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Diffstat (limited to 'source3/smbd/utmp.c')
| -rw-r--r-- | source3/smbd/utmp.c | 606 |
1 files changed, 606 insertions, 0 deletions
diff --git a/source3/smbd/utmp.c b/source3/smbd/utmp.c new file mode 100644 index 0000000000..6b7b0f3ad1 --- /dev/null +++ b/source3/smbd/utmp.c @@ -0,0 +1,606 @@ +/* + Unix SMB/CIFS implementation. + utmp routines + Copyright (C) T.D.Lee@durham.ac.uk 1999 + Heavily modified by Andrew Bartlett and Tridge, April 2001 + + 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 2 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, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +#include "includes.h" + +#ifdef WITH_UTMP + +/**************************************************************************** +Reflect connection status in utmp/wtmp files. + T.D.Lee@durham.ac.uk September 1999 + + With grateful thanks since then to many who have helped port it to + different operating systems. The variety of OS quirks thereby + uncovered is amazing... + +Hints for porting: + o Always attempt to use programmatic interface (pututline() etc.) + Indeed, at present only programmatic use is supported. + o The only currently supported programmatic interface to "wtmp{,x}" + is through "updwtmp*()" routines. + o The "x" (utmpx/wtmpx; HAVE_UTMPX_H) seems preferable. + o The HAVE_* items should identify supported features. + o If at all possible, avoid "if defined(MY-OS)" constructions. + +OS observations and status: + Almost every OS seems to have its own quirks. + + Solaris 2.x: + Tested on 2.6 and 2.7; should be OK on other flavours. + AIX: + Apparently has utmpx.h but doesn't implement. + OSF: + Has utmpx.h, but (e.g.) no "getutmpx()". (Is this like AIX ?) + Redhat 6: + utmpx.h seems not to set default filenames. non-x better. + IRIX 6.5: + Not tested. Appears to have "x". + HP-UX 9.x: + Not tested. Appears to lack "x". + HP-UX 10.x: + Not tested. + "updwtmp*()" routines seem absent, so no current wtmp* support. + Has "ut_addr": probably trivial to implement (although remember + that IPv6 is coming...). + + FreeBSD: + No "putut*()" type of interface. + No "ut_type" and associated defines. + Write files directly. Alternatively use its login(3)/logout(3). + SunOS 4: + Not tested. Resembles FreeBSD, but no login()/logout(). + +lastlog: + Should "lastlog" files, if any, be updated? + BSD systems (SunOS 4, FreeBSD): + o Prominent mention on man pages. + System-V (e.g. Solaris 2): + o No mention on man pages, even under "man -k". + o Has a "/var/adm/lastlog" file, but pututxline() etc. seem + not to touch it. + o Despite downplaying (above), nevertheless has <lastlog.h>. + So perhaps UN*X "lastlog" facility is intended for tty/terminal only? + +Notes: + Each connection requires a small number (starting at 0, working up) + to represent the line (unum). This must be unique within and across + all smbd processes. + + The 4 byte 'ut_id' component is vital to distinguish connections, + of which there could be several hundered or even thousand. + Entries seem to be printable characters, with optional NULL pads. + + We need to be distinct from other entries in utmp/wtmp. + + Observed things: therefore avoid them. Add to this list please. + From Solaris 2.x (because that's what I have): + 'sN' : run-levels; N: [0-9] + 'co' : console + 'CC' : arbitrary things; C: [a-z] + 'rXNN' : rlogin; N: [0-9]; X: [0-9a-z] + 'tXNN' : rlogin; N: [0-9]; X: [0-9a-z] + '/NNN' : Solaris CDE + 'ftpZ' : ftp (Z is the number 255, aka 0377, aka 