| #include <netdb.h> |
| #include <limits.h> |
| #include <string.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| #include <net/if.h> |
| #include <ctype.h> |
| #include <resolv.h> |
| #include "lookup.h" |
| #include "stdio_impl.h" |
| |
| #define PTR_MAX (64 + sizeof ".in-addr.arpa") |
| #define RR_PTR 12 |
| |
| static char *itoa(char *p, unsigned x) { |
| p += 3*sizeof(int); |
| *--p = 0; |
| do { |
| *--p = '0' + x % 10; |
| x /= 10; |
| } while (x); |
| return p; |
| } |
| |
| static void mkptr4(char *s, const unsigned char *ip) |
| { |
| sprintf(s, "%d.%d.%d.%d.in-addr.arpa", |
| ip[3], ip[2], ip[1], ip[0]); |
| } |
| |
| static void mkptr6(char *s, const unsigned char *ip) |
| { |
| static const char xdigits[] = "0123456789abcdef"; |
| int i; |
| for (i=15; i>=0; i--) { |
| *s++ = xdigits[ip[i]&15]; *s++ = '.'; |
| *s++ = xdigits[ip[i]>>4]; *s++ = '.'; |
| } |
| strcpy(s, "ip6.arpa"); |
| } |
| |
| static void reverse_hosts(char *buf, const unsigned char *a, unsigned scopeid, int family) |
| { |
| char line[512], *p, *z; |
| unsigned char _buf[1032], atmp[16]; |
| struct address iplit; |
| FILE _f, *f = __fopen_rb_ca("/etc/hosts", &_f, _buf, sizeof _buf); |
| if (!f) return; |
| if (family == AF_INET) { |
| memcpy(atmp+12, a, 4); |
| memcpy(atmp, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12); |
| a = atmp; |
| } |
| while (fgets(line, sizeof line, f)) { |
| if ((p=strchr(line, '#'))) *p++='\n', *p=0; |
| |
| for (p=line; *p && !isspace(*p); p++); |
| *p++ = 0; |
| if (__lookup_ipliteral(&iplit, line, AF_UNSPEC)<=0) |
| continue; |
| |
| if (iplit.family == AF_INET) { |
| memcpy(iplit.addr+12, iplit.addr, 4); |
| memcpy(iplit.addr, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12); |
| iplit.scopeid = 0; |
| } |
| |
| if (memcmp(a, iplit.addr, 16) || iplit.scopeid != scopeid) |
| continue; |
| |
| for (; *p && isspace(*p); p++); |
| for (z=p; *z && !isspace(*z); z++); |
| *z = 0; |
| if (z-p < 256) { |
| memcpy(buf, p, z-p+1); |
| break; |
| } |
| } |
| __fclose_ca(f); |
| } |
| |
| static void reverse_services(char *buf, int port, int dgram) |
| { |
| unsigned long svport; |
| char line[128], *p, *z; |
| unsigned char _buf[1032]; |
| FILE _f, *f = __fopen_rb_ca("/etc/services", &_f, _buf, sizeof _buf); |
| if (!f) return; |
| while (fgets(line, sizeof line, f)) { |
| if ((p=strchr(line, '#'))) *p++='\n', *p=0; |
| |
| for (p=line; *p && !isspace(*p); p++); |
| if (!*p) continue; |
| *p++ = 0; |
| svport = strtoul(p, &z, 10); |
| |
| if (svport != port || z==p) continue; |
| if (dgram && strncmp(z, "/udp", 4)) continue; |
| if (!dgram && strncmp(z, "/tcp", 4)) continue; |
| if (p-line > 32) continue; |
| |
| memcpy(buf, line, p-line); |
| break; |
| } |
| __fclose_ca(f); |
| } |
| |
| static int dns_parse_callback(void *c, int rr, const void *data, int len, const void *packet) |
| { |
| if (rr != RR_PTR) return 0; |
| if (__dn_expand(packet, (const unsigned char *)packet + 512, |
| data, c, 256) <= 0) |
| *(char *)c = 0; |
| return 0; |
| |
| } |
| |
| int getnameinfo(const struct sockaddr *restrict sa, socklen_t sl, |
| char *restrict node, socklen_t nodelen, |
| char *restrict serv, socklen_t servlen, |
| int flags) |
| { |
| char ptr[PTR_MAX]; |
| char buf[256], num[3*sizeof(int)+1]; |
| int af = sa->sa_family; |
| unsigned char *a; |
| unsigned scopeid; |
| |
| switch (af) { |
| case AF_INET: |
| a = (void *)&((struct sockaddr_in *)sa)->sin_addr; |
| if (sl < sizeof(struct sockaddr_in)) return EAI_FAMILY; |
| mkptr4(ptr, a); |
| scopeid = 0; |
| break; |
| case AF_INET6: |
| a = (void *)&((struct sockaddr_in6 *)sa)->sin6_addr; |
| if (sl < sizeof(struct sockaddr_in6)) return EAI_FAMILY; |
| if (memcmp(a, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12)) |
| mkptr6(ptr, a); |
| else |
| mkptr4(ptr, a+12); |
| scopeid = ((struct sockaddr_in6 *)sa)->sin6_scope_id; |
| break; |
| default: |
| return EAI_FAMILY; |
| } |
| |
| if (node && nodelen) { |
| buf[0] = 0; |
| if (!(flags & NI_NUMERICHOST)) { |
| reverse_hosts(buf, a, scopeid, af); |
| } |
| if (!*buf && !(flags & NI_NUMERICHOST)) { |
| unsigned char query[18+PTR_MAX], reply[512]; |
| int qlen = __res_mkquery(0, ptr, 1, RR_PTR, |
| 0, 0, 0, query, sizeof query); |
| query[3] = 0; /* don't need AD flag */ |
| int rlen = __res_send(query, qlen, reply, sizeof reply); |
| buf[0] = 0; |
| if (rlen > 0) |
| __dns_parse(reply, rlen, dns_parse_callback, buf); |
| } |
| if (!*buf) { |
| if (flags & NI_NAMEREQD) return EAI_NONAME; |
| inet_ntop(af, a, buf, sizeof buf); |
| if (scopeid) { |
| char *p = 0, tmp[IF_NAMESIZE+1]; |
| if (!(flags & NI_NUMERICSCOPE) && |
| (IN6_IS_ADDR_LINKLOCAL(a) || |
| IN6_IS_ADDR_MC_LINKLOCAL(a))) |
| p = if_indextoname(scopeid, tmp+1); |
| if (!p) |
| p = itoa(num, scopeid); |
| *--p = '%'; |
| strcat(buf, p); |
| } |
| } |
| if (strlen(buf) >= nodelen) return EAI_OVERFLOW; |
| strcpy(node, buf); |
| } |
| |
| if (serv && servlen) { |
| char *p = buf; |
| int port = ntohs(((struct sockaddr_in *)sa)->sin_port); |
| buf[0] = 0; |
| if (!(flags & NI_NUMERICSERV)) |
| reverse_services(buf, port, flags & NI_DGRAM); |
| if (!*p) |
| p = itoa(num, port); |
| if (strlen(p) >= servlen) |
| return EAI_OVERFLOW; |
| strcpy(serv, p); |
| } |
| |
| return 0; |
| } |