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nslookup: full circle. Here we started IPv6 work. Use "new API"

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and thus save a few bytes.
This commit is contained in:
Denis Vlasenko 2007-01-22 22:43:05 +00:00
parent fdcd7c4237
commit 448f0241e0
3 changed files with 132 additions and 48 deletions
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39
include/libbb.h
View File

@ -278,12 +278,12 @@ extern off_t xlseek(int fd, off_t offset, int whence);
extern off_t fdlength(int fd); extern off_t fdlength(int fd);
extern int xsocket(int domain, int type, int protocol); int xsocket(int domain, int type, int protocol);
extern void xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen); void xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen);
extern void xlisten(int s, int backlog); void xlisten(int s, int backlog);
extern void xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen); void xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen);
extern int setsockopt_reuseaddr(int fd); int setsockopt_reuseaddr(int fd);
extern int setsockopt_broadcast(int fd); int setsockopt_broadcast(int fd);
/* NB: returns port in host byte order */ /* NB: returns port in host byte order */
unsigned bb_lookup_port(const char *port, const char *protocol, unsigned default_port); unsigned bb_lookup_port(const char *port, const char *protocol, unsigned default_port);
typedef struct len_and_sockaddr { typedef struct len_and_sockaddr {
@ -303,34 +303,39 @@ int xsocket_stream(len_and_sockaddr **lsap);
* numeric IP ("N.N.N.N") or numeric IPv6 address, * numeric IP ("N.N.N.N") or numeric IPv6 address,
* and can have ":PORT" suffix (for IPv6 use "[X:X:...:X]:PORT"). * and can have ":PORT" suffix (for IPv6 use "[X:X:...:X]:PORT").
* If there is no suffix, port argument is used */ * If there is no suffix, port argument is used */
extern int create_and_bind_stream_or_die(const char *bindaddr, int port); int create_and_bind_stream_or_die(const char *bindaddr, int port);
/* Create client TCP socket connected to peer:port. Peer cannot be NULL. /* Create client TCP socket connected to peer:port. Peer cannot be NULL.
* Peer can be numeric IP ("N.N.N.N"), numeric IPv6 address or hostname, * Peer can be numeric IP ("N.N.N.N"), numeric IPv6 address or hostname,
* and can have ":PORT" suffix (for IPv6 use "[X:X:...:X]:PORT"). * and can have ":PORT" suffix (for IPv6 use "[X:X:...:X]:PORT").
* If there is no suffix, port argument is used */ * If there is no suffix, port argument is used */
extern int create_and_connect_stream_or_die(const char *peer, int port); int create_and_connect_stream_or_die(const char *peer, int port);
/* Connect to peer identified by lsa */ /* Connect to peer identified by lsa */
extern int xconnect_stream(const len_and_sockaddr *lsa); int xconnect_stream(const len_and_sockaddr *lsa);
/* Return malloc'ed len_and_sockaddr with socket address of host:port /* Return malloc'ed len_and_sockaddr with socket address of host:port
* Currently will return IPv4 or IPv6 sockaddrs only * Currently will return IPv4 or IPv6 sockaddrs only
* (depending on host), but in theory nothing prevents e.g. * (depending on host), but in theory nothing prevents e.g.
* UNIX socket address being returned, IPX sockaddr etc... */ * UNIX socket address being returned, IPX sockaddr etc... */
extern len_and_sockaddr* host2sockaddr(const char *host, int port); len_and_sockaddr* host2sockaddr(const char *host, int port);
/* Assign sin[6]_port member if the socket is of corresponding type, /* Assign sin[6]_port member if the socket is of corresponding type,
* otherwise no-op. Useful for ftp. * otherwise no-op. Useful for ftp.
* NB: does NOT do htons() internally, just direct assignment. */ * NB: does NOT do htons() internally, just direct assignment. */
extern void set_nport(len_and_sockaddr *lsa, unsigned port); void set_nport(len_and_sockaddr *lsa, unsigned port);
/* Retrieve sin[6]_port or return -1 for non-INET[6] lsa's */ /* Retrieve sin[6]_port or return -1 for non-INET[6] lsa's */
extern int get_nport(len_and_sockaddr *lsa); int get_nport(len_and_sockaddr *lsa);
extern char* xmalloc_sockaddr2host(const struct sockaddr *sa, socklen_t salen); /* Reverse DNS */
extern char* xmalloc_sockaddr2dotted(const struct sockaddr *sa, socklen_t salen); char* xmalloc_sockaddr2host(const struct sockaddr *sa, socklen_t salen);
/* This one deosn't fall back to dotted IP and do not append :PORTNUM */
char* xmalloc_sockaddr2hostonly_noport(const struct sockaddr *sa, socklen_t salen);
/* inet_[ap]ton on steroids */
char* xmalloc_sockaddr2dotted(const struct sockaddr *sa, socklen_t salen);
char* xmalloc_sockaddr2dotted_noport(const struct sockaddr *sa, socklen_t salen);
// "old" (ipv4 only) API // "old" (ipv4 only) API
//void bb_lookup_host(struct sockaddr_in *s_in, const char *host); //void bb_lookup_host(struct sockaddr_in *s_in, const char *host);
//extern int xconnect_tcp_v4(struct sockaddr_in *s_addr); //int xconnect_tcp_v4(struct sockaddr_in *s_addr);
// users: traceroute.c hostname.c ifconfig.c ping.c // users: traceroute.c hostname.c ifconfig.c ping.c
extern struct hostent *xgethostbyname(const char *name); struct hostent *xgethostbyname(const char *name);
// ping6 is the only user - convert to new API // ping6 is the only user - convert to new API
extern struct hostent *xgethostbyname2(const char *name, int af); struct hostent *xgethostbyname2(const char *name, int af);
extern char *xstrdup(const char *s); extern char *xstrdup(const char *s);

