nslookup: full circle. Here we started IPv6 work. Use "new API"
and thus save a few bytes.
This commit is contained in:
Denis Vlasenko
parent
fdcd7c4237
commit
448f0241e0
@ -278,12 +278,12 @@ extern off_t xlseek(int fd, off_t offset, int whence);
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extern off_t fdlength(int fd);
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extern int xsocket(int domain, int type, int protocol);
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extern void xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen);
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extern void xlisten(int s, int backlog);
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extern void xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen);
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extern int setsockopt_reuseaddr(int fd);
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extern int setsockopt_broadcast(int fd);
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int xsocket(int domain, int type, int protocol);
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void xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen);
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void xlisten(int s, int backlog);
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void xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen);
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int setsockopt_reuseaddr(int fd);
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int setsockopt_broadcast(int fd);
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/* NB: returns port in host byte order */
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unsigned bb_lookup_port(const char *port, const char *protocol, unsigned default_port);
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typedef struct len_and_sockaddr {
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@ -303,34 +303,39 @@ int xsocket_stream(len_and_sockaddr **lsap);
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* numeric IP ("N.N.N.N") or numeric IPv6 address,
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* and can have ":PORT" suffix (for IPv6 use "[X:X:...:X]:PORT").
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* If there is no suffix, port argument is used */
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extern int create_and_bind_stream_or_die(const char *bindaddr, int port);
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int create_and_bind_stream_or_die(const char *bindaddr, int port);
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/* Create client TCP socket connected to peer:port. Peer cannot be NULL.
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* Peer can be numeric IP ("N.N.N.N"), numeric IPv6 address or hostname,
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* and can have ":PORT" suffix (for IPv6 use "[X:X:...:X]:PORT").
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* If there is no suffix, port argument is used */
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extern int create_and_connect_stream_or_die(const char *peer, int port);
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int create_and_connect_stream_or_die(const char *peer, int port);
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/* Connect to peer identified by lsa */
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extern int xconnect_stream(const len_and_sockaddr *lsa);
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int xconnect_stream(const len_and_sockaddr *lsa);
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/* Return malloc'ed len_and_sockaddr with socket address of host:port
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* Currently will return IPv4 or IPv6 sockaddrs only
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* (depending on host), but in theory nothing prevents e.g.
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* UNIX socket address being returned, IPX sockaddr etc... */
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extern len_and_sockaddr* host2sockaddr(const char *host, int port);
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len_and_sockaddr* host2sockaddr(const char *host, int port);
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/* Assign sin[6]_port member if the socket is of corresponding type,
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* otherwise no-op. Useful for ftp.
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* NB: does NOT do htons() internally, just direct assignment. */
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extern void set_nport(len_and_sockaddr *lsa, unsigned port);
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void set_nport(len_and_sockaddr *lsa, unsigned port);
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/* Retrieve sin[6]_port or return -1 for non-INET[6] lsa's */
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extern int get_nport(len_and_sockaddr *lsa);
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extern char* xmalloc_sockaddr2host(const struct sockaddr *sa, socklen_t salen);
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extern char* xmalloc_sockaddr2dotted(const struct sockaddr *sa, socklen_t salen);
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int get_nport(len_and_sockaddr *lsa);
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/* Reverse DNS */
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char* xmalloc_sockaddr2host(const struct sockaddr *sa, socklen_t salen);
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/* This one deosn't fall back to dotted IP and do not append :PORTNUM */
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char* xmalloc_sockaddr2hostonly_noport(const struct sockaddr *sa, socklen_t salen);
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/* inet_[ap]ton on steroids */
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char* xmalloc_sockaddr2dotted(const struct sockaddr *sa, socklen_t salen);
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char* xmalloc_sockaddr2dotted_noport(const struct sockaddr *sa, socklen_t salen);
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// "old" (ipv4 only) API
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//void bb_lookup_host(struct sockaddr_in *s_in, const char *host);
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//extern int xconnect_tcp_v4(struct sockaddr_in *s_addr);
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//int xconnect_tcp_v4(struct sockaddr_in *s_addr);
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// users: traceroute.c hostname.c ifconfig.c ping.c
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extern struct hostent *xgethostbyname(const char *name);
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struct hostent *xgethostbyname(const char *name);
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// ping6 is the only user - convert to new API
