X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fnspawn.c;h=8ee940c2be59ceb04b0177dc02f2ed614954f9f1;hp=969c961895e3798dd5ad031ade9717eb6e681670;hb=f5c1b9eeb94c112e5dac09fc6a47c571356c30c0;hpb=0c749d504e98dddde3c39025b03744198a667fcc diff --git a/src/nspawn.c b/src/nspawn.c index 969c96189..8ee940c2b 100644 --- a/src/nspawn.c +++ b/src/nspawn.c @@ -36,6 +36,7 @@ #include #include #include +#include #include "log.h" #include "util.h" @@ -45,13 +46,15 @@ #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; @@ -62,6 +65,7 @@ static int parse_argv(int argc, char *argv[]) { static const struct option options[] = { { "help", no_argument, NULL, 'h' }, { "directory", required_argument, NULL, 'D' }, + { "user", optional_argument, NULL, 'u' }, { NULL, 0, NULL, 0 } }; @@ -70,7 +74,7 @@ static int parse_argv(int argc, char *argv[]) { 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) { @@ -87,6 +91,15 @@ static int parse_argv(int argc, char *argv[]) { break; + case 'u': + free(arg_user); + if (!(arg_user = strdup(optarg))) { + log_error("Failed to duplicate user name."); + return -ENOMEM; + } + + break; + case '?': return -EINVAL; @@ -111,15 +124,17 @@ static int mount_all(const char *dest) { } 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 }, + { "/proc", "/proc", "bind", NULL, MS_BIND, 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_NOEXEC|MS_NODEV, 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", "selinuxfs", NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, false }, /* Then, make it r/o */ #endif }; @@ -332,7 +347,7 @@ static int drop_capabilities(void) { 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++) @@ -347,7 +362,7 @@ static int drop_capabilities(void) { /* 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; @@ -693,14 +708,19 @@ int main(int argc, char *argv[]) { /* 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); @@ -721,6 +741,10 @@ int main(int argc, char *argv[]) { 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; @@ -757,13 +781,53 @@ int main(int argc, char *argv[]) { 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); }