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Diffstat (limited to '')
| -rw-r--r-- | src/ttyname.c | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/src/ttyname.c b/src/ttyname.c new file mode 100644 index 0000000..580bafd --- /dev/null +++ b/src/ttyname.c @@ -0,0 +1,336 @@ +/* + * Copyright (c) 2012-2018 Todd C. Miller <Todd.Miller@sudo.ws> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +/* + * This is an open source non-commercial project. Dear PVS-Studio, please check it. + * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com + */ + +#include <config.h> + +/* Large files not supported by procfs.h on Solaris. */ +#if defined(HAVE_STRUCT_PSINFO_PR_TTYDEV) +# undef _FILE_OFFSET_BITS +# undef _LARGE_FILES +#endif + +#include <sys/types.h> +#include <sys/stat.h> +#if defined(MAJOR_IN_MKDEV) +# include <sys/mkdev.h> +#elif defined(MAJOR_IN_SYSMACROS) +# include <sys/sysmacros.h> +#endif +#include <stdio.h> +#include <stdlib.h> +#ifdef HAVE_STRING_H +# include <string.h> +#endif /* HAVE_STRING_H */ +#ifdef HAVE_STRINGS_H +# include <strings.h> +#endif /* HAVE_STRINGS_H */ +#include <unistd.h> +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <dirent.h> +#if defined(HAVE_KINFO_PROC2_NETBSD) || defined (HAVE_KINFO_PROC_OPENBSD) || defined(HAVE_KINFO_PROC_44BSD) +# include <sys/sysctl.h> +#elif defined(HAVE_KINFO_PROC_FREEBSD) +# include <sys/sysctl.h> +# include <sys/user.h> +#endif +#if defined(HAVE_PROCFS_H) +# include <procfs.h> +#elif defined(HAVE_SYS_PROCFS_H) +# include <sys/procfs.h> +#endif +#ifdef HAVE_PSTAT_GETPROC +# include <sys/pstat.h> +#endif + +#include "sudo.h" + +/* + * How to access the tty device number in struct kinfo_proc. + */ +#if defined(HAVE_KINFO_PROC2_NETBSD) +# define SUDO_KERN_PROC KERN_PROC2 +# define sudo_kinfo_proc kinfo_proc2 +# define sudo_kp_tdev p_tdev +# define sudo_kp_namelen 6 +#elif defined(HAVE_KINFO_PROC_OPENBSD) +# define SUDO_KERN_PROC KERN_PROC +# define sudo_kinfo_proc kinfo_proc +# define sudo_kp_tdev p_tdev +# define sudo_kp_namelen 6 +#elif defined(HAVE_KINFO_PROC_FREEBSD) +# define SUDO_KERN_PROC KERN_PROC +# define sudo_kinfo_proc kinfo_proc +# define sudo_kp_tdev ki_tdev +# define sudo_kp_namelen 4 +#elif defined(HAVE_KINFO_PROC_44BSD) +# define SUDO_KERN_PROC KERN_PROC +# define sudo_kinfo_proc kinfo_proc +# define sudo_kp_tdev kp_eproc.e_tdev +# define sudo_kp_namelen 4 +#endif + +#if defined(sudo_kp_tdev) +/* + * Store the name of the tty to which the process is attached in name. + * Returns name on success and NULL on failure, setting errno. + */ +char * +get_process_ttyname(char *name, size_t namelen) +{ + struct sudo_kinfo_proc *ki_proc = NULL; + size_t size = sizeof(*ki_proc); + int mib[6], rc, serrno = errno; + char *ret = NULL; + debug_decl(get_process_ttyname, SUDO_DEBUG_UTIL) + + /* + * Lookup controlling tty for this process via sysctl. + * This will work even if std{in,out,err} are redirected. + */ + mib[0] = CTL_KERN; + mib[1] = SUDO_KERN_PROC; + mib[2] = KERN_PROC_PID; + mib[3] = (int)getpid(); + mib[4] = sizeof(*ki_proc); + mib[5] = 1; + do { + struct sudo_kinfo_proc *kp; + + size += size / 10; + if ((kp = realloc(ki_proc, size)) == NULL) { + rc = -1; + break; /* really out of memory. */ + } + ki_proc = kp; + rc = sysctl(mib, sudo_kp_namelen, ki_proc, &size, NULL, 0); + } while (rc == -1 && errno == ENOMEM); + errno = ENOENT; + if (rc != -1) { + if ((dev_t)ki_proc->sudo_kp_tdev != (dev_t)-1) { + errno = serrno; + ret = sudo_ttyname_dev(ki_proc->sudo_kp_tdev, name, namelen); + if (ret == NULL) { + sudo_debug_printf(SUDO_DEBUG_WARN|SUDO_DEBUG_LINENO|SUDO_DEBUG_ERRNO, + "unable to map device number %u to name", + ki_proc->sudo_kp_tdev); + } + } + } else { + sudo_debug_printf(SUDO_DEBUG_WARN|SUDO_DEBUG_LINENO|SUDO_DEBUG_ERRNO, + "unable to resolve tty via KERN_PROC"); + } + free(ki_proc); + + debug_return_str(ret); +} +#elif defined(HAVE_STRUCT_PSINFO_PR_TTYDEV) +/* + * Store the name of the tty to which the process is attached in name. + * Returns name on success and NULL on failure, setting errno. + */ +char * +get_process_ttyname(char *name, size_t namelen) +{ + char path[PATH_MAX], *ret = NULL; + struct psinfo psinfo; + ssize_t nread; + int fd, serrno = errno; + debug_decl(get_process_ttyname, SUDO_DEBUG_UTIL) + + /* Try to determine the tty from pr_ttydev in /proc/pid/psinfo. */ + snprintf(path, sizeof(path), "/proc/%u/psinfo", (unsigned int)getpid()); + if ((fd = open(path, O_RDONLY, 0)) != -1) { + nread = read(fd, &psinfo, sizeof(psinfo)); + close(fd); + if (nread == (ssize_t)sizeof(psinfo)) { + dev_t rdev = (dev_t)psinfo.pr_ttydev; +#if defined(_AIX) && defined(DEVNO64) + if ((psinfo.pr_ttydev & DEVNO64) && sizeof(dev_t) == 4) + rdev = makedev(major64(psinfo.pr_ttydev), minor64(psinfo.pr_ttydev)); +#endif + if (rdev != (dev_t)-1) { + errno = serrno; + ret = sudo_ttyname_dev(rdev, name, namelen); + goto done; + } + } + } + errno = ENOENT; + +done: + if (ret == NULL) + sudo_debug_printf(SUDO_DEBUG_WARN|SUDO_DEBUG_LINENO|SUDO_DEBUG_ERRNO, + "unable to resolve tty via %s", path); + + debug_return_str(ret); +} +#elif defined(__linux__) +/* + * Store the name of the tty to which the process is attached in name. + * Returns name on success and NULL on failure, setting errno. + */ +char * +get_process_ttyname(char *name, size_t namelen) +{ + const char path[] = "/proc/self/stat"; + char *cp, buf[1024]; + char *ret = NULL; + int serrno = errno; + ssize_t nread; + int fd; + debug_decl(get_process_ttyname, SUDO_DEBUG_UTIL) + + /* + * Try to determine the tty from tty_nr in /proc/self/stat. + * Ignore /proc/self/stat if it contains embedded NUL bytes. + */ + if ((fd = open(path, O_RDONLY | O_NOFOLLOW)) != -1) { + cp = buf; + while ((nread = read(fd, cp, buf + sizeof(buf) - cp)) != 0) { + if (nread == -1) { + if (errno == EAGAIN || errno == EINTR) + continue; + break; + } + cp += nread; + if (cp >= buf + sizeof(buf)) + break; + } + if (nread == 0 && memchr(buf, '\0', cp - buf) == NULL) { + /* + * Field 