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#include <AK/AKString.h>
#include <AK/Assertions.h>
#include <AK/ScopeGuard.h>
#include <Kernel/Net/IPv4.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
extern "C" {
static hostent __gethostbyname_buffer;
static char __gethostbyname_name_buffer[512];
static in_addr_t __gethostbyname_address;
static in_addr_t* __gethostbyname_address_list_buffer[2];
static hostent __gethostbyaddr_buffer;
static char __gethostbyaddr_name_buffer[512];
static in_addr_t* __gethostbyaddr_address_list_buffer[2];
static int connect_to_lookup_server()
{
int fd = socket(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0);
if (fd < 0) {
perror("socket");
return -1;
}
sockaddr_un address;
address.sun_family = AF_LOCAL;
strcpy(address.sun_path, "/tmp/.LookupServer-socket");
int retries = 3;
int rc = 0;
while (retries) {
rc = connect(fd, (const sockaddr*)&address, sizeof(address));
if (rc == 0)
break;
--retries;
sleep(1);
}
if (rc < 0) {
close(fd);
return -1;
}
return fd;
}
hostent* gethostbyname(const char* name)
{
unsigned a;
unsigned b;
unsigned c;
unsigned d;
int count = sscanf(name, "%u.%u.%u.%u", &a, &b, &c, &d);
if (count == 4 && a < 256 && b < 256 && c < 256 && d < 256) {
sprintf(__gethostbyname_name_buffer, "%u.%u.%u.%u", a, b, c, d);
__gethostbyname_buffer.h_name = __gethostbyname_name_buffer;
__gethostbyname_buffer.h_aliases = nullptr;
__gethostbyname_buffer.h_addrtype = AF_INET;
new (&__gethostbyname_address) IPv4Address(a, b, c, d);
__gethostbyname_address_list_buffer[0] = &__gethostbyname_address;
__gethostbyname_address_list_buffer[1] = nullptr;
__gethostbyname_buffer.h_addr_list = (char**)__gethostbyname_address_list_buffer;
__gethostbyname_buffer.h_length = 4;
return &__gethostbyname_buffer;
}
int fd = connect_to_lookup_server();
if (fd < 0)
return nullptr;
auto close_fd_on_exit = ScopeGuard([fd] {
dbgprintf("closing fd\n");
close(fd);
});
auto line = String::format("L%s\n", name);
int nsent = write(fd, line.characters(), line.length());
if (nsent < 0) {
perror("write");
return nullptr;
}
ASSERT(nsent == line.length());
char buffer[1024];
int nrecv = read(fd, buffer, sizeof(buffer) - 1);
if (nrecv < 0) {
perror("recv");
return nullptr;
}
buffer[nrecv] = '\0';
if (!memcmp(buffer, "Not found.", sizeof("Not found.") - 1))
return nullptr;
int rc = inet_pton(AF_INET, buffer, &__gethostbyname_address);
if (rc <= 0)
return nullptr;
strncpy(__gethostbyname_name_buffer, name, strlen(name));
__gethostbyname_buffer.h_name = __gethostbyname_name_buffer;
__gethostbyname_buffer.h_aliases = nullptr;
__gethostbyname_buffer.h_addrtype = AF_INET;
__gethostbyname_address_list_buffer[0] = &__gethostbyname_address;
__gethostbyname_address_list_buffer[1] = nullptr;
__gethostbyname_buffer.h_addr_list = (char**)__gethostbyname_address_list_buffer;
__gethostbyname_buffer.h_length = 4;
return &__gethostbyname_buffer;
}
hostent* gethostbyaddr(const void* addr, socklen_t addr_size, int type)
{
if (type != AF_INET) {
errno = EAFNOSUPPORT;
return nullptr;
}
if (addr_size < sizeof(in_addr)) {
errno = EINVAL;
return nullptr;
}
int fd = connect_to_lookup_server();
if (fd < 0)
return nullptr;
auto close_fd_on_exit = ScopeGuard([fd] {
close(fd);
});
IPv4Address ipv4_address((const byte*)&((const in_addr*)addr)->s_addr);
auto line = String::format("R%d.%d.%d.%d.in-addr.arpa\n",
ipv4_address[3],
ipv4_address[2],
ipv4_address[1],
ipv4_address[0]);
int nsent = write(fd, line.characters(), line.length());
if (nsent < 0) {
perror("write");
return nullptr;
}
ASSERT(nsent == line.length());
char buffer[1024];
int nrecv = read(fd, buffer, sizeof(buffer) - 1);
if (nrecv < 0) {
perror("recv");
return nullptr;
}
if (nrecv > 1) {
// Strip newline.
buffer[nrecv - 1] = '\0';
}
buffer[nrecv] = '\0';
if (!memcmp(buffer, "Not found.", sizeof("Not found.") - 1))
return nullptr;
strncpy(__gethostbyaddr_name_buffer, buffer, max(sizeof(__gethostbyaddr_name_buffer), (size_t)nrecv));
__gethostbyaddr_buffer.h_name = __gethostbyaddr_name_buffer;
__gethostbyaddr_buffer.h_aliases = nullptr;
__gethostbyaddr_buffer.h_addrtype = AF_INET;
// FIXME: Should we populate the hostent's address list here with a sockaddr_in for the provided host?
__gethostbyaddr_address_list_buffer[0] = nullptr;
__gethostbyaddr_buffer.h_addr_list = (char**)__gethostbyaddr_address_list_buffer;
__gethostbyaddr_buffer.h_length = 4;
return &__gethostbyaddr_buffer;
}
}
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