2 files changed, 0 insertions, 173 deletions
diff --git a/osdep/LinuxDropPrivileges.cpp b/osdep/LinuxDropPrivileges.cpp
deleted file mode 100644
index e2688e65..00000000
--- a/osdep/LinuxDropPrivileges.cpp
+++ /dev/null
@@ -1,164 +0,0 @@
-#include "LinuxDropPrivileges.hpp"
-#include <linux/capability.h>
-#include <linux/securebits.h>
-#include <sys/prctl.h>
-#include <sys/stat.h>
-#include <sys/syscall.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <pwd.h>
-#include <stdlib.h>
-#include <unistd.h>
-
-namespace ZeroTier {
-
-#ifndef PR_CAP_AMBIENT
-// if we are on old libc, dropPrivileges is nop
-void dropPrivileges(std::string homeDir) {}
-
-#else
-
-const char* TARGET_USER_NAME = "zerotier-one";
-
-struct cap_header_struct {
-    __u32 version;
-    int pid;
-};
-
-struct cap_data_struct {
-    __u32 effective;
-    __u32 permitted;
-    __u32 inheritable;
-};
-
-// libc doesn't export capset, it is instead located in libcap
-// We ignore libcap and call it manually.
-
-int capset(cap_header_struct* hdrp, cap_data_struct* datap) {
-    return syscall(SYS_capset, hdrp, datap);
-}
-
-void notDropping(std::string homeDir) {
-    struct stat buf;
-    if (lstat(homeDir.c_str(), &buf) < 0) {
-        if (buf.st_uid != 0 || buf.st_gid != 0) {
-            fprintf(stderr, "ERROR: failed to drop privileges. Refusing to run as root, because %s was already used in nonprivileged mode.\n", homeDir.c_str());
-            exit(1);
-        }
-    }
-    fprintf(stderr, "WARNING: failed to drop privileges, running as root\n");
-}
-
-int setCapabilities(int flags) {
-    cap_header_struct capheader = {_LINUX_CAPABILITY_VERSION_1, 0};
-    cap_data_struct capdata;
-    capdata.inheritable = capdata.permitted = capdata.effective = flags;
-    return capset(&capheader, &capdata);
-}
-
-void createOwnedHomedir(std::string homeDir, struct passwd* targetUser) {
-    struct stat buf;
-    if (lstat(homeDir.c_str(), &buf) < 0) {
-        if (errno == ENOENT) {
-            mkdir(homeDir.c_str(), 0755);
-        } else {
-            perror("cannot access home directory");
-            exit(1);
-        }
-    }
-
-    if (buf.st_uid != 0 || buf.st_gid != 0) {
-        // should be already owned by zerotier-one
-        if (targetUser->pw_uid != buf.st_uid) {
-            fprintf(stderr, "ERROR: %s not owned by zerotier-one or root\n", homeDir.c_str());
-            exit(1);
-        }
-        return;
-    }
-
-    // Change homedir owner to zerotier-one user. This is safe, because this directory is writable only by root, so no one could have created malicious hardlink.
-    long p = (long)fork();
-    int exitcode = -1;
-    if (p > 0) {
-        waitpid(p, &exitcode, 0);
-    } else if (p == 0) {
-        std::string ownerString = std::to_string(targetUser->pw_uid) + ":" + std::to_string(targetUser->pw_gid);
-        execlp("chown", "chown", "-R", ownerString.c_str(), "--", homeDir.c_str(), NULL);
-        _exit(-1);
-    }
-
-    if (exitcode != 0) {
-        fprintf(stderr, "failed to change owner of %s to %s\n", homeDir.c_str(), targetUser->pw_name);
-        exit(1);
-    }
-}
-
-void dropPrivileges(std::string homeDir) {
-    // dropPrivileges switches to zerotier-one user while retaining CAP_NET_ADMIN
-    // and CAP_NET_RAW capabilities.
-    struct passwd* targetUser = getpwnam(TARGET_USER_NAME);
-    if (targetUser == NULL) {
-        // zerotier-one user not configured by package
-        return;
-    }
-
-    createOwnedHomedir(homeDir, targetUser);
-
-    if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, CAP_NET_RAW, 0, 0) < 0) {
-        // Kernel has no support for ambient capabilities.
-        notDropping(homeDir);
-        return;
-    }
-
-    if (prctl(PR_SET_SECUREBITS, SECBIT_KEEP_CAPS | SECBIT_NOROOT) < 0) {
-        notDropping(homeDir);
-        return;
-    }
-
-    if (setCapabilities((1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | (1 << CAP_SETUID) | (1 << CAP_SETGID)) < 0) {
-        fprintf(stderr, "ERROR: failed to set capabilities (not running as real root?)\n");
-        exit(1);
-    }
-
-    int oldDumpable = prctl(PR_GET_DUMPABLE);
-
-    if (prctl(PR_SET_DUMPABLE, 0) < 0) {
-        // Disable ptracing. Otherwise there is a small window when previous
-        // compromised ZeroTier process could ptrace us, when we still have CAP_SETUID.
-        // (this is mitigated anyway on most distros by ptrace_scope=1)
-        perror("prctl(PR_SET_DUMPABLE)");
-        exit(1);
-    }
-
-    if (setgid(targetUser->pw_gid) < 0) {
-        perror("setgid");
-        exit(1);
-    }
-    if (setuid(targetUser->pw_uid) < 0) {
-        perror("setuid");
-        exit(1);
-    }
-
-    if (setCapabilities((1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW)) < 0) {
-        perror("could not drop capabilities after setuid");
-        exit(1);
-    }
-
-    if (prctl(PR_SET_DUMPABLE, oldDumpable) < 0) {
-        perror("could not restore dumpable flag");
-        exit(1);
-    }
-
-    if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, CAP_NET_ADMIN, 0, 0) < 0) {
-        perror("could not raise ambient CAP_NET_ADMIN");
-        exit(1);
-    }
-
-    if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, CAP_NET_RAW, 0, 0) < 0) {
-        perror("could not raise ambient CAP_NET_RAW");
-        exit(1);
-    }
-}
-
-#endif
-}
diff --git a/osdep/LinuxDropPrivileges.hpp b/osdep/LinuxDropPrivileges.hpp
deleted file mode 100644
index 111f682e..00000000
--- a/osdep/LinuxDropPrivileges.hpp
+++ /dev/null
@@ -1,9 +0,0 @@
-#ifndef ZT_LINUXDROPPRIVILEGES_HPP
-#define ZT_LINUXDROPPRIVILEGES_HPP
-#include <string>
-
-namespace ZeroTier {
-    void dropPrivileges(std::string homeDir);
-}
-
-#endif