7 is the tty dev (0 if no tty). + * Since the process name at field 2 "(comm)" may include + * whitespace (including newlines), start at the last ')' found. + */ + *cp = '\0'; + cp = strrchr(buf, ')'); + if (cp != NULL) { + char *ep = cp; + const char *errstr; + int field = 1; + + while (*++ep != '\0') { + if (*ep == ' ') { + *ep = '\0'; + if (++field == 7) { + int tty_nr = strtonum(cp, INT_MIN, INT_MAX, &errstr); + if (errstr) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO, + "%s: tty device %s: %s", path, cp, errstr); + } + if (tty_nr != 0) { + /* + * Avoid sign extension when assigning tdev. + * tty_nr in /proc/self/stat is printed as a + * signed int but the actual device number is an + * unsigned int and dev_t is unsigned long long. + */ + dev_t tdev = (unsigned int)tty_nr; + errno = serrno; + ret = sudo_ttyname_dev(tdev, name, namelen); + goto done; + } + break; + } + cp = ep + 1; + } + } + } + } + } + errno = ENOENT; + +done: + if (fd != -1) + close(fd); + if (ret == NULL) + sudo_debug_printf(SUDO_DEBUG_WARN|SUDO_DEBUG_LINENO|SUDO_DEBUG_ERRNO, + "unable to resolve tty via %s", path); + + debug_return_str(ret); +} +#elif defined(HAVE_PSTAT_GETPROC) +/* + * Store the name of the tty to which the process is attached in name. + * Returns name on success and NULL on failure, setting errno. + */ +char * +get_process_ttyname(char *name, size_t namelen) +{ + struct pst_status pstat; + char *ret = NULL; + int rc, serrno = errno; + debug_decl(get_process_ttyname, SUDO_DEBUG_UTIL) + + /* + * Determine the tty from psdev in struct pst_status. + * We may get EOVERFLOW if the whole thing doesn't fit but that is OK. + */ + rc = pstat_getproc(&pstat, sizeof(pstat), (size_t)0, (int)getpid()); + if (rc != -1 || errno == EOVERFLOW) { + if (pstat.pst_term.psd_major != -1 && pstat.pst_term.psd_minor != -1) { + errno = serrno; + ret = sudo_ttyname_dev(makedev(pstat.pst_term.psd_major, + pstat.pst_term.psd_minor), name, namelen); + goto done; + } + } + errno = ENOENT; + +done: + if (ret == NULL) + sudo_debug_printf(SUDO_DEBUG_WARN|SUDO_DEBUG_LINENO|SUDO_DEBUG_ERRNO, + "unable to resolve tty via pstat"); + + debug_return_str(ret); +} +#else +/* + * Store the name of the tty to which the process is attached in name. + * Returns name on success and NULL on failure, setting errno. + */ +char * +get_process_ttyname(char *name, size_t namelen) +{ + char *tty; + debug_decl(get_process_ttyname, SUDO_DEBUG_UTIL) + + if ((tty = ttyname(STDIN_FILENO)) == NULL) { + if ((tty = ttyname(STDOUT_FILENO)) == NULL) + tty = ttyname(STDERR_FILENO); + } + if (tty != NULL) { + if (strlcpy(name, tty, namelen) < namelen) + debug_return_str(name); + errno = ERANGE; + sudo_debug_printf(SUDO_DEBUG_WARN|SUDO_DEBUG_LINENO|SUDO_DEBUG_ERRNO, + "unable to store tty from ttyname"); + } else { + sudo_debug_printf(SUDO_DEBUG_WARN|SUDO_DEBUG_LINENO|SUDO_DEBUG_ERRNO, + "unable to resolve tty via ttyname"); + errno = ENOENT; + } + + debug_return_str(NULL); +} +#endif |