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extern struct hostent *xgethostbyname2(const char *name, int af);
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struct hostent *xgethostbyname2(const char *name, int af);
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extern char *xstrdup(const char *s);
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@ -245,25 +245,36 @@ int xconnect_stream(const len_and_sockaddr *lsa)
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return fd;
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}
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/* We hijack this constant to mean something else */
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/* It doesn't hurt because we will add this bit anyway */
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#define IGNORE_PORT NI_NUMERICSERV
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static char* sockaddr2str(const struct sockaddr *sa, socklen_t salen, int flags)
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{
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char host[128];
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char serv[16];
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int rc = getnameinfo(sa, salen,
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host, sizeof(host),
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/* can do ((flags & IGNORE_PORT) ? NULL : serv) but why bother? */
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serv, sizeof(serv),
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/* do not resolve port# into service _name_ */
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flags | NI_NUMERICSERV
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);
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if (rc)
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return NULL;
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if (flags & IGNORE_PORT)
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return xstrdup(host);
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#if ENABLE_FEATURE_IPV6
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if (sa->sa_family == AF_INET6)
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return xasprintf("[%s]:%s", host, serv);
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if (sa->sa_family == AF_INET6) {
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if (strchr(host, ':')) /* heh, it's not a resolved hostname */
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return xasprintf("[%s]:%s", host, serv);
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/*return xasprintf("%s:%s", host, serv);*/
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/* - fall through instead */
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}
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#endif
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/* For now we don't support anything else, so it has to be INET */
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/*if (sa->sa_family == AF_INET)*/
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return xasprintf("%s:%s", host, serv);
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/*return xstrdup(host);*/
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}
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char* xmalloc_sockaddr2host(const struct sockaddr *sa, socklen_t salen)
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@ -271,7 +282,16 @@ char* xmalloc_sockaddr2host(const struct sockaddr *sa, socklen_t salen)
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return sockaddr2str(sa, salen, 0);
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}
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char* xmalloc_sockaddr2hostonly_noport(const struct sockaddr *sa, socklen_t salen)
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{
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return sockaddr2str(sa, salen, NI_NAMEREQD | IGNORE_PORT);
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}
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char* xmalloc_sockaddr2dotted(const struct sockaddr *sa, socklen_t salen)
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{
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return sockaddr2str(sa, salen, NI_NUMERICHOST);
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}
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char* xmalloc_sockaddr2dotted_noport(const struct sockaddr *sa, socklen_t salen)
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{
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return sockaddr2str(sa, salen, NI_NUMERICHOST | IGNORE_PORT);
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}
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@ -47,7 +47,7 @@
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* ns3.kernel.org internet address = 204.152.191.36
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*/
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static int sockaddr_to_dotted(struct sockaddr *saddr, char *buf, int buflen)
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/*static int sockaddr_to_dotted(struct sockaddr *saddr, char *buf, int buflen)
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{
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if (buflen <= 0) return -1;
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buf[0] = '\0';
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@ -61,9 +61,11 @@ static int sockaddr_to_dotted(struct sockaddr *saddr, char *buf, int buflen)
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}
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return -1;
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}
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*/
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static int print_host(const char *hostname, const char *header)
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{
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#if 0
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char str[128]; /* IPv6 address will fit, hostnames hopefully too */
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struct addrinfo *result = NULL;
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int rc;
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@ -76,6 +78,7 @@ static int print_host(const char *hostname, const char *header)
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hint.ai_socktype = SOCK_STREAM;
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// hint.ai_flags = AI_CANONNAME;
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rc = getaddrinfo(hostname, NULL /*service*/, &hint, &result);
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if (!rc) {
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struct addrinfo *cur = result;
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// printf("%s\n", cur->ai_canonname); ?