0xff) + Mostly a record uses the same 'ut_id' in both "utmp" and "wtmp", + but differences have been seen. + + Arbitrarily I have chosen to use a distinctive 'SM' for the + first two bytes. + + The remaining two encode the "unum" (see above). + + For "utmp consolidate" the suggestion was made to encode the pid into + those remaining two bytes (16 bits). But recent UNIX (e.g Solaris 8) + is migrating to pids > 16 bits, so we ought not to do this. + +****************************************************************************/ + +#include <utmp.h> + +#ifdef HAVE_UTMPX_H +#include <utmpx.h> +#endif + +/* BSD systems: some may need lastlog.h (SunOS 4), some may not (FreeBSD) */ +/* Some System-V systems (e.g. Solaris 2) declare this too. */ +#ifdef HAVE_LASTLOG_H +#include <lastlog.h> +#endif + +/**************************************************************************** + Obtain/release a small number (0 upwards) unique within and across smbds. +****************************************************************************/ +/* + * Need a "small" number to represent this connection, unique within this + * smbd and across all smbds. + * + * claim: + * Start at 0, hunt up for free, unique number "unum" by attempting to + * store it as a key in a tdb database: + * key: unum data: pid+conn + * Also store its inverse, ready for yield function: + * key: pid+conn data: unum + * + * yield: + * Find key: pid+conn; data is unum; delete record + * Find key: unum ; delete record. + * + * Comment: + * The claim algorithm (a "for" loop attempting to store numbers in a tdb + * database) will be increasingly inefficient with larger numbers of + * connections. Is it possible to write a suitable primitive within tdb? + * + * However, by also storing the inverse key/data pair, we at least make + * the yield algorithm efficient. + */ + +/**************************************************************************** + Default paths to various {u,w}tmp{,x} files. +****************************************************************************/ + +#ifdef HAVE_UTMPX_H + +static const char *ux_pathname = +# if defined (UTMPX_FILE) + UTMPX_FILE ; +# elif defined (_UTMPX_FILE) + _UTMPX_FILE ; +# elif defined (_PATH_UTMPX) + _PATH_UTMPX ; +# else + "" ; +# endif + +static const char *wx_pathname = +# if defined (WTMPX_FILE) + WTMPX_FILE ; +# elif defined (_WTMPX_FILE) + _WTMPX_FILE ; +# elif defined (_PATH_WTMPX) + _PATH_WTMPX ; +# else + "" ; +# endif + +#endif /* HAVE_UTMPX_H */ + +static const char *ut_pathname = +# if defined (UTMP_FILE) + UTMP_FILE ; +# elif defined (_UTMP_FILE) + _UTMP_FILE ; +# elif defined (_PATH_UTMP) + _PATH_UTMP ; +# else + "" ; +# endif + +static const char *wt_pathname = +# if defined (WTMP_FILE) + WTMP_FILE ; +# elif defined (_WTMP_FILE) + _WTMP_FILE ; +# elif defined (_PATH_WTMP) + _PATH_WTMP ; +# else + "" ; +# endif + +/* BSD-like systems might want "lastlog" support. */ +/* *** Not yet implemented */ +#ifndef HAVE_PUTUTLINE /* see "pututline_my()" */ +static const char *ll_pathname = +# if defined (_PATH_LASTLOG) /* what other names (if any?) */ + _PATH_LASTLOG ; +# else + "" ; +# endif /* _PATH_LASTLOG */ +#endif /* HAVE_PUTUTLINE */ + +/* + * Get name of {u,w}tmp{,x} file. + * return: fname contains filename + * Possibly empty if this code not yet ported to this system. + * + * utmp{,x}: try "utmp dir", then default (a define) + * wtmp{,x}: try "wtmp dir", then "utmp dir", then default (a define) + */ +static void uw_pathname(pstring fname, const char *uw_name, const char *uw_default) +{ + pstring dirname; + + pstrcpy(dirname, ""); + + /* For w-files, first look for explicit "wtmp dir" */ + if (uw_name[0] == 'w') { + pstrcpy(dirname,lp_wtmpdir()); + trim_string(dirname,"","/"); + } + + /* For u-files and non-explicit w-dir, look for "utmp dir" */ + if (dirname == 0 || strlen(dirname) == 0) { + pstrcpy(dirname,lp_utmpdir()); + trim_string(dirname,"","/"); + } + + /* If explicit directory above, use it */ + if (dirname != 0 && strlen(dirname) != 0) { + pstrcpy(fname, dirname); + pstrcat(fname, "/"); + pstrcat(fname, uw_name); + return; + } + + /* No explicit directory: attempt to use default paths */ + if (strlen(uw_default) == 0) { + /* No explicit setting, no known default. + * Has it yet been ported to this OS? + */ + DEBUG(2,("uw_pathname: unable to determine pathname\n")); + } + pstrcpy(fname, uw_default); +} + +#ifndef HAVE_PUTUTLINE + +/**************************************************************************** + Update utmp file directly. No subroutine interface: probably a BSD system. +****************************************************************************/ + +static void pututline_my(pstring uname, struct utmp *u, BOOL claim) +{ + DEBUG(1,("pututline_my: not yet implemented\n")); + /* BSD implementor: may want to consider (or not) adjusting "lastlog" */ +} +#endif /* HAVE_PUTUTLINE */ + +#ifndef HAVE_UPDWTMP + +/**************************************************************************** + Update wtmp file directly. No subroutine interface: probably a BSD system. + Credit: Michail Vidiassov <master@iaas.msu.ru> +****************************************************************************/ + +static void updwtmp_my(pstring wname, struct utmp *u, BOOL claim) +{ + int fd; + struct stat buf; + + if (! claim) { + /* + * BSD-like systems: + * may use empty ut_name to distinguish a logout record. + * + * May need "if defined(SUNOS4)" etc. around some of these, + * but try to avoid if possible. + * + * SunOS 4: + * man page indicates ut_name and ut_host both NULL + * FreeBSD 4.0: + * man page appears not to specify (hints non-NULL) + * A correspondent suggest at least ut_name should be NULL + */ + memset((char *)&u->ut_name, '\0', sizeof(u->ut_name)); + memset((char *)&u->ut_host, '\0', sizeof(u->ut_host)); + } + /* Stolen from logwtmp function in libutil. + * May be more locking/blocking is needed? + */ + if ((fd = open(wname, O_WRONLY|O_APPEND, 0)) < 0) + return; + if (fstat(fd, &buf) == 0) { + if (write(fd, (char *)u, sizeof(struct utmp)) != sizeof(struct utmp)) + (void) ftruncate(fd, buf.st_size); + } + (void) close(fd); +} +#endif /* HAVE_UPDWTMP */ + +/**************************************************************************** + Update via utmp/wtmp (not utmpx/wtmpx). +****************************************************************************/ + +static void utmp_nox_update(struct utmp *u, BOOL claim) +{ + pstring uname, wname; +#if defined(PUTUTLINE_RETURNS_UTMP) + struct utmp *urc; +#endif /* PUTUTLINE_RETURNS_UTMP */ + + uw_pathname(uname, "utmp", ut_pathname); + DEBUG(2,("utmp_nox_update: uname:%s\n", uname)); + +#ifdef HAVE_PUTUTLINE + if (strlen(uname) != 0) { + utmpname(uname); + } + +# if defined(PUTUTLINE_RETURNS_UTMP) + setutent(); + urc = pututline(u); + endutent(); + if (urc == NULL) { + DEBUG(2,("utmp_nox_update: pututline() failed\n")); + return; + } +# else /* PUTUTLINE_RETURNS_UTMP */ + setutent(); + pututline(u); + endutent(); +# endif /* PUTUTLINE_RETURNS_UTMP */ + +#else /* HAVE_PUTUTLINE */ + if (strlen(uname) != 