resolv.c

Axis 221 camera embedded programing interface

	/*
	 * if we got here, we didn't satisfy the search.
	 * if we did an initial full query, return that query's h_errno
	 * (note that we wouldn't be here if that query had succeeded).
	 * else if we ever got a nodata, send that back as the reason.
	 * else send back meaningless h_errno, that being the one from
	 * the last DNSRCH we did.
	 */
	if (saved_herrno != -1)
		h_errno = saved_herrno;
	else if (got_nodata)
		h_errno = NO_DATA;
	else if (got_servfail)
		h_errno = TRY_AGAIN;
	return (-1);
}

/*
 * Perform a call on res_query on the concatenation of name and domain,
 * removing a trailing dot from name if domain is NULL.
 */
int res_querydomain(name, domain, class, type, answer, anslen)
	const char *name, *domain;
	int class, type;	/* class and type of query */
	u_char *answer;		/* buffer to put answer */
	int anslen;		/* size of answer */
{
	char nbuf[MAXDNAME];
	const char *longname = nbuf;
	size_t n, d;

	if ((!name || !answer) || ((_res.options & RES_INIT) == 0 && res_init() == -1)) {
		h_errno = NETDB_INTERNAL;
		return (-1);
	}

#ifdef DEBUG
	if (_res.options & RES_DEBUG)
		printf(";; res_querydomain(%s, %s, %d, %d)\n",
			name, domain?domain:"<Nil>", class, type);
#endif
	if (domain == NULL) {
		/*
		 * Check for trailing '.';
		 * copy without '.' if present.
		 */
		n = strlen(name);
		if (n + 1 > sizeof(nbuf)) {
			h_errno = NO_RECOVERY;
			return (-1);
		}
		if (n > 0 && name[--n] == '.') {
			strncpy(nbuf, name, n);
			nbuf[n] = '\0';
		} else
			longname = name;
	} else {
		n = strlen(name);
		d = strlen(domain);
		if (n + 1 + d + 1 > sizeof(nbuf)) {
			h_errno = NO_RECOVERY;
			return (-1);
		}
		snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain);
	}
	return (res_query(longname, class, type, answer, anslen));
}

/* res_mkquery */
/* res_send */
/* dn_comp */
/* dn_expand */
#endif

#ifdef L_gethostbyaddr
struct hostent *gethostbyaddr (const void *addr, socklen_t len, int type)
{
	static struct hostent h;
	static char buf[
#ifndef __UCLIBC_HAS_IPV6__
		sizeof(struct in_addr) + sizeof(struct in_addr *)*2 +
#else
		sizeof(struct in6_addr) + sizeof(struct in6_addr *)*2 +
#endif /* __UCLIBC_HAS_IPV6__ */
		sizeof(char *)*(ALIAS_DIM) + 256/*namebuffer*/ + 32/* margin */];
	struct hostent *hp;

	gethostbyaddr_r(addr, len, type, &h, buf, sizeof(buf), &hp, &h_errno);
        
	return hp;
}
#endif


#ifdef L_read_etc_hosts_r

void __open_etc_hosts(FILE **fp)
{
	if ((*fp = fopen("/etc/hosts", "r")) == NULL) {
		*fp = fopen("/etc/config/hosts", "r");
	}
	return;
}

int __read_etc_hosts_r(FILE * fp, const char * name, int type,
		     enum etc_hosts_action action,
		     struct hostent * result_buf,
		     char * buf, size_t buflen,
		     struct hostent ** result,
		     int * h_errnop)
{
	struct in_addr	*in=NULL;
	struct in_addr	**addr_list=NULL;
#ifdef __UCLIBC_HAS_IPV6__
	struct in6_addr	*in6=NULL;
	struct in6_addr	**addr_list6=NULL;
#endif /* __UCLIBC_HAS_IPV6__ */
	char					*cp;
	char					**alias;
	int						aliases, i;
	int		ret=HOST_NOT_FOUND;

