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// SPDX-License-Identifier: MIT
/*
* Copyright (C) 2015-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <dirent.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#define SOCK_PATH RUNSTATEDIR "/wireguard/"
#define SOCK_SUFFIX ".sock"
static FILE *userspace_interface_file(const char *iface)
{
struct stat sbuf;
struct sockaddr_un addr = { .sun_family = AF_UNIX };
int fd = -1, ret;
FILE *f = NULL;
errno = EINVAL;
if (strchr(iface, '/'))
goto out;
ret = snprintf(addr.sun_path, sizeof(addr.sun_path), SOCK_PATH "%s" SOCK_SUFFIX, iface);
if (ret < 0)
goto out;
ret = stat(addr.sun_path, &sbuf);
if (ret < 0)
goto out;
errno = EBADF;
if (!S_ISSOCK(sbuf.st_mode))
goto out;
ret = fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (ret < 0)
goto out;
ret = connect(fd, (struct sockaddr *)&addr, sizeof(addr));
if (ret < 0) {
if (errno == ECONNREFUSED) /* If the process is gone, we try to clean up the socket. */
unlink(addr.sun_path);
goto out;
}
f = fdopen(fd, "r+");
if (f)
errno = 0;
out:
ret = -errno;
if (ret) {
if (fd >= 0)
close(fd);
errno = -ret;
return NULL;
}
return f;
}
static bool userspace_has_wireguard_interface(const char *iface)
{
struct stat sbuf;
struct sockaddr_un addr = { .sun_family = AF_UNIX };
int fd, ret;
if (strchr(iface, '/'))
return false;
if (snprintf(addr.sun_path, sizeof(addr.sun_path), SOCK_PATH "%s" SOCK_SUFFIX, iface) < 0)
return false;
if (stat(addr.sun_path, &sbuf) < 0)
return false;
if (!S_ISSOCK(sbuf.st_mode))
return false;
ret = fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (ret < 0)
return false;
ret = connect(fd, (struct sockaddr *)&addr, sizeof(addr));
if (ret < 0 && errno == ECONNREFUSED) { /* If the process is gone, we try to clean up the socket. */
close(fd);
unlink(addr.sun_path);
return false;
}
close(fd);
return true;
}
static int userspace_get_wireguard_interfaces(struct string_list *list)
{
DIR *dir;
struct dirent *ent;
size_t len;
char *end;
int ret = 0;
dir = opendir(SOCK_PATH);
if (!dir)
return errno == ENOENT ? 0 : -errno;
while ((ent = readdir(dir))) {
len = strlen(ent->d_name);
if (len <= strlen(SOCK_SUFFIX))
continue;
end = &ent->d_name[len - strlen(SOCK_SUFFIX)];
if (strncmp(end, SOCK_SUFFIX, strlen(SOCK_SUFFIX)))
continue;
*end = '\0';
if (!userspace_has_wireguard_interface(ent->d_name))
continue;
ret = string_list_add(list, ent->d_name);
if (ret < 0)
goto out;
}
out:
closedir(dir);
return ret;
}
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