Adding upstream version 1:4.15.2.upstream/1%4.15.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 537 insertions, 0 deletions

diff --git a/lib/limits.c b/lib/limits.c
new file mode 100644
index 0000000..813c082
--- /dev/null
+++ b/lib/limits.c
@@ -0,0 +1,537 @@
+/*
+ * SPDX-FileCopyrightText: 1989 - 1994, Julianne Frances Haugh
+ * SPDX-FileCopyrightText: 1996 - 1999, Marek Michałkiewicz
+ * SPDX-FileCopyrightText: 2003 - 2006, Tomasz Kłoczko
+ * SPDX-FileCopyrightText: 2007 - 2010, Nicolas François
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/*
+ * Separated from setup.c.  --marekm
+ * Resource limits thanks to Cristian Gafton.
+ * Enhancements of resource limit code by Thomas Orgis <thomas@orgis.org>
+ */
+
+#include <config.h>
+
+#ifndef USE_PAM
+
+#ident "$Id$"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdio.h>
+#include <ctype.h>
+#include "prototypes.h"
+#include "defines.h"
+#include <pwd.h>
+#include "getdef.h"
+#include "shadowlog.h"
+#include <sys/resource.h>
+
+#include "atoi/str2i.h"
+#include "memzero.h"
+
+
+#ifndef LIMITS_FILE
+#define LIMITS_FILE "/etc/limits"
+#endif
+#define LOGIN_ERROR_RLIMIT	1
+#define LOGIN_ERROR_LOGIN	2
+/* Set a limit on a resource */
+/*
+ *	rlimit - RLIMIT_XXXX
+ *	value - string value to be read
+ *	multiplier - value*multiplier is the actual limit
+ */
+static int setrlimit_value (unsigned int resource,
+                            const char *value,
+                            unsigned int multiplier)
+{
+	char           *end;
+	long           l;
+	rlim_t         limit;
+	struct rlimit  rlim;
+
+	/* The "-" is special, not belonging to a strange negative limit.
+	 * It is infinity, in a controlled way.
+	 */
+	if ('-' == value[0]) {
+		limit = RLIM_INFINITY;
+	}
+	else {
+		/* We cannot use str2sl() here because it fails when there
+		 * is more to the value than just this number!
+		 * Also, we are limited to base 10 here (hex numbers will not
+		 * work with the limit string parser as is anyway)
+		 */
+		errno = 0;
+		l = strtol(value, &end, 10);
+
+		if (value == end || errno != 0)
+			return 0;  // FIXME: We could instead throw an error, though.
+
+		if (__builtin_mul_overflow(l, multiplier, &limit)) {
+			/* FIXME: Again, silent error handling...
+			 * Wouldn't screaming make more sense?
+			 */
+			return 0;
+		}
+	}
+
+	rlim.rlim_cur = limit;
+	rlim.rlim_max = limit;
+	if (setrlimit (resource, &rlim) != 0) {
+		return LOGIN_ERROR_RLIMIT;
+	}
+	return 0;
+}
+
+
+static int set_prio (const char *value)
+{
+	long prio;
+
+	if (   (str2sl(&prio, value) == -1)
+	    || (prio != (int) prio)) {
+		return 0;
+	}
+	if (setpriority (PRIO_PROCESS, 0, prio) != 0) {
+		return LOGIN_ERROR_RLIMIT;
+	}
+	return 0;
+}
+
+
+static int set_umask (const char *value)
+{
+	unsigned long  mask;
+
+	if (   (str2ul(&mask, value) == -1)
+	    || (mask != (mode_t) mask)) {
+		return 0;
+	}
+
+	(void) umask (mask);
+	return 0;
+}
+
+
+/* Counts the number of user logins and check against the limit */
+static int check_logins (const char *name, const char *maxlogins)
+{
+	unsigned long limit, count;
+
+	if (str2ul(&limit, maxlogins) == -1) {
+		return 0;
+	}
+
+	if (0 == limit) {	/* maximum 0 logins ? */
+		SYSLOG ((LOG_WARN, "No logins allowed for `%s'\n", name));
+		return LOGIN_ERROR_LOGIN;
+	}
+
+	count = active_sessions_count(name, limit);
+
+	if (count > limit) {
+		SYSLOG ((LOG_WARN,
