tinc/lib/fake-getaddrinfo.c
2019-08-26 13:44:36 +02:00

105 lines
2.3 KiB
C

/*
* fake library for ssh
*
* This file includes getaddrinfo(), freeaddrinfo() and gai_strerror().
* These funtions are defined in rfc2133.
*
* But these functions are not implemented correctly. The minimum subset
* is implemented for ssh use only. For exapmle, this routine assumes
* that ai_family is AF_INET. Don't use it for another purpose.
*/
#include "system.h"
#include "ipv4.h"
#include "ipv6.h"
#include "fake-getaddrinfo.h"
#include "xalloc.h"
#ifndef HAVE_GAI_STRERROR
char *gai_strerror(int ecode)
{
switch (ecode) {
case EAI_NODATA:
return "No address associated with hostname";
case EAI_MEMORY:
return "Memory allocation failure";
case EAI_FAMILY:
return "Address family not supported";
default:
return "Unknown error";
}
}
#endif /* !HAVE_GAI_STRERROR */
#ifndef HAVE_FREEADDRINFO
void freeaddrinfo(struct addrinfo *ai)
{
struct addrinfo *next;
while(ai) {
next = ai->ai_next;
free(ai);
ai = next;
}
}
#endif /* !HAVE_FREEADDRINFO */
#ifndef HAVE_GETADDRINFO
static struct addrinfo *malloc_ai(uint16_t port, uint32_t addr)
{
struct addrinfo *ai;
ai = xmalloc_and_zero(sizeof(struct addrinfo) + sizeof(struct sockaddr_in));
ai->ai_addr = (struct sockaddr *)(ai + 1);
ai->ai_addrlen = sizeof(struct sockaddr_in);
ai->ai_addr->sa_family = ai->ai_family = AF_INET;
((struct sockaddr_in *)(ai)->ai_addr)->sin_port = port;
((struct sockaddr_in *)(ai)->ai_addr)->sin_addr.s_addr = addr;
return ai;
}
int getaddrinfo(const char *hostname, const char *servname, const struct addrinfo *hints, struct addrinfo **res)
{
struct addrinfo *prev = NULL;
struct hostent *hp;
struct in_addr in = {0};
int i;
uint16_t port = 0;
if(hints && hints->ai_family != AF_INET && hints->ai_family != AF_UNSPEC)
return EAI_FAMILY;
if (servname)
port = htons(atoi(servname));
if (hints && hints->ai_flags & AI_PASSIVE) {
*res = malloc_ai(port, htonl(0x00000000));
return 0;
}
if (!hostname) {
*res = malloc_ai(port, htonl(0x7f000001));
return 0;
}
hp = gethostbyname(hostname);
if(!hp || !hp->h_addr_list || !hp->h_addr_list[0])
return EAI_NODATA;
for (i = 0; hp->h_addr_list[i]; i++) {
*res = malloc_ai(port, ((struct in_addr *)hp->h_addr_list[i])->s_addr);
if(prev)
prev->ai_next = *res;
prev = *res;
}
return 0;
}
#endif /* !HAVE_GETADDRINFO */