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@ -93,6 +96,75 @@ static int print_host(const char *hostname, const char *header)
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}
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freeaddrinfo(result);
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return (rc != 0);
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#else
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/* We can't use host2sockaddr() - we want to get ALL addresses,
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* not just one */
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struct addrinfo *result = NULL;
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int rc;
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struct addrinfo hint;
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memset(&hint, 0 , sizeof(hint));
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/* hint.ai_family = AF_UNSPEC; - zero anyway */
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/* Needed. Or else we will get each address thrice (or more)
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* for each possible socket type (tcp,udp,raw...): */
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hint.ai_socktype = SOCK_STREAM;
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// hint.ai_flags = AI_CANONNAME;
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rc = getaddrinfo(hostname, NULL /*service*/, &hint, &result);
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if (!rc) {
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struct addrinfo *cur = result;
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unsigned cnt = 0;
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printf("%-10s %s\n", header, hostname);
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// printf("%s\n", cur->ai_canonname); ?
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while (cur) {
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char *dotted, *revhost;
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dotted = xmalloc_sockaddr2dotted_noport(cur->ai_addr, cur->ai_addrlen);
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revhost = xmalloc_sockaddr2hostonly_noport(cur->ai_addr, cur->ai_addrlen);
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printf("Address %u: %s%c", ++cnt, dotted, revhost ? ' ' : '\n');
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if (revhost) {
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puts(revhost);
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if (ENABLE_FEATURE_CLEAN_UP)
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free(revhost);
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}
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if (ENABLE_FEATURE_CLEAN_UP)
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free(dotted);
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cur = cur->ai_next;
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}
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} else {
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#if ENABLE_VERBOSE_RESOLUTION_ERRORS
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bb_error_msg("getaddrinfo('%s') failed: %s", hostname, gai_strerror(rc));
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#else
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bb_error_msg("can't resolve '%s'", hostname);
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#endif
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}
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if (ENABLE_FEATURE_CLEAN_UP)
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freeaddrinfo(result);
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return (rc != 0);
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#endif
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}
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/* lookup the default nameserver and display it */
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static void server_print(void)
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{
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char *server;
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server = xmalloc_sockaddr2dotted_noport((struct sockaddr*)&_res.nsaddr_list[0],
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sizeof(struct sockaddr_in));
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/* I honestly don't know what to do if DNS server has _IPv6 address_.
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* Probably it is listed in
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* _res._u._ext_.nsaddrs[MAXNS] (of type "struct sockaddr_in6*" each)
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* but how to find out whether resolver uses
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* _res.nsaddr_list[] or _res._u._ext_.nsaddrs[], or both?
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* Looks like classic design from hell, BIND-grade. Hard to surpass. */
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print_host(server, "Server:");
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if (ENABLE_FEATURE_CLEAN_UP)
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free(server);
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puts("");
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}
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@ -109,40 +181,27 @@ static void set_default_dns(char *server)
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}
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/* lookup the default nameserver and display it */
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static void server_print(void)
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{
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char str[INET6_ADDRSTRLEN];
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sockaddr_to_dotted((struct sockaddr*)&_res.nsaddr_list[0], str, sizeof(str));
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print_host(str, "Server:");
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puts("");
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}
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int nslookup_main(int argc, char **argv)
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{
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/*
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* initialize DNS structure _res used in printing the default
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* name server and in the explicit name server option feature.
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*/
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res_init();
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/*
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* We allow 1 or 2 arguments.
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* The first is the name to be looked up and the second is an
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* optional DNS server with which to do the lookup.
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* More than 3 arguments is an error to follow the pattern of the
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* standard nslookup
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*/
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/* We allow 1 or 2 arguments.
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* The first is the name to be looked up and the second is an
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* optional DNS server with which to do the lookup.
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* More than 3 arguments is an error to follow the pattern of the
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* standard nslookup */
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if (argc < 2 || *argv[1] == '-' || argc > 3)
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bb_show_usage();
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else if(argc == 3)
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/* initialize DNS structure _res used in printing the default
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* name server and in the explicit name server option feature. */
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res_init();
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/* rfc2133 says this enables IPv6 lookups */
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/* (but it also says "may be enabled in /etc/resolv.conf|) */
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/*_res.options |= RES_USE_INET6;*/
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if(argc == 3)
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set_default_dns(argv[2]);
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server_print();
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return print_host(argv[1], "Name: ");
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return print_host(argv[1], "Name:");
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}
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