	if (buflen < sizeof(char *)*(ALIAS_DIM))
		return ERANGE;
	alias=(char **)buf;
	buf+=sizeof(char **)*(ALIAS_DIM);
	buflen-=sizeof(char **)*(ALIAS_DIM);

	if (action!=GETHOSTENT) {
#ifdef __UCLIBC_HAS_IPV6__
		char *p=buf;
		size_t len=buflen;
#endif /* __UCLIBC_HAS_IPV6__ */
		*h_errnop=NETDB_INTERNAL;
		if (buflen < sizeof(*in))
			return ERANGE;
		in=(struct in_addr*)buf;
		buf+=sizeof(*in);
		buflen-=sizeof(*in);

		if (buflen < sizeof(*addr_list)*2)
			return ERANGE;
		addr_list=(struct in_addr **)buf;
		buf+=sizeof(*addr_list)*2;
		buflen-=sizeof(*addr_list)*2;

#ifdef __UCLIBC_HAS_IPV6__
		if (len < sizeof(*in6))
			return ERANGE;
		in6=(struct in6_addr*)p;
		p+=sizeof(*in6);
		len-=sizeof(*in6);

		if (len < sizeof(*addr_list6)*2)
			return ERANGE;
		addr_list6=(struct in6_addr**)p;
		p+=sizeof(*addr_list6)*2;
		len-=sizeof(*addr_list6)*2;

		if (len < buflen) {
			buflen=len;
			buf=p;
		}
#endif /* __UCLIBC_HAS_IPV6__ */

		if (buflen < 80)
			return ERANGE;

		__open_etc_hosts(&fp);
		if (fp == NULL) {
			result=NULL;
			return errno;
		}
	}

	*h_errnop=HOST_NOT_FOUND;
	while (fgets(buf, buflen, fp)) {
		if ((cp = strchr(buf, '#')))
			*cp = '\0';
		DPRINTF("Looking at: %s\n", buf);
		aliases = 0;

		cp = buf;
		while (*cp) {
			while (*cp && isspace(*cp))
				*cp++ = '\0';
			if (!*cp)
				continue;
			if (aliases < (2+MAX_ALIASES))
				alias[aliases++] = cp;
			while (*cp && !isspace(*cp))
				cp++;
		}
		alias[aliases] = 0;

		if (aliases < 2)
			continue; /* syntax error really */
		
		if (action==GETHOSTENT) {
			/* Return whatever the next entry happens to be. */
			break;
		} else if (action==GET_HOSTS_BYADDR) {
			if (strcmp(name, alias[0]) != 0)
				continue;
		} else {
			/* GET_HOSTS_BYNAME */
			for (i = 1; i < aliases; i++)
				if (strcasecmp(name, alias[i]) == 0)
					break;
			if (i >= aliases)
				continue;
		}

		if (type == AF_INET && inet_pton(AF_INET, alias[0], in) > 0) {
			DPRINTF("Found INET\n");
			addr_list[0] = in;
			addr_list[1] = 0;
			result_buf->h_name = alias[1];
			result_buf->h_addrtype = AF_INET;
			result_buf->h_length = sizeof(*in);
			result_buf->h_addr_list = (char**) addr_list;
			result_buf->h_aliases = alias + 2;
			*result=result_buf;
			ret=NETDB_SUCCESS;
#ifdef __UCLIBC_HAS_IPV6__
        } else if (type == AF_INET6 && inet_pton(AF_INET6, alias[0], in6) > 0) {
			DPRINTF("Found INET6\n");
			addr_list6[0] = in6;
			addr_list6[1] = 0;
			result_buf->h_name = alias[1];
			result_buf->h_addrtype = AF_INET6;
			result_buf->h_length = sizeof(*in6);
			result_buf->h_addr_list = (char**) addr_list6;
			result_buf->h_aliases = alias + 2;
			*result=result_buf;
			ret=NETDB_SUCCESS;
#endif /* __UCLIBC_HAS_IPV6__ */
		} else {
			DPRINTF("Error\n");
			ret=TRY_AGAIN;
			break; /* bad ip address */
        }
        
		if (action!=GETHOSTENT) {
			fclose(fp);
		}
		return ret;
	}
	if (action!=GETHOSTENT) {
		fclose(fp);
	}
	return ret;
}
#endif