0) { + pututline_my(uname, u, claim); + } +#endif /* HAVE_PUTUTLINE */ + + uw_pathname(wname, "wtmp", wt_pathname); + DEBUG(2,("utmp_nox_update: wname:%s\n", wname)); + if (strlen(wname) != 0) { +#ifdef HAVE_UPDWTMP + updwtmp(wname, u); + /* + * updwtmp() and the newer updwtmpx() may be unsymmetrical. + * At least one OS, Solaris 2.x declares the former in the + * "utmpx" (latter) file and context. + * In the Solaris case this is irrelevant: it has both and + * we always prefer the "x" case, so doesn't come here. + * But are there other systems, with no "x", which lack + * updwtmp() perhaps? + */ +#else + updwtmp_my(wname, u, claim); +#endif /* HAVE_UPDWTMP */ + } +} + +/**************************************************************************** + Copy a string in the utmp structure. +****************************************************************************/ + +static void utmp_strcpy(char *dest, const char *src, size_t n) +{ + size_t len = 0; + + memset(dest, '\0', n); + if (src) + len = strlen(src); + if (len >= n) { + memcpy(dest, src, n); + } else { + if (len) + memcpy(dest, src, len); + } +} + +/**************************************************************************** + Update via utmpx/wtmpx (preferred) or via utmp/wtmp. +****************************************************************************/ + +static void sys_utmp_update(struct utmp *u, const char *hostname, BOOL claim) +{ +#if !defined(HAVE_UTMPX_H) + /* No utmpx stuff. Drop to non-x stuff */ + utmp_nox_update(u, claim); +#elif !defined(HAVE_PUTUTXLINE) + /* Odd. Have utmpx.h but no "pututxline()". Drop to non-x stuff */ + DEBUG(1,("utmp_update: have utmpx.h but no pututxline() function\n")); + utmp_nox_update(u, claim); +#elif !defined(HAVE_GETUTMPX) + /* Odd. Have utmpx.h but no "getutmpx()". Drop to non-x stuff */ + DEBUG(1,("utmp_update: have utmpx.h but no getutmpx() function\n")); + utmp_nox_update(u, claim); +#else + pstring uname, wname; + struct utmpx ux, *uxrc; + + getutmpx(u, &ux); + +#if defined(HAVE_UX_UT_SYSLEN) + if (hostname) + ux.ut_syslen = strlen(hostname) + 1; /* include end NULL */ + else + ux.ut_syslen = 0; +#endif + utmp_strcpy(ux.ut_host, hostname, sizeof(ux.ut_host)); + + uw_pathname(uname, "utmpx", ux_pathname); + uw_pathname(wname, "wtmpx", wx_pathname); + DEBUG(2,("utmp_update: uname:%s wname:%s\n", uname, wname)); + /* + * Check for either uname or wname being empty. + * Some systems, such as Redhat 6, have a "utmpx.h" which doesn't + * define default filenames. + * Also, our local installation has not provided an override. + * Drop to non-x method. (E.g. RH6 has good defaults in "utmp.h".) + */ + if ((strlen(uname) == 0) || (strlen(wname) == 0)) { + utmp_nox_update(u, claim); + } else { + utmpxname(uname); + setutxent(); + uxrc = pututxline(&ux); + endutxent(); + if (uxrc == NULL) { + DEBUG(2,("utmp_update: pututxline() failed\n")); + return; + } + updwtmpx(wname, &ux); + } +#endif /* HAVE_UTMPX_H */ +} + +#if defined(HAVE_UT_UT_ID) +/**************************************************************************** + Encode the unique connection number into "ut_id". +****************************************************************************/ + +static int ut_id_encode(int i, char *fourbyte) +{ + int nbase; + char *ut_id_encstr = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; + + fourbyte[0] = 'S'; + fourbyte[1] = 'M'; + +/* + * Encode remaining 2 bytes from 'i'. + * 'ut_id_encstr' is the character set on which modulo arithmetic is done. + * Example: digits would produce the base-10 numbers