From 9620f76a210d9d8c1aaff25e99d6dc513f87e6e9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 04:23:56 +0200 Subject: Adding upstream version 1.8.27. Signed-off-by: Daniel Baumann --- src/utmp.c | 389 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 389 insertions(+) create mode 100644 src/utmp.c (limited to 'src/utmp.c') diff --git a/src/utmp.c b/src/utmp.c new file mode 100644 index 0000000..b371bbf --- /dev/null +++ b/src/utmp.c @@ -0,0 +1,389 @@ +/* + * Copyright (c) 2011-2018 Todd C. Miller + * + * 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 + +#include +#include +#include +#include +#include +#ifdef HAVE_STRING_H +# include +#endif /* HAVE_STRING_H */ +#ifdef HAVE_STRINGS_H +# include +#endif /* HAVE_STRINGS_H */ +#include +#include +#if defined(HAVE_UTMPS_H) +# include +#elif defined(HAVE_UTMPX_H) +# include +#else +# include +#endif /* HAVE_UTMPS_H */ +#ifdef HAVE_GETTTYENT +# include +#endif +#include +#include + +#include "sudo.h" +#include "sudo_exec.h" + +/* + * Simplify handling of different utmp types. + */ +#if defined(HAVE_GETUTSID) +# define sudo_getutline(u) GETUTSLINE(u) +# define sudo_pututline(u) PUTUTSLINE(u) +# define sudo_setutent() SETUTSENT() +# define sudo_endutent() ENDUTSENT() +#elif defined(HAVE_GETUTXID) +# define sudo_getutline(u) getutxline(u) +# define sudo_pututline(u) pututxline(u) +# define sudo_setutent() setutxent() +# define sudo_endutent() endutxent() +#elif defined(HAVE_GETUTID) +# define sudo_getutline(u) getutline(u) +# define sudo_pututline(u) pututline(u) +# define sudo_setutent() setutent() +# define sudo_endutent() endutent() +#endif + +#if defined(HAVE_GETUTSID) +typedef struct utmps sudo_utmp_t; +#elif defined(HAVE_GETUTXID) +typedef struct utmpx sudo_utmp_t; +#else +typedef struct utmp sudo_utmp_t; +/* Older systems have ut_name, not ut_user */ +# if !defined(HAVE_STRUCT_UTMP_UT_USER) && !defined(ut_user) +# define ut_user ut_name +# endif +#endif + +/* HP-UX has __e_termination and __e_exit, others may lack the __ */ +#if defined(HAVE_STRUCT_UTMP_UT_EXIT_E_TERMINATION) +# undef __e_termination +# define __e_termination e_termination +# undef __e_exit +# define __e_exit e_exit +#endif + +#if defined(HAVE_GETUTSID) || defined(HAVE_GETUTXID) || defined(HAVE_GETUTID) +/* + * Create ut_id from the new ut_line and the old ut_id. + */ +static void +utmp_setid(sudo_utmp_t *old, sudo_utmp_t *new) +{ + const char *line = new->ut_line; + size_t idlen; + debug_decl(utmp_setid, SUDO_DEBUG_UTMP) + + /* Skip over "tty" in the id if old entry did too. */ + if (old != NULL) { + /* cppcheck-suppress uninitdata */ + if (strncmp(line, "tty", 3) == 0) { + idlen = MIN(sizeof(old->ut_id), 3); + if (strncmp(old->ut_id, "tty", idlen) != 0) + line += 3; + } + } + + /* Store as much as will fit, skipping parts of the beginning as needed. */ + /* cppcheck-suppress uninitdata */ + idlen = strlen(line); + if (idlen > sizeof(new->ut_id)) { + line += idlen - sizeof(new->ut_id); + idlen = sizeof(new->ut_id); + } + strncpy(new->ut_id, line, idlen); + + debug_return; +} +#endif /* HAVE_GETUTSID || HAVE_GETUTXID || HAVE_GETUTID */ + +/* + * Store time in utmp structure. + */ +static void +utmp_settime(sudo_utmp_t *ut) +{ + struct timeval tv; + debug_decl(utmp_settime, SUDO_DEBUG_UTMP) + + if (gettimeofday(&tv, NULL) == 0) { +#if