#ifdef L_gethostent

#ifdef __UCLIBC_HAS_THREADS__
static pthread_mutex_t mylock = PTHREAD_MUTEX_INITIALIZER;
# define LOCK	__pthread_mutex_lock(&mylock)
# define UNLOCK	__pthread_mutex_unlock(&mylock);
#else
# define LOCK
# define UNLOCK
#endif

static int __stay_open;
static FILE * __gethostent_fp;

void endhostent (void)
{
    LOCK;
    __stay_open = 0;
    if (__gethostent_fp) {
	fclose(__gethostent_fp);
    }
    UNLOCK;
}

void sethostent (int stay_open)
{
    LOCK;
    __stay_open = stay_open;
    UNLOCK;
}

int gethostent_r(struct hostent *result_buf, char *buf, size_t buflen,
	struct hostent **result, int *h_errnop)
{
    int ret;

    LOCK;
    if (__gethostent_fp == NULL) {
	__open_etc_hosts(&__gethostent_fp);
	if (__gethostent_fp == NULL) {
	    UNLOCK;
	    *result=NULL;
	    return 0;
	}
    }

    ret = __read_etc_hosts_r(__gethostent_fp, NULL, AF_INET, GETHOSTENT, 
		   result_buf, buf, buflen, result, h_errnop);
    if (__stay_open==0) {
	fclose(__gethostent_fp);
    }
    UNLOCK;
    return(ret);
}

struct hostent *gethostent (void)
{
    static struct hostent h;
    static char buf[
#ifndef __UCLIBC_HAS_IPV6__
	    sizeof(struct in_addr) + sizeof(struct in_addr *)*2 +
#else
	    sizeof(struct in6_addr) + sizeof(struct in6_addr *)*2 +
#endif /* __UCLIBC_HAS_IPV6__ */
		sizeof(char *)*(ALIAS_DIM) +
	    80/*namebuffer*/ + 2/* margin */];
    struct hostent *host;

    LOCK;
    gethostent_r(&h, buf, sizeof(buf), &host, &h_errno);
    UNLOCK;
    return(host);
}
#endif

#ifdef L_get_hosts_byname_r

int __get_hosts_byname_r(const char * name, int type,
			    struct hostent * result_buf,
			    char * buf, size_t buflen,
			    struct hostent ** result,
			    int * h_errnop)
{
	return(__read_etc_hosts_r(NULL, name, type, GET_HOSTS_BYNAME, result_buf, buf, buflen, result, h_errnop));
}
#endif

#ifdef L_get_hosts_byaddr_r

int __get_hosts_byaddr_r(const char * addr, int len, int type,
			    struct hostent * result_buf,
			    char * buf, size_t buflen,
			    struct hostent ** result,
			    int * h_errnop)
{
#ifndef __UCLIBC_HAS_IPV6__
	char	ipaddr[INET_ADDRSTRLEN];
#else
	char	ipaddr[INET6_ADDRSTRLEN];
#endif /* __UCLIBC_HAS_IPV6__ */

    switch (type) {
	case AF_INET:
		if (len != sizeof(struct in_addr))
			return 0;
		break;
#ifdef __UCLIBC_HAS_IPV6__
	case AF_INET6:
		if (len != sizeof(struct in6_addr))
			return 0;
		break;
#endif /* __UCLIBC_HAS_IPV6__ */
	default:
		return 0;
	}

	inet_ntop(type, addr, ipaddr, sizeof(ipaddr));

	return(__read_etc_hosts_r(NULL, ipaddr, type, GET_HOSTS_BYADDR, 
		    result_buf, buf, buflen, result, h_errnop));
}
#endif

