From: Serge E. Hallyn <[email protected]> Add -t as an nsexec option to request new devpts.
Automatically remount /proc if we are starting a new pidns. Signed-off-by: Serge E. Hallyn <[email protected]> --- nsexec.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++-- 1 files changed, 48 insertions(+), 2 deletions(-) diff --git a/nsexec.c b/nsexec.c index 8b96bc9..3a825f1 100644 --- a/nsexec.c +++ b/nsexec.c @@ -15,6 +15,7 @@ #include <sys/stat.h> #include <sys/types.h> #include <sys/wait.h> +#include <sys/mount.h> #include "clone.h" #include "eclone.h" @@ -43,6 +44,7 @@ static void usage(const char *name) printf(" -i ipc namespace\n"); printf(" -P <pid-file> File in which to write global pid of cinit\n"); printf(" -p pid namespace\n"); + printf(" -t mount new devpts\n"); printf(" -f <flag> extra clone flags\n"); printf("\n"); printf("(C) Copyright IBM Corp. 2006\n"); @@ -189,6 +191,38 @@ int do_child(void *vargv) if (check_newcgrp()) return 1; + /* if pid == 1 then remount /proc */ + /* But if the container has no /proc don't fret */ + if (getpid() == 1) { + umount2("/proc", MNT_DETACH); + mount("proc", "/proc", "proc", 0, NULL); + } + + /* check if we should remount devpts */ + if (strcmp(argv[0], "newpts") == 0) { + struct stat ptystat; + argv++; + if (lstat("/dev/ptmx", &ptystat) < 0) { + perror("stat /dev/ptmx"); + return -1; + } + if ((ptystat.st_mode & S_IFMT) != S_IFLNK) { + printf("Error: /dev/ptmx must be a link to /dev/pts/ptmx\n"); + printf(" do: chmod 666 /dev/pts/ptmx\n"); + printf(" rm /dev/ptmx\n"); + printf(" ln -s /dev/pts/ptmx /dev/ptmx\n"); + return -1; + } + + /* if container had no /dev/pts mounted don't fret */ + umount2("/dev/pts", MNT_DETACH); + + if (mount("pts", "/dev/pts", "devpts", 0, "ptmxmode=666,newinstance") < 0) { + perror("mount -t devpts -o newinstance"); + return -1; + } + } + execve(argv[0], argv, __environ); perror("execve"); return 1; @@ -217,18 +251,19 @@ int main(int argc, char *argv[]) unsigned long flags = 0, eflags = 0; char ttyname[256]; int status; - int ret, use_clone = 0; + int ret, use_clone = 0, newpts = 0; int pid; char *pid_file = NULL; size_t nr_pids = 1; pid_t chosen_pid = 0; + char **newargv; procname = basename(argv[0]); memset(ttyname, '\0', sizeof(ttyname)); readlink("/proc/self/fd/0", ttyname, sizeof(ttyname)); - while ((c = getopt(argc, argv, "+mguUiphz:cnf:P:")) != EOF) { + while ((c = getopt(argc, argv, "+mguUiphz:cntf:P:")) != EOF) { switch (c) { case 'g': do_newcgrp = getpid(); break; case 'm': flags |= CLONE_NEWNS; break; @@ -239,6 +274,7 @@ int main(int argc, char *argv[]) case 'U': flags |= CLONE_NEWUSER; break; case 'n': flags |= CLONE_NEWNET; break; case 'p': flags |= CLONE_NEWNS|CLONE_NEWPID; break; + case 't': newpts = 1; flags |= CLONE_NEWNS; break; case 'z': chosen_pid = atoi(optarg); break; case 'f': if (!string_to_ul(optarg, &eflags)) { flags |= eflags; @@ -259,6 +295,16 @@ int main(int argc, char *argv[]) } argv = &argv[optind]; argc = argc - optind; + if (newpts) { + /* tell do_child about newpts through first arg */ + int i; + newargv = (char **) malloc(sizeof(char *) * (argc+2)); + newargv[0] = "newpts"; + newargv[argc+1] = NULL; + for (i=0; i<argc; i++) + newargv[i+1] = argv[i]; + argv = newargv; + } if (do_newcgrp) { ret = pipe(pipefd); -- 1.6.0.6 _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