22
libbb/xconnect.c
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@ -245,25 +245,36 @@ int xconnect_stream(const len_and_sockaddr *lsa)
return fd; return fd;
} }
/* We hijack this constant to mean something else */
/* It doesn't hurt because we will add this bit anyway */
#define IGNORE_PORT NI_NUMERICSERV
static char* sockaddr2str(const struct sockaddr *sa, socklen_t salen, int flags) static char* sockaddr2str(const struct sockaddr *sa, socklen_t salen, int flags)
{ {
char host[128]; char host[128];
char serv[16]; char serv[16];
int rc = getnameinfo(sa, salen, int rc = getnameinfo(sa, salen,
host, sizeof(host), host, sizeof(host),
/* can do ((flags & IGNORE_PORT) ? NULL : serv) but why bother? */
serv, sizeof(serv), serv, sizeof(serv),
/* do not resolve port# into service _name_ */ /* do not resolve port# into service _name_ */
flags | NI_NUMERICSERV flags | NI_NUMERICSERV
); );
if (rc) if (rc)
return NULL; return NULL;
if (flags & IGNORE_PORT)
return xstrdup(host);
#if ENABLE_FEATURE_IPV6 #if ENABLE_FEATURE_IPV6
if (sa->sa_family == AF_INET6) if (sa->sa_family == AF_INET6) {
if (strchr(host, ':')) /* heh, it's not a resolved hostname */
return xasprintf("[%s]:%s", host, serv); return xasprintf("[%s]:%s", host, serv);
/*return xasprintf("%s:%s", host, serv);*/
/* - fall through instead */
}
#endif #endif
/* For now we don't support anything else, so it has to be INET */ /* For now we don't support anything else, so it has to be INET */
/*if (sa->sa_family == AF_INET)*/ /*if (sa->sa_family == AF_INET)*/
return xasprintf("%s:%s", host, serv); return xasprintf("%s:%s", host, serv);
/*return xstrdup(host);*/
} }
char* xmalloc_sockaddr2host(const struct sockaddr *sa, socklen_t salen) char* xmalloc_sockaddr2host(const struct sockaddr *sa, socklen_t salen)
@ -271,7 +282,16 @@ char* xmalloc_sockaddr2host(const struct sockaddr *sa, socklen_t salen)
return sockaddr2str(sa, salen, 0); return sockaddr2str(sa, salen, 0);
} }
char* xmalloc_sockaddr2hostonly_noport(const struct sockaddr *sa, socklen_t salen)
{
return sockaddr2str(sa, salen, NI_NAMEREQD | IGNORE_PORT);
}
char* xmalloc_sockaddr2dotted(const struct sockaddr *sa, socklen_t salen) char* xmalloc_sockaddr2dotted(const struct sockaddr *sa, socklen_t salen)
{ {
return sockaddr2str(sa, salen, NI_NUMERICHOST); return sockaddr2str(sa, salen, NI_NUMERICHOST);
} }
char* xmalloc_sockaddr2dotted_noport(const struct sockaddr *sa, socklen_t salen)
{
return sockaddr2str(sa, salen, NI_NUMERICHOST | IGNORE_PORT);
}