#ifdef L_getnameinfo

#ifndef min
# define min(x,y) (((x) > (y)) ? (y) : (x))
#endif /* min */

int getnameinfo (const struct sockaddr *sa, socklen_t addrlen, char *host,
	     socklen_t hostlen, char *serv, socklen_t servlen,
	     unsigned int flags)
{
	int serrno = errno;
	int ok = 0;
	struct hostent *h = NULL;
    char domain[256];
    
	if (flags & ~(NI_NUMERICHOST|NI_NUMERICSERV|NI_NOFQDN|NI_NAMEREQD|NI_DGRAM))
		return EAI_BADFLAGS;

	if (sa == NULL || addrlen < sizeof (sa_family_t))
		return EAI_FAMILY;

	switch (sa->sa_family) {
	case AF_LOCAL:
		break;
	case AF_INET:
		if (addrlen < sizeof (struct sockaddr_in))
			return EAI_FAMILY;
		break;
#ifdef __UCLIBC_HAS_IPV6__
	case AF_INET6:
		if (addrlen < sizeof (struct sockaddr_in6))
			return EAI_FAMILY;
		break;
#endif /* __UCLIBC_HAS_IPV6__ */
	default:
		return EAI_FAMILY;
	}

	if (host != NULL && hostlen > 0)
		switch (sa->sa_family) {
		case AF_INET:
#ifdef __UCLIBC_HAS_IPV6__
		case AF_INET6:
#endif /* __UCLIBC_HAS_IPV6__ */
			if (!(flags & NI_NUMERICHOST)) {
#ifdef __UCLIBC_HAS_IPV6__
				if (sa->sa_family == AF_INET6)
					h = gethostbyaddr ((const void *) &(((const struct sockaddr_in6 *) sa)->sin6_addr),
						sizeof(struct in6_addr), AF_INET6);
				else
#endif /* __UCLIBC_HAS_IPV6__ */
                    h = gethostbyaddr ((const void *) &(((const struct sockaddr_in *)sa)->sin_addr),
					  sizeof(struct in_addr), AF_INET);

				if (h) {
					char *c;
					if ((flags & NI_NOFQDN)
					    && (getdomainname (domain, sizeof(domain)) == 0)
					    && (c = strstr (h->h_name, domain))
					    && (c != h->h_name) && (*(--c) == '.')) {
						strncpy (host, h->h_name,
							min(hostlen, (size_t) (c - h->h_name)));
						host[min(hostlen - 1, (size_t) (c - h->h_name))] = '\0';
						ok = 1;
					} else {
						strncpy (host, h->h_name, hostlen);
						ok = 1;
					}
				 }
			}

			if (!ok) {
				if (flags & NI_NAMEREQD) {
					errno = serrno;
					return EAI_NONAME;
				} else {
					const char *c;
#ifdef __UCLIBC_HAS_IPV6__
					if (sa->sa_family == AF_INET6) {
						const struct sockaddr_in6 *sin6p;

						sin6p = (const struct sockaddr_in6 *) sa;

						c = inet_ntop (AF_INET6,
							(const void *) &sin6p->sin6_addr, host, hostlen);
#if 0
/* Does scope id need to be supported? */
						uint32_t scopeid;
						scopeid = sin6p->sin6_scope_id;
						if (scopeid != 0) {
							/* Buffer is >= IFNAMSIZ+1.  */
							char scopebuf[IFNAMSIZ + 1];
							char *scopeptr;
							int ni_numericscope = 0;
							size_t real_hostlen = __strnlen (host, hostlen);
							size_t scopelen = 0;

							scopebuf[0] = SCOPE_DELIMITER;
							scopebuf[1] = '\0';
							scopeptr = &scopebuf[1];

							if (IN6_IS_ADDR_LINKLOCAL (&sin6p->sin6_addr)
							    || IN6_IS_ADDR_MC_LINKLOCAL (&sin6p->sin6_addr)) {
								if (if_indextoname (scopeid, scopeptr) == NULL)
									++ni_numericscope;
								else
									scopelen = strlen (scopebuf);
							} else {
								++ni_numericscope;
                            }

