;
	int port0;
{
	u_short port = port0 & 0xffff;
	struct hostent *hp;
	struct addrinfo *cur;
	int error = 0, h_error;
	
#if SU_HAVE_IN6
	hp = getipnodebyaddr(addr, gai_afd->a_addrlen, gai_afd->a_af, &h_error);
#else
	hp = gethostbyaddr(addr, gai_afd->a_addrlen, AF_INET);
#endif
	if (hp && hp->h_name && hp->h_name[0] && hp->h_addr_list[0]) {
		GET_AI(cur, gai_afd, hp->h_addr_list[0], port);
		GET_CANONNAME(cur, hp->h_name);
	} else
		GET_AI(cur, gai_afd, numaddr, port);
	
#if SU_HAVE_IN6
	if (hp)
		freehostent(hp);
#endif
	*res = cur;
	return SUCCESS;
 free:
	if (cur)
		freeaddrinfo(cur);
#if SU_HAVE_IN6
	if (hp)
		freehostent(hp);
#endif
 /* bad: */
	*res = NULL;
	return error;
}

static int
get_addr(hostname, af, res, pai, port0)
	const char *hostname;
	int af;
	struct addrinfo **res;
	struct addrinfo *pai;
	int port0;
{
	u_short port = port0 & 0xffff;
	struct addrinfo sentinel;
	struct hostent *hp;
	struct addrinfo *top, *cur;
	struct gai_afd *gai_afd;
	int i, error = 0, h_error;
	char *ap;

	top = NULL;
	sentinel.ai_next = NULL;
	cur = &sentinel;
#if SU_HAVE_IN6
	if (af == AF_UNSPEC) {
		hp = getipnodebyname(hostname, AF_INET6,
				AI_ADDRCONFIG|AI_ALL|AI_V4MAPPED, &h_error);
	} else
		hp = getipnodebyname(hostname, af, AI_ADDRCONFIG, &h_error);
#else
	hp = gethostbyname(hostname);
	h_error = h_errno;
#endif
	if (hp == NULL) {
		switch (h_error) {
		case HOST_NOT_FOUND:
		case NO_DATA:
			error = EAI_NODATA;
			break;
		case TRY_AGAIN:
			error = EAI_AGAIN;
			break;
		case NO_RECOVERY:
		default:
			error = EAI_FAIL;
			break;
		}
		goto bad;
	}

	if ((hp->h_name == NULL) || (hp->h_name[0] == 0) ||
	    (hp->h_addr_list[0] == NULL))
		ERR(EAI_FAIL);
	
	for (i = 0; (ap = hp->h_addr_list[i]) != NULL; i++) {
		switch (af) {
#if SU_HAVE_IN6
		case AF_INET6:
			gai_afd = &gai_afdl[N_INET6];
			break;
#endif
#ifndef INET6
		default:	/* AF_UNSPEC */
#endif
		case AF_INET:
			gai_afd = &gai_afdl[N_INET];
			break;
#if SU_HAVE_IN6
		default:	/* AF_UNSPEC */
			if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) {
				ap += sizeof(struct in6_addr) -
					sizeof(struct in_addr);
				gai_afd = &gai_afdl[N_INET];
			} else
				gai_afd = &gai_afdl[N_INET6];
			break;
#endif
		}
#ifdef FAITH
		if (translate && gai_afd->a_af == AF_INET) {
			struct in6_addr *in6;

			GET_AI(cur->ai_next, &gai_afdl[N_INET6], ap, port);
			in6 = &((struct sockaddr_in6 *)cur->ai_next->ai_addr)->sin6_addr;
			memcpy(&in6->s6_addr32[0], &faith_prefix,
			    sizeof(struct in6_addr) - sizeof(struct in_addr));
			memcpy(&in6->s6_addr32[3], ap, sizeof(struct in_addr));
		} else
#endif /* FAITH */
		GET_AI(cur->ai_next, gai_afd, ap, port);
		if (cur == &sentinel) {
			top = cur->ai_next;
			GET_CANONNAME(top, hp->h_name);
		}
		cur = cur->ai_next;
	}
#if SU_HAVE_IN6
	freehostent(hp);
#endif
	*res = top;
	return SUCCESS;
 free:
	if (top)
		freeaddrinfo(top);
#if SU_HAVE_IN6
	if (hp)
		freehostent(hp);
#endif
 bad:
	*res = NULL;
	return error;
}

/*
 * Issues to be discussed:
 * - Thread safe-ness must be checked
 * - Return values.  There seems to be no standard for return value (RFC2133)
 *   but INRIA implementation returns EAI_xxx defined for getaddrinfo().
 */

