| #define _GNU_SOURCE |
| |
| #include <sys/socket.h> |
| #include <netdb.h> |
| #include <string.h> |
| #include <netinet/in.h> |
| #include <errno.h> |
| #include <inttypes.h> |
| |
| int gethostbyname2_r(const char *name, int af, |
| struct hostent *h, char *buf, size_t buflen, |
| struct hostent **res, int *err) |
| { |
| struct addrinfo hint = { |
| .ai_family = af==AF_INET6 ? af : AF_INET, |
| .ai_flags = AI_CANONNAME |
| }; |
| struct addrinfo *ai, *p; |
| int i; |
| size_t need; |
| const char *canon; |
| |
| af = hint.ai_family; |
| |
| /* Align buffer */ |
| i = (uintptr_t)buf & sizeof(char *)-1; |
| if (i) { |
| if (buflen < sizeof(char *)-i) return ERANGE; |
| buf += sizeof(char *)-i; |
| buflen -= sizeof(char *)-i; |
| } |
| |
| getaddrinfo(name, 0, &hint, &ai); |
| switch (getaddrinfo(name, 0, &hint, &ai)) { |
| case EAI_NONAME: |
| *err = HOST_NOT_FOUND; |
| return errno; |
| case EAI_AGAIN: |
| *err = TRY_AGAIN; |
| return errno; |
| default: |
| case EAI_MEMORY: |
| case EAI_SYSTEM: |
| case EAI_FAIL: |
| *err = NO_RECOVERY; |
| return errno; |
| case 0: |
| break; |
| } |
| |
| h->h_addrtype = af; |
| h->h_length = af==AF_INET6 ? 16 : 4; |
| |
| canon = ai->ai_canonname ? ai->ai_canonname : name; |
| need = 4*sizeof(char *); |
| for (i=0, p=ai; p; i++, p=p->ai_next) |
| need += sizeof(char *) + h->h_length; |
| need += strlen(name)+1; |
| need += strlen(canon)+1; |
| |
| if (need > buflen) { |
| freeaddrinfo(ai); |
| return ERANGE; |
| } |
| |
| h->h_aliases = (void *)buf; |
| buf += 3*sizeof(char *); |
| h->h_addr_list = (void *)buf; |
| buf += (i+1)*sizeof(char *); |
| |
| h->h_name = h->h_aliases[0] = buf; |
| strcpy(h->h_name, canon); |
| buf += strlen(h->h_name)+1; |
| |
| if (strcmp(h->h_name, name)) { |
| h->h_aliases[1] = buf; |
| strcpy(h->h_aliases[1], name); |
| buf += strlen(h->h_aliases[1])+1; |
| } else h->h_aliases[1] = 0; |
| |
| h->h_aliases[2] = 0; |
| |
| for (i=0, p=ai; p; i++, p=p->ai_next) { |
| h->h_addr_list[i] = (void *)buf; |
| buf += h->h_length; |
| memcpy(h->h_addr_list[i], |
| &((struct sockaddr_in *)p->ai_addr)->sin_addr, |
| h->h_length); |
| } |
| h->h_addr_list[i] = 0; |
| |
| *res = h; |
| freeaddrinfo(ai); |
| return 0; |
| } |