from '001'. + */ + nbase = strlen(ut_id_encstr); + + fourbyte[3] = ut_id_encstr[i % nbase]; + i /= nbase; + fourbyte[2] = ut_id_encstr[i % nbase]; + i /= nbase; + + return(i); /* 0: good; else overflow */ +} +#endif /* defined(HAVE_UT_UT_ID) */ + + +/* + fill a system utmp structure given all the info we can gather +*/ +static BOOL sys_utmp_fill(struct utmp *u, + const char *username, const char *hostname, + const char *id_str, int id_num) +{ + struct timeval timeval; + + /* + * ut_name, ut_user: + * Several (all?) systems seems to define one as the other. + * It is easier and clearer simply to let the following take its course, + * rather than to try to detect and optimise. + */ +#if defined(HAVE_UT_UT_USER) + utmp_strcpy(u->ut_user, username, sizeof(u->ut_user)); +#elif defined(HAVE_UT_UT_NAME) + utmp_strcpy(u->ut_name, username, sizeof(u->ut_name)); +#endif + + /* + * ut_line: + * If size limit proves troublesome, then perhaps use "ut_id_encode()". + * + * Temporary variable "line_tmp" avoids trouble: + * o with unwanted trailing NULL if ut_line full; + * o with overflow if ut_line would be more than full. + */ + if (strlen(id_str) > sizeof(u->ut_line)) { + DEBUG(1,("id_str [%s] is too long for %d char utmp field\n", + id_str, sizeof(u->ut_line))); + return False; + } + utmp_strcpy(u->ut_line, id_str, sizeof(u->ut_line)); + +#if defined(HAVE_UT_UT_PID) + u->ut_pid = sys_getpid(); +#endif + +/* + * ut_time, ut_tv: + * Some have one, some the other. Many have both, but defined (aliased). + * It is easier and clearer simply to let the following take its course. + * But note that we do the more precise ut_tv as the final assignment. + */ +#if defined(HAVE_UT_UT_TIME) + gettimeofday(&timeval, NULL); + u->ut_time = timeval.tv_sec; +#elif defined(HAVE_UT_UT_TV) + gettimeofday(&timeval, NULL); + u->ut_tv = timeval; +#else +#error "with-utmp must have UT_TIME or UT_TV" +#endif + +#if defined(HAVE_UT_UT_HOST) + utmp_strcpy(u->ut_host, hostname, sizeof(u->ut_host)); +#endif + +#if defined(HAVE_UT_UT_ADDR) + /* + * "(unsigned long) ut_addr" apparently exists on at least HP-UX 10.20. + * Volunteer to implement, please ... + */ +#endif + +#if defined(HAVE_UT_UT_ID) + if (ut_id_encode(id_num, u->ut_id) != 0) { + DEBUG(1,("utmp_fill: cannot encode id %d\n", id_num)); + return False; + } +#endif + + return True; +} + +/**************************************************************************** + Close a connection. +****************************************************************************/ + +void sys_utmp_yield(const char *username, const char *hostname, + const char *id_str, int id_num) +{ + struct utmp u; + + ZERO_STRUCT(u); + +#if defined(HAVE_UT_UT_EXIT) + u.ut_exit.e_termination = 0; + u.ut_exit.e_exit = 0; +#endif + +#if defined(HAVE_UT_UT_TYPE) + u.ut_type = DEAD_PROCESS; +#endif + + if (!sys_utmp_fill(&u, username, hostname, id_str, id_num)) return; + + sys_utmp_update(&u, NULL, False); +} + +/**************************************************************************** + Claim a entry in whatever utmp system the OS uses. +****************************************************************************/ + +void sys_utmp_claim(const char *username, const char *hostname, + const char *id_str, int id_num) +{ + struct utmp u; + + ZERO_STRUCT(u); + +#if defined(HAVE_UT_UT_TYPE) + u.ut_type = USER_PROCESS; +#endif + + if (!sys_utmp_fill(&u, username, hostname, id_str, id_num)) return; + + sys_utmp_update(&u, hostname, True); +} + +#else /* WITH_UTMP */ + void dummy_utmp(void) {} +#endif |