#include <sys/epoll.h>
#include <termios.h>
#include <sys/signalfd.h>
+#include <grp.h>
#include "log.h"
#include "util.h"
#include "strv.h"
static char *arg_directory = NULL;
+static char *arg_user = NULL;
static int help(void) {
printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
"Spawn a minimal namespace container for debugging, testing and building.\n\n"
" -h --help Show this help\n"
- " -D --directory=NAME Root directory for the container\n",
+ " -D --directory=NAME Root directory for the container\n"
+ " -u --user=USER Run the command under specified user or uid\n",
program_invocation_short_name);
return 0;
static const struct option options[] = {
{ "help", no_argument, NULL, 'h' },
{ "directory", required_argument, NULL, 'D' },
+ { "user", optional_argument, NULL, 'u' },
{ NULL, 0, NULL, 0 }
};
assert(argc >= 0);
assert(argv);
- while ((c = getopt_long(argc, argv, "+hD:", options, NULL)) >= 0) {
+ while ((c = getopt_long(argc, argv, "+hD:u:", options, NULL)) >= 0) {
switch (c) {
break;
+ case 'u':
+ free(arg_user);
+ if (!(arg_user = strdup(optarg))) {
+ log_error("Failed to duplicate user name.");
+ return -ENOMEM;
+ }
+
+ break;
+
case '?':
return -EINVAL;
} MountPoint;
static const MountPoint mount_table[] = {
- { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
- { "/proc/sys", "/proc/sys", "bind", NULL, MS_BIND, true }, /* Bind mount first */
- { "/proc/sys", "/proc/sys", "bind", NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, true }, /* Then, make it r/o */
- { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, true },
- { "tmpfs", "/dev", "tmpfs", "mode=755", MS_NOSUID, true },
- { "/dev/pts", "/dev/pts", "bind", NULL, MS_BIND, true },
- { "tmpfs", "/dev/.run", "tmpfs", "mode=755", MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
+ { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
+ { "/proc/sys", "/proc/sys", "bind", NULL, MS_BIND, true }, /* Bind mount first */
+ { "/proc/sys", "/proc/sys", "bind", NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, true }, /* Then, make it r/o */
+ { "/sys", "/sys", "bind", NULL, MS_BIND, true }, /* Bind mount first */
+ { "/sys", "/sys", "bind", NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, true }, /* Then, make it r/o */
+ { "tmpfs", "/dev", "tmpfs", "mode=755", MS_NOSUID, true },
+ { "/dev/pts", "/dev/pts", "bind", NULL, MS_BIND, true },
+ { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV, true },
#ifdef HAVE_SELINUX
- { "selinux", "/selinux", "selinuxfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, false },
+ { "/selinux", "/selinux", "bind", NULL, MS_BIND, false }, /* Bind mount first */
+ { "/selinux", "/selinux", "bind", NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, false }, /* Then, make it r/o */
#endif
};
unsigned k;
int r = 0;
+ char *where;
for (k = 0; k < ELEMENTSOF(mount_table); k++) {
- char *where;
int t;
if (asprintf(&where, "%s/%s", dest, mount_table[k].where) < 0) {
free(where);
}
+ /* Fix the timezone, if possible */
+ if (asprintf(&where, "%s/%s", dest, "/etc/localtime") >= 0) {
+ mount("/etc/localtime", where, "bind", MS_BIND, NULL);
+ mount("/etc/localtime", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
+ free(where);
+ }
+
return r;
}
unsigned long l;
- for (l = 0; l <= MAX(63LU, (unsigned long) CAP_LAST_CAP); l ++) {
+ for (l = 0; l <= MAX(63LU, (unsigned long) CAP_LAST_CAP); l++) {
unsigned i;
for (i = 0; i < ELEMENTSOF(retain); i++)
/* If this capability is not known, EINVAL
* will be returned, let's ignore this. */
if (errno == EINVAL)
- continue;
+ break;
log_error("PR_CAPBSET_DROP failed: %m");
return -errno;
#define BUFFER_SIZE 1024
static int process_pty(int master, sigset_t *mask) {
+
char in_buffer[BUFFER_SIZE], out_buffer[BUFFER_SIZE];
size_t in_buffer_full = 0, out_buffer_full = 0;
struct epoll_event stdin_ev, stdout_ev, master_ev, signal_ev;
bool stdin_readable = false, stdout_writable = false, master_readable = false, master_writable = false;
- bool stdin_rhup = false, stdout_whup = false, master_rhup = false, master_whup = false;
int ep = -1, signal_fd = -1, r;
fd_nonblock(STDIN_FILENO, 1);
goto finish;
}
- do {
+ for (;;) {
struct epoll_event ev[16];
ssize_t k;
int i, nfds;
for (i = 0; i < nfds; i++) {
if (ev[i].data.fd == STDIN_FILENO) {
- if (!stdin_rhup && (ev[i].events & (EPOLLHUP|EPOLLIN)))
+ if (ev[i].events & (EPOLLIN|EPOLLHUP))
stdin_readable = true;
} else if (ev[i].data.fd == STDOUT_FILENO) {
- if (ev[i].events & EPOLLHUP) {
- stdout_writable = false;
- stdout_whup = true;
- }
-
- if (!stdout_whup && (ev[i].events & EPOLLOUT))
+ if (ev[i].events & (EPOLLOUT|EPOLLHUP))
stdout_writable = true;
} else if (ev[i].data.fd == master) {
- /* We don't connect EPOLLHUP to
- * master_whup here, since EPOLLHUP
- * can happen when noone has opened
- * the other side */
-
- if (!master_rhup && (ev[i].events & (EPOLLHUP|EPOLLIN)))