111
networking/nslookup.c
View File

@ -47,7 +47,7 @@
* ns3.kernel.org internet address = 204.152.191.36 * ns3.kernel.org internet address = 204.152.191.36
*/ */
static int sockaddr_to_dotted(struct sockaddr *saddr, char *buf, int buflen) /*static int sockaddr_to_dotted(struct sockaddr *saddr, char *buf, int buflen)
{ {
if (buflen <= 0) return -1; if (buflen <= 0) return -1;
buf[0] = '\0'; buf[0] = '\0';
@ -61,9 +61,11 @@ static int sockaddr_to_dotted(struct sockaddr *saddr, char *buf, int buflen)
} }
return -1; return -1;
} }
*/
static int print_host(const char *hostname, const char *header) static int print_host(const char *hostname, const char *header)
{ {
#if 0
char str[128]; /* IPv6 address will fit, hostnames hopefully too */ char str[128]; /* IPv6 address will fit, hostnames hopefully too */
struct addrinfo *result = NULL; struct addrinfo *result = NULL;
int rc; int rc;
@ -76,6 +78,7 @@ static int print_host(const char *hostname, const char *header)
hint.ai_socktype = SOCK_STREAM; hint.ai_socktype = SOCK_STREAM;
// hint.ai_flags = AI_CANONNAME; // hint.ai_flags = AI_CANONNAME;
rc = getaddrinfo(hostname, NULL /*service*/, &hint, &result); rc = getaddrinfo(hostname, NULL /*service*/, &hint, &result);
if (!rc) { if (!rc) {
struct addrinfo *cur = result; struct addrinfo *cur = result;
// printf("%s\n", cur->ai_canonname); ? // printf("%s\n", cur->ai_canonname); ?
@ -93,6 +96,75 @@ static int print_host(const char *hostname, const char *header)
} }
freeaddrinfo(result); freeaddrinfo(result);
return (rc != 0); return (rc != 0);
#else
/* We can't use host2sockaddr() - we want to get ALL addresses,
* not just one */
struct addrinfo *result = NULL;
int rc;
struct addrinfo hint;
memset(&hint, 0 , sizeof(hint));
/* hint.ai_family = AF_UNSPEC; - zero anyway */
/* Needed. Or else we will get each address thrice (or more)
* for each possible socket type (tcp,udp,raw...): */
hint.ai_socktype = SOCK_STREAM;
// hint.ai_flags = AI_CANONNAME;
rc = getaddrinfo(hostname, NULL /*service*/, &hint, &result);
if (!rc) {
struct addrinfo *cur = result;
unsigned cnt = 0;
printf("%-10s %s\n", header, hostname);
// printf("%s\n", cur->ai_canonname); ?
while (cur) {
char *dotted, *revhost;
dotted = xmalloc_sockaddr2dotted_noport(cur->ai_addr, cur->ai_addrlen);
revhost = xmalloc_sockaddr2hostonly_noport(cur->ai_addr, cur->ai_addrlen);
printf("Address %u: %s%c", ++cnt, dotted, revhost ? ' ' : '\n');
if (revhost) {
puts(revhost);
if (ENABLE_FEATURE_CLEAN_UP)
free(revhost);
}
if (ENABLE_FEATURE_CLEAN_UP)
free(dotted);
cur = cur->ai_next;
}
} else {
#if ENABLE_VERBOSE_RESOLUTION_ERRORS
bb_error_msg("getaddrinfo('%s') failed: %s", hostname, gai_strerror(rc));
#else
bb_error_msg("can't resolve '%s'", hostname);
#endif
}
if (ENABLE_FEATURE_CLEAN_UP)
freeaddrinfo(result);
return (rc != 0);
#endif
}
/* lookup the default nameserver and display it */
static void server_print(void)
{
char *server;
server = xmalloc_sockaddr2dotted_noport((struct sockaddr*)&_res.nsaddr_list[0],
sizeof(struct sockaddr_in));
/* I honestly don't know what to do if DNS server has _IPv6 address_.
* Probably it is listed in
* _res._u._ext_.nsaddrs[MAXNS] (of type "struct sockaddr_in6*" each)
* but how to find out whether resolver uses
* _res.nsaddr_list[] or _res._u._ext_.nsaddrs[], or both?
* Looks like classic design from hell, BIND-grade. Hard to surpass. */
print_host(server, "Server:");
if (ENABLE_FEATURE_CLEAN_UP)
free(server);
puts("");
} }
@ -109,40 +181,27 @@ static void set_default_dns(char *server)
} }
/* lookup the default nameserver and display it */
static void server_print(void)
{
char str[INET6_ADDRSTRLEN];
sockaddr_to_dotted((struct sockaddr*)&_res.nsaddr_list[0], str, sizeof(str));
print_host(str, "Server:");
puts("");
}
int nslookup_main(int argc, char **argv) int nslookup_main(int argc, char **argv)
{ {
/* /* We allow 1 or 2 arguments.
* initialize DNS structure _res used in printing the default
* name server and in the explicit name server option feature.
*/
res_init();
/*
* We allow 1 or 2 arguments.
* The first is the name to be looked up and the second is an * The first is the name to be looked up and the second is an
* optional DNS server with which to do the lookup. * optional DNS server with which to do the lookup.
* More than 3 arguments is an error to follow the pattern of the * More than 3 arguments is an error to follow the pattern of the
* standard nslookup * standard nslookup */
*/
if (argc < 2 || *argv[1] == '-' || argc > 3) if (argc < 2 || *argv[1] == '-' || argc > 3)
bb_show_usage(); bb_show_usage();
else if(argc == 3)
/* initialize DNS structure _res used in printing the default
* name server and in the explicit name server option feature. */
res_init();
/* rfc2133 says this enables IPv6 lookups */
/* (but it also says "may be enabled in /etc/resolv.conf|) */
/*_res.options |= RES_USE_INET6;*/
if(argc == 3)
set_default_dns(argv[2]); set_default_dns(argv[2]);
server_print(); server_print();
return print_host(argv[1], "Name: "); return print_host(argv[1], "Name:");
} }