#define SUCCESS 0
#define YES 1
#define NO  0

static struct gni_afd {
	int a_af;
	int a_addrlen;
	int a_socklen;
	int a_off;
} gni_afdl [] = {
#if SU_HAVE_IN6
	{PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
		offsetof(struct sockaddr_in6, sin6_addr)},
#endif
	{PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
		offsetof(struct sockaddr_in, sin_addr)},
	{0, 0, 0},
};

struct gni_sockinet {
	u_char	si_len;
	u_char	si_family;
	u_short	si_port;
};

#define ENI_NOSOCKET 	EAI_FAIL
#define ENI_NOSERVNAME	EAI_NONAME
#define ENI_NOHOSTNAME	EAI_NONAME
#define ENI_MEMORY	EAI_MEMORY
#define ENI_SYSTEM	EAI_SYSTEM
#define ENI_FAMILY	EAI_FAMILY
#define ENI_SALEN	EAI_MEMORY

static
int
getnameinfo(sa, salen, host, hostlen, serv, servlen, flags)
	const struct sockaddr *sa;
	size_t salen;
	char *host;
	size_t hostlen;
	char *serv;
	size_t servlen;
	int flags;
{
	struct gni_afd *gni_afd;
	struct servent *sp;
	struct hostent *hp;
	u_short port;
	int family, len, i;
	char *addr, *p;
	u_long v4a;
	u_char pfx;
	int h_error;
	char numserv[512];
	char numaddr[512];

	if (sa == NULL)
		return ENI_NOSOCKET;

#if SU_HAVE_SOCKADDR_SA_LEN
	len = sa->sa_len;
	if (len != salen) return ENI_SALEN;
#else
	len = salen;
#endif
	
	family = sa->sa_family;
	for (i = 0; gni_afdl[i].a_af; i++)
		if (gni_afdl[i].a_af == family) {
			gni_afd = &gni_afdl[i];
			goto found;
		}
	return ENI_FAMILY;
	
 found:
	if (len != gni_afd->a_socklen) return ENI_SALEN;
	
	port = ((struct gni_sockinet *)sa)->si_port; /* network byte order */
	addr = (char *)sa + gni_afd->a_off;

	if (serv == NULL || servlen == 0) {
		/* what we should do? */
	} else if (flags & NI_NUMERICSERV) {
		snprintf(numserv, sizeof(numserv), "%d", ntohs(port));
		if (strlen(numserv) > servlen)
			return ENI_MEMORY;
		strcpy(serv, numserv);
	} else {
		sp = getservbyport(port, (flags & NI_DGRAM) ? "udp" : "tcp");
		if (sp) {
			if (strlen(sp->s_name) > servlen)
				return ENI_MEMORY;
			strcpy(serv, sp->s_name);
		} else
			return ENI_NOSERVNAME;
	}

	switch (sa->sa_family) {
	case AF_INET:
		v4a = ((struct sockaddr_in *)sa)->sin_addr.s_addr;
		if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
			flags |= NI_NUMERICHOST;
		v4a >>= IN_CLASSA_NSHIFT;
		if (v4a == 0 || v4a == IN_LOOPBACKNET)
			flags |= NI_NUMERICHOST;			
		break;
#if SU_HAVE_IN6
	case AF_INET6:
		pfx = ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr8[0];
		if (pfx == 0 || pfx == 0xfe || pfx == 0xff)
			flags |= NI_NUMERICHOST;
		break;
#endif
	}
	if (host == NULL || hostlen == 0) {
		/* what should we do? */
	} else if (flags & NI_NUMERICHOST) {
		if (inet_ntop(gni_afd->a_af, addr, numaddr, sizeof(numaddr))
		    == NULL)
			return ENI_SYSTEM;
		if (strlen(numaddr) > hostlen)
			return ENI_MEMORY;
		strcpy(host, numaddr);
	} else {
#if SU_HAVE_IN6
		hp = getipnodebyaddr(addr, gni_afd->a_addrlen, gni_afd->a_af, &h_error);
#else
		hp = gethostbyaddr(addr, gni_afd->a_addrlen, gni_afd->a_af);
		h_error = h_errno;
#endif

		if (hp) {
			if (flags & NI_NOFQDN) {
				p = strchr(hp->h_name, '.');
				if (p) *p = '\0';
			}
			if (strlen(hp->h_name) > hostlen) {
#if SU_HAVE_IN6
				freehostent(hp);
#endif
				return ENI_MEMORY;
			}
			strcpy(host, hp->h_name);
#if SU_HAVE_IN6
			freehostent(hp);
#endif
		} else {
			if (flags & NI_NAMEREQD)
				return ENI_NOHOSTNAME;
			if (inet_ntop(gni_afd->a_af, addr, numaddr, sizeof(numaddr))
			    == NULL)
				return ENI_NOHOSTNAME;
			if (strlen(numaddr) > hostlen)
				return ENI_MEMORY;
			strcpy(host, numaddr);
		}
	}
	return SUCCESS;
}