defined(HAVE_STRUCT_UTMP_UT_TV) + ut->ut_tv.tv_sec = tv.tv_sec; + ut->ut_tv.tv_usec = tv.tv_usec; +#else + ut->ut_time = tv.tv_sec; +#endif + } + + debug_return; +} + +/* + * Fill in a utmp entry, using an old entry as a template if there is one. + */ +static void +utmp_fill(const char *line, const char *user, sudo_utmp_t *ut_old, + sudo_utmp_t *ut_new) +{ + debug_decl(utmp_file, SUDO_DEBUG_UTMP) + + if (ut_old == NULL) { + memset(ut_new, 0, sizeof(*ut_new)); + if (user == NULL) { + strncpy(ut_new->ut_user, user_details.username, + sizeof(ut_new->ut_user)); + } + } else if (ut_old != ut_new) { + memcpy(ut_new, ut_old, sizeof(*ut_new)); + } + if (user != NULL) + strncpy(ut_new->ut_user, user, sizeof(ut_new->ut_user)); + strncpy(ut_new->ut_line, line, sizeof(ut_new->ut_line)); +#if defined(HAVE_STRUCT_UTMP_UT_ID) + utmp_setid(ut_old, ut_new); +#endif +#if defined(HAVE_STRUCT_UTMP_UT_PID) + ut_new->ut_pid = getpid(); +#endif + utmp_settime(ut_new); +#if defined(HAVE_STRUCT_UTMP_UT_TYPE) + ut_new->ut_type = USER_PROCESS; +#endif + debug_return; +} + +/* + * There are two basic utmp file types: + * + * POSIX: sequential access with new entries appended to the end. + * Manipulated via {get,put}[sx]?utent() + * + * Legacy: sparse file indexed by ttyslot() * sizeof(struct utmp) + */ +#if defined(HAVE_GETUTSID) || defined(HAVE_GETUTXID) || defined(HAVE_GETUTID) +bool +utmp_login(const char *from_line, const char *to_line, int ttyfd, + const char *user) +{ + sudo_utmp_t utbuf, *ut_old = NULL; + bool ret = false; + debug_decl(utmp_login, SUDO_DEBUG_UTMP) + + /* Strip off /dev/ prefix from line as needed. */ + if (strncmp(to_line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0) + to_line += sizeof(_PATH_DEV) - 1; + sudo_setutent(); + if (from_line != NULL) { + if (strncmp(from_line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0) + from_line += sizeof(_PATH_DEV) - 1; + + /* Lookup old line. */ + memset(&utbuf, 0, sizeof(utbuf)); + strncpy(utbuf.ut_line, from_line, sizeof(utbuf.ut_line)); + ut_old = sudo_getutline(&utbuf); + } + utmp_fill(to_line, user, ut_old, &utbuf); + if (sudo_pututline(&utbuf) != NULL) + ret = true; + sudo_endutent(); + + debug_return_bool(ret); +} + +bool +utmp_logout(const char *line, int status) +{ + bool ret = false; + sudo_utmp_t *ut, utbuf; + debug_decl(utmp_logout, SUDO_DEBUG_UTMP) + + /* Strip off /dev/ prefix from line as needed. */ + if (strncmp(line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0) + line += sizeof(_PATH_DEV) - 1; + + memset(&utbuf, 0, sizeof(utbuf)); + strncpy(utbuf.ut_line, line, sizeof(utbuf.ut_line)); + if ((ut = sudo_getutline(&utbuf)) != NULL) { + memset(ut->ut_user, 0, sizeof(ut->ut_user)); +# if defined(HAVE_STRUCT_UTMP_UT_TYPE) + ut->ut_type = DEAD_PROCESS; +# endif +# if defined(HAVE_STRUCT_UTMP_UT_EXIT) + ut->ut_exit.__e_termination = WIFSIGNALED(status) ? WTERMSIG(status) : 0; + ut->ut_exit.