+ if (ev[i].events & (EPOLLIN|EPOLLHUP))
master_readable = true;
- if (!master_whup && (ev[i].events & EPOLLOUT))
+ if (ev[i].events & (EPOLLOUT|EPOLLHUP))
master_writable = true;
} else if (ev[i].data.fd == signal_fd) {
if ((n = read(signal_fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
if (n >= 0) {
+ log_error("Failed to read from signalfd: invalid block size");
r = -EIO;
goto finish;
}
if (errno != EINTR && errno != EAGAIN) {
+ log_error("Failed to read from signalfd: %m");
r = -errno;
goto finish;
}
struct winsize ws;
/* The window size changed, let's forward that. */
-
if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0)
ioctl(master, TIOCSWINSZ, &ws);
} else {
- r = -EINTR;
+ r = 0;
goto finish;
}
}
if ((k = read(STDIN_FILENO, in_buffer + in_buffer_full, BUFFER_SIZE - in_buffer_full)) < 0) {
- if (errno == EAGAIN)
+ if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
stdin_readable = false;
- else if (errno == EPIPE || errno == ECONNRESET || errno == EIO)
- k = 0;
else {
log_error("read(): %m");
+ r = -errno;
goto finish;
}
} else
in_buffer_full += (size_t) k;
-
- if (k == 0) {
- stdin_rhup = true;
- stdin_readable = false;
- shutdown(STDIN_FILENO, SHUT_RD);
- }
}
if (master_writable && in_buffer_full > 0) {
if ((k = write(master, in_buffer, in_buffer_full)) < 0) {
- if (errno == EAGAIN)
+ if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
master_writable = false;
- else if (errno == EPIPE || errno == ECONNRESET || errno == EIO) {
- master_whup = true;
- master_writable = false;
- } else {
+ else {
log_error("write(): %m");
+ r = -errno;
goto finish;
}
if ((k = read(master, out_buffer + out_buffer_full, BUFFER_SIZE - out_buffer_full)) < 0) {
- if (errno == EAGAIN)
+ if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
master_readable = false;
- else if (errno == EPIPE || errno == ECONNRESET || errno == EIO)
- k = 0;
else {
log_error("read(): %m");
+ r = -errno;
goto finish;
}
} else
out_buffer_full += (size_t) k;
-
- if (k == 0) {
- master_rhup = true;
- master_readable = false;
- }
}
if (stdout_writable && out_buffer_full > 0) {
if ((k = write(STDOUT_FILENO, out_buffer, out_buffer_full)) < 0) {
- if (errno == EAGAIN)
- stdout_writable = false;
- else if (errno == EPIPE || errno == ECONNRESET || errno == EIO) {
- stdout_whup = true;
+ if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
stdout_writable = false;
- } else {
+ else {
log_error("write(): %m");
+ r = -errno;
goto finish;
}
}
}
}
-
- if (stdin_rhup && in_buffer_full <= 0 && !master_whup) {
- master_whup = true;
- master_writable = false;
- }
-
- if (master_rhup && out_buffer_full <= 0 && !stdout_whup) {
- stdout_whup = true;
- stdout_writable = false;
- shutdown(STDOUT_FILENO, SHUT_WR);
- }
-
- } while (!stdout_whup || !master_whup);
+ }
finish:
if (ep >= 0)
/* child */
const char *hn;
+ const char *home = NULL;
+ uid_t uid = (uid_t) -1;
+ gid_t gid = (gid_t) -1;
const char *envp[] = {
- "HOME=/root",
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
- NULL,
+ NULL, /* TERM */
+ NULL, /* HOME */
+ NULL, /* USER */
+ NULL, /* LOGNAME */
NULL
};
- envp[2] = strv_find_prefix(environ, "TERM=");
+ envp[1] = strv_find_prefix(environ, "TERM=");
close_nointr_nofail(master);
if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0)
goto child_fail;
+ /* Mark / as private, in case somebody marked it shared */
+ if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) < 0)
+ goto child_fail;
+
if (mount_all(arg_directory) < 0)
goto child_fail;
if (drop_capabilities() < 0)
goto child_fail;
+ if (arg_user) {
+
+ if (get_user_creds((const char**)&arg_user, &uid, &gid, &home) < 0) {
+ log_error("get_user_creds() failed: %m");
+ goto child_fail;
+ }
+
+ if (mkdir_parents(home, 0775) < 0) {
+ log_error("mkdir_parents() failed: %m");
+ goto child_fail;
+ }
+
+ if (safe_mkdir(home, 0775, uid, gid) < 0) {
+ log_error("safe_mkdir() failed: %m");
+ goto child_fail;
+ }
+
+ if (initgroups((const char*)arg_user, gid) < 0) {
+ log_error("initgroups() failed: %m");
+ goto child_fail;
+ }
+
+ if (setresgid(gid, gid, gid) < 0) {
+ log_error("setregid() failed: %m");
+ goto child_fail;
+ }
+
+ if (setresuid(uid, uid, uid) < 0) {
+ log_error("setreuid() failed: %m");
+ goto child_fail;
+ }
+ }
+
+ if ((asprintf((char**)(envp + 2), "HOME=%s", home? home: "/root") < 0) ||
+ (asprintf((char**)(envp + 3), "USER=%s", arg_user? arg_user : "root") < 0) ||
+ (asprintf((char**)(envp + 4), "LOGNAME=%s", arg_user? arg_user : "root") < 0)) {
+ log_error("Out of memory");
+ goto child_fail;
+ }
+
if ((hn = file_name_from_path(arg_directory)))
sethostname(hn, strlen(hn));
if (argc > optind)
execvpe(argv[optind], argv + optind, (char**) envp);
else {
- chdir("/root");
+ chdir(home ? home : "/root");
execle("/bin/bash", "-bash", NULL, (char**) envp);
}
~ianmdlvl / elogind.git / blobdiff