X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fnspawn.c;h=b548b126c6e5dccae2a71abcfdc07a5659d64135;hp=8d7e0d03a973304662d8fbf757c7dae27356248f;hb=fa734f4da837abe6c893e75c95be78527db72c0f;hpb=4b7a6af440ee1a957fd8fe1c6ca3b7f310fdf77c diff --git a/src/nspawn.c b/src/nspawn.c index 8d7e0d03a..b548b126c 100644 --- a/src/nspawn.c +++ b/src/nspawn.c @@ -37,16 +37,20 @@ #include #include #include +#include + +#include #include "log.h" #include "util.h" #include "missing.h" #include "cgroup-util.h" -#include "sd-daemon.h" #include "strv.h" +#include "loopback-setup.h" static char *arg_directory = NULL; static char *arg_user = NULL; +static bool arg_private_network = false; static int help(void) { @@ -54,7 +58,8 @@ static int help(void) { "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" - " -u --user=USER Run the command under specified user or uid\n", + " -u --user=USER Run the command under specified user or uid\n" + " --private-network Disable network in container\n", program_invocation_short_name); return 0; @@ -62,11 +67,16 @@ static int help(void) { static int parse_argv(int argc, char *argv[]) { + enum { + ARG_PRIVATE_NETWORK = 0x100 + }; + static const struct option options[] = { - { "help", no_argument, NULL, 'h' }, - { "directory", required_argument, NULL, 'D' }, - { "user", optional_argument, NULL, 'u' }, - { NULL, 0, NULL, 0 } + { "help", no_argument, NULL, 'h' }, + { "directory", required_argument, NULL, 'D' }, + { "user", required_argument, NULL, 'u' }, + { "private-network", no_argument, NULL, ARG_PRIVATE_NETWORK }, + { NULL, 0, NULL, 0 } }; int c; @@ -100,6 +110,10 @@ static int parse_argv(int argc, char *argv[]) { break; + case ARG_PRIVATE_NETWORK: + arg_private_network = true; + break; + case '?': return -EINVAL; @@ -133,8 +147,8 @@ static int mount_all(const char *dest) { { "/dev/pts", "/dev/pts", "bind", NULL, MS_BIND, true }, { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV, true }, #ifdef HAVE_SELINUX - { "/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 */ + { "/sys/fs/selinux", "/sys/fs/selinux", "bind", NULL, MS_BIND, false }, /* Bind mount first */ + { "/sys/fs/selinux", "/sys/fs/selinux", "bind", NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, false }, /* Then, make it r/o */ #endif }; @@ -154,7 +168,7 @@ static int mount_all(const char *dest) { break; } - if ((t = path_is_mount_point(where)) < 0) { + if ((t = path_is_mount_point(where, false)) < 0) { log_error("Failed to detect whether %s is a mount point: %s", where, strerror(-t)); free(where); @@ -184,8 +198,10 @@ static int mount_all(const char *dest) { /* 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); + + if (mount("/etc/localtime", where, "bind", MS_BIND, NULL) >= 0) + mount("/etc/localtime", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL); + free(where); } @@ -314,7 +330,6 @@ static int copy_devnodes(const char *dest, const char *console) { } finish: - umask(u); return r; @@ -347,7 +362,7 @@ static int drop_capabilities(void) { unsigned long l; - for (l = 0; l <= MAX(63LU, (unsigned long) CAP_LAST_CAP); l++) { + for (l = 0; l <= cap_last_cap(); l++) { unsigned i; for (i = 0; i < ELEMENTSOF(retain); i++) @@ -358,12 +373,6 @@ static int drop_capabilities(void) { continue; if (prctl(PR_CAPBSET_DROP, l) < 0) { - - /* If this capability is not known, EINVAL - * will be returned, let's ignore this. */ - if (errno == EINVAL) - break; - log_error("PR_CAPBSET_DROP failed: %m"); return -errno; } @@ -386,11 +395,9 @@ static int is_os_tree(const char *path) { return r < 0 ? 0 : 1; } -#define BUFFER_SIZE 1024 - static int process_pty(int master, sigset_t *mask) { - char in_buffer[BUFFER_SIZE], out_buffer[BUFFER_SIZE]; + char in_buffer[LINE_MAX], out_buffer[LINE_MAX]; 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; @@ -511,9 +518,9 @@ static int process_pty(int master, sigset_t *mask) { (master_readable && out_buffer_full <= 0) || (stdout_writable && out_buffer_full > 0)) { - if (stdin_readable && in_buffer_full < BUFFER_SIZE) { + if (stdin_readable && in_buffer_full < LINE_MAX) { - if ((k = read(STDIN_FILENO, in_buffer + in_buffer_full, BUFFER_SIZE - in_buffer_full)) < 0) { + if ((k = read(STDIN_FILENO, in_buffer + in_buffer_full, LINE_MAX - in_buffer_full)) < 0) { if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO) stdin_readable = false; @@ -545,9 +552,9 @@ static int process_pty(int master, sigset_t *mask) { } } - if (master_readable && out_buffer_full < BUFFER_SIZE) { + if (master_readable && out_buffer_full < LINE_MAX) { - if ((k = read(master, out_buffer + out_buffer_full, BUFFER_SIZE - out_buffer_full)) < 0) { + if ((k = read(master, out_buffer + out_buffer_full, LINE_MAX - out_buffer_full)) < 0) { if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO) master_readable = false; @@ -699,8 +706,13 @@ int main(int argc, char *argv[]) { sigset_add_many(&mask, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1); assert_se(sigprocmask(SIG_BLOCK, &mask, NULL) == 0); - if ((pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWIPC|CLONE_NEWNS|CLONE_NEWPID|CLONE_NEWUTS, NULL)) < 0) { - log_error("clone() failed: %m"); + pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWIPC|CLONE_NEWNS|CLONE_NEWPID|CLONE_NEWUTS|(arg_private_network ? CLONE_NEWNET : 0), NULL); + if (pid < 0) { + if (errno == EINVAL) + log_error("clone() failed, do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in): %m"); + else + log_error("clone() failed: %m"); + goto finish; } @@ -713,6 +725,7 @@ int main(int argc, char *argv[]) { gid_t gid = (gid_t) -1; const char *envp[] = { "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", + "container=systemd-nspawn", /* LXC sets container=lxc, so follow the scheme here */ NULL, /* TERM */ NULL, /* HOME */ NULL, /* USER */ @@ -720,7 +733,7 @@ int main(int argc, char *argv[]) { NULL }; - envp[1] = strv_find_prefix(environ, "TERM="); + envp[2] = strv_find_prefix(environ, "TERM="); close_nointr_nofail(master); @@ -776,7 +789,9 @@ int main(int argc, char *argv[]) { goto child_fail; } - umask(0002); + umask(0022); + + loopback_setup(); if (drop_capabilities() < 0) goto child_fail; @@ -814,9 +829,9 @@ int main(int argc, char *argv[]) { } } - 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)) { + if ((asprintf((char**)(envp + 3), "HOME=%s", home? home: "/root") < 0) || + (asprintf((char**)(envp + 4), "USER=%s", arg_user? arg_user : "root") < 0) || + (asprintf((char**)(envp + 5), "LOGNAME=%s", arg_user? arg_user : "root") < 0)) { log_error("Out of memory"); goto child_fail; }