#endif	/* !HAVE_GETNAMEINFO */

#if !HAVE_FREEADDRINFO
static 
void
freeaddrinfo(ai)
	struct addrinfo *ai;
{
	struct addrinfo *next;

	do {
		next = ai->ai_next;
		if (ai->ai_canonname)
			free(ai->ai_canonname);
		/* no need to free(ai->ai_addr) */
		free(ai);
	} while ((ai = next) != NULL);
}
#endif

#if !HAVE_GAI_STRERROR
static 
char *
gai_strerror(ecode)
	int ecode;
{
  switch (ecode) {
  case 0: 
    return "success.";
#if defined(EAI_ADDRFAMILY)
  case EAI_ADDRFAMILY:
    return "address family for hostname not supported.";
#endif
#if defined(EAI_AGAIN)
  case EAI_AGAIN:
    return "temporary failure in name resolution.";
#endif
#if defined(EAI_BADFLAGS)
  case EAI_BADFLAGS:
    return "invalid value for ai_flags.";
#endif
#if defined(EAI_FAIL)
  case EAI_FAIL:
    return "non-recoverable failure in name resolution.";
#endif
#if defined(EAI_FAMILY)
  case EAI_FAMILY:
    return "ai_family not supported.";
#endif
#if defined(EAI_MEMORY)
  case EAI_MEMORY:
    return "memory allocation failure.";
#endif
#if defined(EAI_NODATA)
  case EAI_NODATA:
    return "no address associated with hostname.";
#endif
#if defined(EAI_NONAME)
  case EAI_NONAME:
    return "hostname nor servname provided, or not known.";
#endif
#if defined(EAI_SERVICE)
  case EAI_SERVICE:
    return "servname not supported for ai_socktype.";
#endif
#if defined(EAI_SOCKTYPE)
  case EAI_SOCKTYPE:
    return "ai_socktype not supported.";
#endif
#if defined(EAI_SYSTEM)
  case EAI_SYSTEM:
    return "system error returned in errno.";
#endif
#if defined(EAI_BADHINTS)
  case EAI_BADHINTS:
    return "invalid value for hints.";
#endif
#if defined(EAI_PROTOCOL)
  case EAI_PROTOCOL:
    return "resolved protocol is unknown.";
#endif
  default:
    return "unknown error.";
  }
}
#endif


/** Translate address and service.
 *
 * This is a getaddrinfo() supporting SCTP and other exotic protocols.
 */
int su_getaddrinfo(char const *node, char const *service,
		   su_addrinfo_t const *hints,
		   su_addrinfo_t **res)
{
#if HAVE_SCTP
  if (res && hints && hints->ai_protocol == IPPROTO_SCTP) {
    su_addrinfo_t *ai, system_hints[1];
    int retval, socktype;

    socktype = hints->ai_socktype;
    
    if (!(socktype == 0 ||
	  socktype == SOCK_SEQPACKET ||
	  socktype == SOCK_STREAM ||
	  socktype == SOCK_DGRAM))
      return EAI_SOCKTYPE;

    *system_hints = *hints;
    system_hints->ai_protocol = IPPROTO_TCP;
    system_hints->ai_socktype = SOCK_STREAM;

    retval = getaddrinfo(node, service, system_hints, res);
    if (retval)
      return retval;

    if (socktype == 0)
      socktype = SOCK_STREAM;

    for (ai = *res; ai; ai = ai->ai_next) {
      ai->ai_protocol = IPPROTO_SCTP;
      ai->ai_socktype = socktype;
    }

    return 0;
  }
#endif

  return getaddrinfo(node, service, hints, res);
}

/** Free su_addrinfo_t structure allocated by su_getaddrinfo(). */
void su_freeaddrinfo(su_addrinfo_t *res)
{
  freeaddrinfo(res);
}

/** Return string describing address translation error. */
char const *su_gai_strerror(int errcode)
{
  return gai_strerror(errcode);
}

/** Resolve socket address into hostname and service name */
int
su_getnameinfo(const su_sockaddr_t *su, size_t sulen,
	       char *return_host, size_t hostlen,
	       char *return_serv, size_t servlen,
	       int flags)
{
  return getnameinfo(&su->su_sa, sulen, 
		     return_host, hostlen, 
		     return_serv, servlen, 
		     flags);
}