paperclip/packages/tailscale-https-broker/src/peercred-native.c

65 lines
2.3 KiB
C

#define _GNU_SOURCE
#include <errno.h>
#include <node_api.h>
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
static napi_value throw_last_error(napi_env env, const char *operation) {
char message[256];
(void)snprintf(message, sizeof(message), "%s failed: %s", operation, strerror(errno));
napi_throw_error(env, NULL, message);
return NULL;
}
static napi_value get_peer_credentials(napi_env env, napi_callback_info info) {
size_t argc = 1;
napi_value argv[1];
int32_t fd;
if (napi_get_cb_info(env, info, &argc, argv, NULL, NULL) != napi_ok || argc != 1 ||
napi_get_value_int32(env, argv[0], &fd) != napi_ok || fd < 0) {
napi_throw_type_error(env, NULL, "getPeerCredentials requires a non-negative file descriptor");
return NULL;
}
struct ucred credentials;
socklen_t length = sizeof(credentials);
if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &credentials, &length) != 0) {
return throw_last_error(env, "getsockopt(SO_PEERCRED)");
}
if (length != sizeof(credentials) || credentials.pid < 0) {
napi_throw_error(env, NULL, "getsockopt(SO_PEERCRED) returned invalid credentials");
return NULL;
}
napi_value result;
napi_value pid;
napi_value uid;
napi_value gid;
if (napi_create_object(env, &result) != napi_ok ||
napi_create_int32(env, credentials.pid, &pid) != napi_ok ||
napi_create_uint32(env, credentials.uid, &uid) != napi_ok ||
napi_create_uint32(env, credentials.gid, &gid) != napi_ok ||
napi_set_named_property(env, result, "pid", pid) != napi_ok ||
napi_set_named_property(env, result, "uid", uid) != napi_ok ||
napi_set_named_property(env, result, "gid", gid) != napi_ok) {
napi_throw_error(env, NULL, "failed to create SO_PEERCRED result");
return NULL;
}
return result;
}
static napi_value initialize(napi_env env, napi_value exports) {
napi_value function;
if (napi_create_function(env, "getPeerCredentials", NAPI_AUTO_LENGTH,
get_peer_credentials, NULL, &function) != napi_ok ||
napi_set_named_property(env, exports, "getPeerCredentials", function) != napi_ok) {
napi_throw_error(env, NULL, "failed to initialize peercred native binding");
return NULL;
}
return exports;
}
NAPI_MODULE(NODE_GYP_MODULE_NAME, initialize)