mirror of
https://github.com/RGBCube/serenity
synced 2025-06-01 10:58:11 +00:00
0e4a1936ca
We now talk to the lookup server over a local socket and it does the lookup on our behalf. Including some retry logic, which is nice, because it seems like DNS requests disappear in the ether pretty damn often where I am.
85 lines
2.1 KiB
C++
85 lines
2.1 KiB
C++
#include <netdb.h>
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#include <stdio.h>
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#include <string.h>
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#include <arpa/inet.h>
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#include <netinet/in.h>
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#include <unistd.h>
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#include <AK/Assertions.h>
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#include <AK/AKString.h>
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#include <Kernel/IPv4.h>
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extern "C" {
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static hostent __gethostbyname_buffer;
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static char __gethostbyname_name_buffer[512];
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static in_addr_t __gethostbyname_address;
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static in_addr_t* __gethostbyname_address_list_buffer[2];
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hostent* gethostbyname(const char* name)
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{
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int fd = socket(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0);
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if (fd < 0) {
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perror("socket");
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return nullptr;
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}
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sockaddr_un address;
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address.sun_family = AF_LOCAL;
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strcpy(address.sun_path, "/tmp/.DNSLookupServer-socket");
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int retries = 3;
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int rc = 0;
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while (retries) {
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rc = connect(fd, (const sockaddr*)&address, sizeof(address));
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if (rc == 0)
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break;
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--retries;
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sleep(1);
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}
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if (rc < 0) {
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close(fd);
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return nullptr;
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}
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auto line = String::format("%s\n", name);
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int nsent = write(fd, line.characters(), line.length());
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if (nsent < 0) {
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perror("send");
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close(fd);
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return nullptr;
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}
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ASSERT(nsent == line.length());
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char buffer[1024];
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int nrecv = read(fd, buffer, sizeof(buffer) - 1);
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if (nrecv < 0) {
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perror("recv");
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close(fd);
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return nullptr;
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}
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buffer[nrecv] = '\0';
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close(fd);
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if (!memcmp(buffer, "Not found.", sizeof("Not found.") - 1))
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return nullptr;
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rc = inet_pton(AF_INET, buffer, &__gethostbyname_address);
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if (rc < 0)
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return nullptr;
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strncpy(__gethostbyname_name_buffer, name, strlen(name));
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__gethostbyname_buffer.h_name = __gethostbyname_name_buffer;
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__gethostbyname_buffer.h_aliases = nullptr;
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__gethostbyname_buffer.h_addrtype = AF_INET;
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__gethostbyname_address_list_buffer[0] = &__gethostbyname_address;
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__gethostbyname_address_list_buffer[1] = nullptr;
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__gethostbyname_buffer.h_addr_list = (char**)__gethostbyname_address_list_buffer;
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__gethostbyname_buffer.h_length = 4;
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return &__gethostbyname_buffer;
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}
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}
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