+		         "Too many logins (max %lu) for %s\n",
+		         limit, name));
+		return LOGIN_ERROR_LOGIN;
+	}
+	return 0;
+}
+
+/* Function setup_user_limits - checks/set limits for the current login
+ * Original idea from Joel Katz's lshell. Ported to shadow-login
+ * by Cristian Gafton - gafton@sorosis.ro
+ *
+ * We are passed a string of the form ('BASH' constants for ulimit)
+ *     [Aa][Cc][Dd][Ff][Mm][Nn][Rr][Ss][Tt][Uu][Ll][Pp][Ii][Oo]
+ *     (eg. 'C2F256D2048N5' or 'C2 F256 D2048 N5')
+ * where:
+ * [Aa]: a = RLIMIT_AS		max address space (KB)
+ * [Cc]: c = RLIMIT_CORE	max core file size (KB)
+ * [Dd]: d = RLIMIT_DATA	max data size (KB)
+ * [Ff]: f = RLIMIT_FSIZE	max file size (KB)
+ * [Ii]: i = RLIMIT_NICE    max nice value (0..39 translates to 20..-19)
+ * [Kk]: k = file creation masK (umask)
+ * [Ll]: l = max number of logins for this user
+ * [Mm]: m = RLIMIT_MEMLOCK	max locked-in-memory address space (KB)
+ * [Nn]: n = RLIMIT_NOFILE	max number of open files
+ * [Oo]: o = RLIMIT_RTPRIO  max real time priority (linux/sched.h 0..MAX_RT_PRIO)
+ * [Pp]: p = process priority -20..20 (negative = high, positive = low)
+ * [Rr]: r = RLIMIT_RSS		max resident set size (KB)
+ * [Ss]: s = RLIMIT_STACK	max stack size (KB)
+ * [Tt]: t = RLIMIT_CPU		max CPU time (MIN)
+ * [Uu]: u = RLIMIT_NPROC	max number of processes
+ *
+ * NOTE: Remember to extend the "no-limits" string below when adding a new
+ * limit...
+ *
+ * Return value:
+ *		0 = okay, of course
+ *		LOGIN_ERROR_RLIMIT = error setting some RLIMIT
+ *		LOGIN_ERROR_LOGIN  = error - too many logins for this user
+ *
+ * buf - the limits string
+ * name - the username
+ */
+static int do_user_limits (const char *buf, const char *name)
+{
+	const char *pp;
+	int retval = 0;
+	bool reported = false;
+
+	pp = buf;
+	/* Skip leading whitespace. */
+	while ((' ' == *pp) || ('\t' == *pp)) {
+		pp++;
+	}
+
+	/* The special limit string "-" results in no limit for all known
+	 * limits.
+	 * We achieve that by parsing a full limit string, parts of it
+	 * being ignored if a limit type is not known to the system.
+	 * Though, there will be complaining for unknown limit types.
+	 */
+	if (strcmp (pp, "-") == 0) {
+		/* Remember to extend this, too, when adding new limits!
+		 * Oh... but "unlimited" does not make sense for umask,
+		 * or does it? (K-)
+		 */
+		pp = "A- C- D- F- I- L- M- N- O- P- R- S- T- U-";
+	}
+
+	while ('\0' != *pp) {
+		switch (*pp++) {
+		case 'a':
+		case 'A':
+			/* RLIMIT_AS - max address space (KB) */
+			retval |= setrlimit_value (RLIMIT_AS, pp, 1024);
+			break;
+		case 'c':
+		case 'C':
+			/* RLIMIT_CORE - max core file size (KB) */
+			retval |= setrlimit_value (RLIMIT_CORE, pp, 1024);
+			break;
+		case 'd':
+		case 'D':
+			/* RLIMIT_DATA - max data size (KB) */
+			retval |= setrlimit_value (RLIMIT_DATA, pp, 1024);
+			break;
+		case 'f':
+		case 'F':
+			/* RLIMIT_FSIZE - Maximum filesize (KB) */
+			retval |= setrlimit_value (RLIMIT_FSIZE, pp, 1024);
+			break;
+#ifdef RLIMIT_NICE
+		case 'i':
+		case 'I':
+			/* RLIMIT_NICE - max scheduling priority (0..39) */
+			retval |= setrlimit_value (RLIMIT_NICE, pp, 1);
+			break;
+#endif
+		case 'k':
+		case 'K':
+			retval |= set_umask (pp);
+			break;
+		case 'l':
+		case 'L':
+			/* LIMIT the number of concurrent logins */
+			retval |= check_logins (name, pp);
+			break;
+#ifdef RLIMIT_MEMLOCK
+		case 'm':
