From e42df368840ce96a4d561b4fec4d4ea07c30dbb6 Mon Sep 17 00:00:00 2001
From: Evgeny Zinoviev <me@ch1p.io>
Date: Sun, 29 Nov 2020 20:16:36 +0300
Subject: change name to voidnsrun, add command-line arguments, rewrite readme

---
 glibcrun.c | 101 -------------------------------------------------------------
 1 file changed, 101 deletions(-)
 delete mode 100644 glibcrun.c

(limited to 'glibcrun.c')

diff --git a/glibcrun.c b/glibcrun.c
deleted file mode 100644
index efedba1..0000000
--- a/glibcrun.c
+++ /dev/null
@@ -1,101 +0,0 @@
-/**
- * Copyright (c) 2020 Evgeny Zinoviev <me@ch1p.io>. 
- * 
- * This program is licensed under the BSD 2-Clause License.
- * https://opensource.org/licenses/BSD-2-Clause
- */
-
-#define _GNU_SOURCE
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <errno.h>
-#include <sched.h>
-#include <sys/mount.h>
-#include <sys/stat.h>
-#include <linux/limits.h>
-
-const char *var_name = "GLIBCRUN_DIR";
-
-#define ARRAY_SIZE(x)  (sizeof(x) / sizeof((x)[0]))
-#define ERROR(f_, ...) fprintf(stderr, (f_), ##__VA_ARGS__)
-
-int main(int argc, char *argv[]) {
-    int result;
-
-    /* Get glibc base path */
-    const char *dir = getenv(var_name);
-    if (!dir) {
-        ERROR("error: environment variable %s not found.\n", var_name);
-        return 1;
-    }
-
-    /* Validate it */
-    struct stat st;
-    result = stat(dir, &st);
-    if (result != 0 || !S_ISDIR(st.st_mode)) {
-        ERROR("error: %s is not a directory.\n", dir);
-        return 1;
-    }
-
-    /* Get shell from current env to reuse it if needed */
-    const char *shell = getenv("SHELL");
-    if (!shell)
-        shell = "/bin/sh";
-
-    /* Do the unshare magic */
-    result = unshare(CLONE_NEWNS);
-    if (result == -1) {
-        ERROR("unshare: %s\n", strerror(errno));
-        return 1;
-    }
-
-    /* Mount glibc stuff to our private namespace */
-    const char *const mountpoints[] = {"/usr", "/var/db/xbps"};
-    char buf[PATH_MAX];
-
-    for (int i = 0; i < (int)ARRAY_SIZE(mountpoints); i++) {
-        strcpy(buf, dir);
-        strcat(buf, mountpoints[i]);
-        result = mount(buf, mountpoints[i], NULL, MS_BIND|MS_REC, NULL);
-        if (result == -1) {
-            ERROR("mount(%s): %s\n", mountpoints[i], strerror(errno));
-            return 1;
-        }
-    }
-
-    /* Drop root */
-    uid_t uid = getuid();
-    gid_t gid = getgid();
-
-    result = setreuid(uid, uid);
-    if (result == -1) {
-        ERROR("setreuid: %s\n", strerror(errno));
-        return 1;
-    }
-
-    result = setregid(gid, gid);
-    if (result == -1) {
-        ERROR("setregid: %s\n", strerror(errno));
-        return 1;
-    }
-
-    /* Launch program or shell */
-    const char *exec_cmd;
-    char *const *exec_args = NULL;
-    if (argc < 2)
-        exec_cmd = shell;
-    else {
-        exec_cmd = argv[1];
-        exec_args = (char *const *)argv+1;
-    }
-
-    result = execvp(exec_cmd, exec_args);
-    if (result == -1) {
-        ERROR("execvp(%s): %s\n", exec_cmd, strerror(errno));
-        return 1;
-    }
-
-    return 0;
-}
-- 
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