__e_exit = WIFEXITED(status) ? WEXITSTATUS(status) : 0; +# endif + utmp_settime(ut); + if (sudo_pututline(ut) != NULL) + ret = true; + } + debug_return_bool(ret); +} + +#else /* !HAVE_GETUTSID && !HAVE_GETUTXID && !HAVE_GETUTID */ + +/* + * Find the slot for the specified line (tty name and file descriptor). + * Returns a slot suitable for seeking into utmp on success or <= 0 on error. + * If getttyent() is available we can use that to compute the slot. + */ +# ifdef HAVE_GETTTYENT +static int +utmp_slot(const char *line, int ttyfd) +{ + int slot = 1; + struct ttyent *tty; + debug_decl(utmp_slot, SUDO_DEBUG_UTMP) + + setttyent(); + while ((tty = getttyent()) != NULL) { + if (strcmp(line, tty->ty_name) == 0) + break; + slot++; + } + endttyent(); + debug_return_int(tty ? slot : 0); +} +# else +static int +utmp_slot(const char *line, int ttyfd) +{ + int sfd, slot; + debug_decl(utmp_slot, SUDO_DEBUG_UTMP) + + /* + * Temporarily point stdin to the tty since ttyslot() + * doesn't take an argument. + */ + if ((sfd = dup(STDIN_FILENO)) == -1) + sudo_fatal(U_("unable to save stdin")); + if (dup2(ttyfd, STDIN_FILENO) == -1) + sudo_fatal(U_("unable to dup2 stdin")); + slot = ttyslot(); + if (dup2(sfd, STDIN_FILENO) == -1) + sudo_fatal(U_("unable to restore stdin")); + close(sfd); + + debug_return_int(slot); +} +# endif /* HAVE_GETTTYENT */ + +bool +utmp_login(const char *from_line, const char *to_line, int ttyfd, + const char *user) +{ + sudo_utmp_t utbuf, *ut_old = NULL; + bool ret = false; + int slot; + FILE *fp; + debug_decl(utmp_login, SUDO_DEBUG_UTMP) + + /* Strip off /dev/ prefix from line as needed. */ + if (strncmp(to_line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0) + to_line += sizeof(_PATH_DEV) - 1; + + /* Find slot for new entry. */ + slot = utmp_slot(to_line, ttyfd); + if (slot <= 0) + goto done; + + if ((fp = fopen(_PATH_UTMP, "r+")) == NULL) + goto done; + + if (from_line != NULL) { + if (strncmp(from_line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0) + from_line += sizeof(_PATH_DEV) - 1; + + /* Lookup old line. */ + while (fread(&utbuf, sizeof(utbuf), 1, fp) == 1) { +# ifdef HAVE_STRUCT_UTMP_UT_ID + if (utbuf.ut_type != LOGIN_PROCESS && utbuf.ut_type != USER_PROCESS) + continue; +# endif + if (utbuf.ut_user[0] && + !strncmp(utbuf.ut_line, from_line, sizeof(utbuf.ut_line))) { + ut_old = &utbuf; + break; + } + } + } + utmp_fill(to_line, user, ut_old, &utbuf); +# ifdef HAVE_FSEEKO + if (fseeko(fp, slot * (off_t)sizeof(utbuf), SEEK_SET) == 0) { +# else + if (fseek(fp, slot * (long)sizeof(utbuf), SEEK_SET) == 0) { +# endif + if (fwrite(&utbuf, sizeof(utbuf), 1, fp) == 1) + ret = true; + } + fclose(fp); + +done: + debug_return_bool(ret); +} + +bool +utmp_logout(const char *line, int status) +{ + sudo_utmp_t utbuf; + bool ret = false; + FILE *fp; + debug_decl(utmp_logout, SUDO_DEBUG_UTMP) + + if ((fp = fopen(_PATH_UTMP, "r+")) == NULL) + debug_return_int(ret); + + /* Strip off /dev/ prefix from line as needed. */ + if (strncmp(line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0) + line += sizeof(_PATH_DEV) - 1; + + while (fread(&utbuf, sizeof(utbuf), 1, fp) == 1) { + if (!strncmp(utbuf.ut_line, line, sizeof(utbuf.ut_line))) { + memset(utbuf.ut_user, 0, sizeof(utbuf.ut_user)); +# if defined(HAVE_STRUCT_UTMP_UT_TYPE) + utbuf.ut_type = DEAD_PROCESS; +# endif + utmp_settime(&utbuf); + /* Back up and overwrite record. */ +# ifdef HAVE_FSEEKO + if (fseeko(fp, (off_t)0 - (off_t)sizeof(utbuf), SEEK_CUR) == 0) { +# else + if (fseek(fp, 0L - (long)sizeof(utbuf), SEEK_CUR) == 0) { +# endif + if (fwrite(&utbuf, sizeof(utbuf), 1, fp) == 1) + ret = true; + } + break; + } + } + fclose(fp); + + debug_return_bool(ret); +} +#endif /* HAVE_GETUTSID || HAVE_GETUTXID || HAVE_GETUTID */ -- cgit v1.2.3