diff options
Diffstat (limited to 'src/util.c')
| -rw-r--r-- | src/util.c | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/src/util.c b/src/util.c new file mode 100644 index 0000000..fea4b32 --- /dev/null +++ b/src/util.c @@ -0,0 +1,294 @@ +/*-------------------------------------------------------------------- + * Copyright © 2016 James Hunt <jamesodhunt@ubuntu.com>. + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + *-------------------------------------------------------------------- + */ + +#include "util.h" +#if __GLIBC__ +#include <sys/sysmacros.h> +#endif + +// FIXME +extern struct procenv_user user; +extern struct procenv_misc misc; + +struct baud_speed +{ + speed_t speed; + char *name; +}; + +/** + * fd_valid: + * @fd: file descriptor. + * + * Return 1 if @fd is valid, else 0. + **/ +int +fd_valid (int fd) +{ + int flags = 0; + + if (fd < 0) + return 0; + + errno = 0; + flags = fcntl (fd, F_GETFL); + + if (flags < 0) + return 0; + + /* redundant really */ + if (errno == EBADF) + return 0; + + return 1; +} + +#if !defined (PROCENV_PLATFORM_HURD) && \ + !defined (PROCENV_PLATFORM_MINIX) && \ + !defined (PROCENV_PLATFORM_DARWIN) + +/** + * is_console: + * @fd: open file descriptor. + * + * Check if specified file descriptor is attached to a _console_ + * device (physical or virtual). + * + * Notes: + * - ptys are NOT consoles :) + * - running inside screen/tmux will report not running on console. + * + * Returns: true if @fd is attached to a console, else false. + **/ +int +is_console (int fd) +{ + struct vt_mode vt; + int ret; + + ret = ioctl (fd, VT_GETMODE, &vt); + + return !ret; +} +#endif + +/** + * is_big_endian: + * + * Returns: true if system is big-endian, else false. + **/ +bool +is_big_endian (void) +{ + int x = 1; + + if (*(char *)&x == 1) + return false; + + return true; +} + +bool +has_ctty (void) +{ + int fd; + fd = open ("/dev/tty", O_RDONLY | O_NOCTTY); + + if (fd < 0) + return false; + + close (fd); + + return true; +} + +bool +uid_match (uid_t uid) +{ + return uid == getuid (); +} + +/** + * in_container: + * + * Determine if running inside a container. + * + * Returns: Name of container type, or NO_STR. + **/ +const char * +container_type (void) +{ + struct stat statbuf; + char buffer[1024]; + FILE *f; +#if defined (PROCENV_PLATFORM_LINUX) + dev_t expected; + + expected = makedev (5, 1); +#endif + + if (stat ("/dev/console", &statbuf) < 0) + goto out; + +#if defined (PROCENV_PLATFORM_FREEBSD) + if (misc.in_jail) + return "jail"; +#endif + + /* LXC's /dev/console is actually a pty */ +#if defined (PROCENV_PLATFORM_LINUX) + if (major (statbuf.st_rdev) != major (expected) + || (minor (statbuf.st_rdev)) != minor (expected)) + return "lxc"; +#endif + + if (! stat ("/proc/vz", &statbuf) && stat ("/proc/bc", &statbuf) < 0) + return "openvz"; + + f = fopen ("/proc/self/status", "r"); + if (! f) + goto out; + + while (fgets (buffer, sizeof (buffer), f)) { + size_t len = strlen (buffer); + buffer[len-1] = '\0'; + + if (strstr (buffer, "VxID") == buffer) { + fclose (f); + return "vserver"; + } + } + + fclose (f); + +out: + return NO_STR; +} + +/** + * in_chroot: + * + * Determine if running inside a chroot environment. + * + * Failures are fatal. + * + * Returns true if within a chroot, else false. + **/ +// FIXME: add different implementations? +bool +in_chroot (void) +{ + struct stat st; + int i; + int root_inode, self_inode; + char root[] = "/"; + char self[] = "/proc/self/root"; + char bsd_self[] = "/proc/curproc"; + char *dir = NULL; + + i = stat (root, &st); + if (i != 0) { + dir = root; + goto error; + } + + root_inode = st.st_ino; + + /* + * Inode 2 is the root inode for most filesystems. However, XFS + * uses 128 for root. + */ + if (root_inode != 2 && root_inode != 128) + return true; + + i = stat (bsd_self, &st); + if (i == 0) { + /* Give up here if running on BSD */ + return false; + } + + i = stat (self, &st); + if (i != 0) + return false; + + self_inode = st.st_ino; + + if (root_inode == self_inode) + return false; + + return true; + +error: + die ("cannot stat '%s'", dir); + + /* compiler appeasement */ + return false; +} + +/* detect if setsid(2) has been called */ +bool +is_session_leader (void) +{ + return user.sid == user.pid; +} + +/* detect if setpgrp(2)/setpgid(2) (or setsid(2)) has been called */ +bool +is_process_group_leader (void) +{ + return user.pgroup == user.pid; +} + +static struct baud_speed baud_speeds[] = { + SPEED (B0), + SPEED (B50), + SPEED (B75), + SPEED (B110), + SPEED (B134), + SPEED (B150), + SPEED (B200), + SPEED (B300), + SPEED (B600), + SPEED (B1200), + SPEED (B1800), + SPEED (B2400), + SPEED (B4800), + SPEED (B9600), + SPEED (B19200), + SPEED (B38400), + SPEED (B57600), + SPEED (B115200), + SPEED (B230400), + + /* terminator */ + { 0, NULL } +}; + +const char * +get_speed (speed_t speed) +{ + struct baud_speed *s; + + for (s = baud_speeds; s && s->name; s++) { + if (speed == s->speed) + return s->name; + } + + return NULL; +} + |