							if (ni_numericscope)
								scopelen = 1 + snprintf (scopeptr,
									(scopebuf
									+ sizeof scopebuf
									- scopeptr),
									"%u", scopeid);

							if (real_hostlen + scopelen + 1 > hostlen)
								return EAI_SYSTEM;
							memcpy (host + real_hostlen, scopebuf, scopelen + 1);
						}
#endif
					} else
#endif /* __UCLIBC_HAS_IPV6__ */
						c = inet_ntop (AF_INET,
							(const void *) &(((const struct sockaddr_in *) sa)->sin_addr),
							host, hostlen);

					if (c == NULL) {
						errno = serrno;
						return EAI_SYSTEM;
					}
				}
				ok = 1;
			}
			break;

		case AF_LOCAL:
			if (!(flags & NI_NUMERICHOST)) {
				struct utsname utsname;

				if (!uname (&utsname)) {
					strncpy (host, utsname.nodename, hostlen);
					break;
				};
			};

			if (flags & NI_NAMEREQD) {
				errno = serrno;
				return EAI_NONAME;
			}

			strncpy (host, "localhost", hostlen);
			break;

		default:
			return EAI_FAMILY;
	}

	if (serv && (servlen > 0)) {
		switch (sa->sa_family) {
		case AF_INET:
#ifdef __UCLIBC_HAS_IPV6__
		case AF_INET6:
#endif /* __UCLIBC_HAS_IPV6__ */
			if (!(flags & NI_NUMERICSERV)) {
				struct servent *s;
				s = getservbyport (((const struct sockaddr_in *) sa)->sin_port,
				      ((flags & NI_DGRAM) ? "udp" : "tcp"));
				if (s) {
					strncpy (serv, s->s_name, servlen);
					break;
				}
			}
			snprintf (serv, servlen, "%d",
				ntohs (((const struct sockaddr_in *) sa)->sin_port));
			break;

		case AF_LOCAL:
			strncpy (serv, ((const struct sockaddr_un *) sa)->sun_path, servlen);
			break;
		}
	}
	if (host && (hostlen > 0))
		host[hostlen-1] = 0;
	if (serv && (servlen > 0))
		serv[servlen-1] = 0;
	errno = serrno;
	return 0;
}
#endif


#ifdef L_gethostbyname_r

int gethostbyname_r(const char * name,
			    struct hostent * result_buf,
			    char * buf, size_t buflen,
			    struct hostent ** result,
			    int * h_errnop)
{
	struct in_addr *in;
	struct in_addr **addr_list;
	char **alias;
	unsigned char *packet;
	struct resolv_answer a;
	int i;
	int nest = 0;
	int __nameserversXX;
	char ** __nameserverXX;

	__open_nameservers();
	*result=NULL;
	if (!name)
		return EINVAL;

	/* do /etc/hosts first */
	{
		int old_errno = errno;	/* Save the old errno and reset errno */
		__set_errno(0);			/* to check for missing /etc/hosts. */

		if ((i=__get_hosts_byname_r(name, AF_INET, result_buf,
									buf, buflen, result, h_errnop))==0)
			return i;
		switch (*h_errnop) {
			case HOST_NOT_FOUND:
			case NO_ADDRESS:
				break;
			case NETDB_INTERNAL:
				if (errno == ENOENT) {
					break;
				}
				/* else fall through */
			default:
				return i;
		}
		__set_errno(old_errno);
	}

	DPRINTF("Nothing found in /etc/hosts\n");

	*h_errnop = NETDB_INTERNAL;
	if (buflen < sizeof(*in))
		return ERANGE;
	in=(struct in_addr*)buf;
	buf+=sizeof(*in);
	buflen-=sizeof(*in);

	if (buflen < sizeof(*addr_list)*2)
		return ERANGE;
	addr_list=(struct in_addr**)buf;
	buf+=sizeof(*addr_list)*2;
	buflen-=sizeof(*addr_list)*2;

	addr_list[0] = in;
	addr_list[1] = 0;