Files
docker-deployment/build/files/addr_aliases.c

44 lines
1.2 KiB
C

#include <resolv.h>
#include <netdb.h>
#define __USE_GNU
#include <dlfcn.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
const char* getfield(char* line, int num) {
char* tmp = strdup(line);
const char* tok;
for (tok = strtok(tmp, " ");
tok && *tok;
tok = strtok(NULL, " ")) {
if (--num < 0) {
return strdup(tok);
}
}
return NULL;
}
int getaddrinfo(const char *node, const char *service, const struct addrinfo *hints, struct addrinfo **res) {
FILE* stream = fopen("/host/etc/addr_aliases", "r");
char line[1024];
while (fgets(line, 1024, stream)) {
const char* host_from = getfield(line, 0);
const char* port_from = getfield(line, 1);
const char* host_to = getfield(line, 2);
const char* port_to = getfield(line, 3);
if (strcmp(node, host_from) == 0 && strcmp(service, port_from) == 0) {
fprintf(stderr, "%s:%s => %s:%s\n", host_from, port_from, host_to, port_to);
node = host_to;
service = host_to;
}
}
if (res_init () < 0) {
return EAI_SYSTEM;
} else {
int (*f)() = dlsym (RTLD_NEXT, "getaddrinfo");
return f(node, service, hints, res);
}
}