+		case 'M':
+			/* RLIMIT_MEMLOCK - max locked-in-memory address space (KB) */
+			retval |= setrlimit_value (RLIMIT_MEMLOCK, pp, 1024);
+			break;
+#endif
+		case 'n':
+		case 'N':
+			/* RLIMIT_NOFILE - max number of open files */
+			retval |= setrlimit_value (RLIMIT_NOFILE, pp, 1);
+			break;
+#ifdef RLIMIT_RTPRIO
+		case 'o':
+		case 'O':
+			/* RLIMIT_RTPRIO - max real time priority (0..MAX_RT_PRIO) */
+			retval |= setrlimit_value (RLIMIT_RTPRIO, pp, 1);
+			break;
+#endif
+		case 'p':
+		case 'P':
+			retval |= set_prio (pp);
+			break;
+#ifdef RLIMIT_RSS
+		case 'r':
+		case 'R':
+			/* RLIMIT_RSS - max resident set size (KB) */
+			retval |= setrlimit_value (RLIMIT_RSS, pp, 1024);
+			break;
+#endif
+		case 's':
+		case 'S':
+			/* RLIMIT_STACK - max stack size (KB) */
+			retval |= setrlimit_value (RLIMIT_STACK, pp, 1024);
+			break;
+		case 't':
+		case 'T':
+			/* RLIMIT_CPU - max CPU time (MIN) */
+			retval |= setrlimit_value (RLIMIT_CPU, pp, 60);
+			break;
+#ifdef RLIMIT_NPROC
+		case 'u':
+		case 'U':
+			/* RLIMIT_NPROC - max number of processes */
+			retval |= setrlimit_value (RLIMIT_NPROC, pp, 1);
+			break;
+#endif
+		default:
+			/* Only report invalid strings once */
+			/* Note: A string can be invalid just because a
+			 * specific (theoretically valid) setting is not
+			 * supported by this build.
+			 * It is just a warning in syslog anyway. The line
+			 * is still processed
+			 */
+			if (!reported) {
+				SYSLOG ((LOG_WARN,
+				         "Invalid limit string: '%s'",
+				         pp-1));
+				reported = true;
+				retval |= LOGIN_ERROR_RLIMIT;
+			}
+		}
+		/* After parsing one limit setting (or just complaining
+		 * about it), one still needs to skip its argument to
+		 * prevent a bogus warning on trying to parse that as
+		 * limit specification.
+		 * So, let's skip all digits, "-" and our limited set of
+		 * whitespace.
+		 */
+		while (   isdigit (*pp)
+		       || ('-'  == *pp)
+		       || (' '  == *pp)
+		       || ('\t' ==*pp)) {
+			pp++;
+		}
+	}
+	return retval;
+}
+
+/* Check if user uname is in the group gname.
+ * Can I be sure that gr_mem contains no UID as string?
+ * Returns true when user is in the group, false when not.
+ * Any error is treated as false.
+ */
+static bool user_in_group (const char *uname, const char *gname)
+{
+	struct group *groupdata;
+
+	if (uname == NULL || gname == NULL) {
+		return false;
+	}
+
+	/* We are not claiming to be re-entrant!
+	 * In case of paranoia or a multithreaded login program,
+	 * one needs to add some mess for getgrnam_r. */
+	groupdata = getgrnam (gname);
+	if (NULL == groupdata) {
+		SYSLOG ((LOG_WARN, "Nonexisting group `%s' in limits file.",
+		         gname));
+		return false;
+	}
+
+	return is_on_list (groupdata->gr_mem, uname);
+}
+
+static int setup_user_limits (const char *uname)
+{
+	FILE *fil;
+	char buf[1024];
+	char name[1024];
+	char limits[1024];
+	char deflimits[1024];
+	char tempbuf[1024];
+
+	/* init things */
+	MEMZERO(buf);
+	MEMZERO(name);
+	MEMZERO(limits);
+	MEMZERO(deflimits);
+	MEMZERO(tempbuf);
+
+	/* start the checks */
+	fil = fopen (LIMITS_FILE, "r");
+	if (fil == NULL) {
+		return 0;
+	}
+	/* The limits file have the following format:
+	 * - '#' (comment) chars only as first chars on a line;
+	 * - username must start on first column (or *, or @group)
+	 *
+	 * FIXME: A better (smarter) checking should be done
+	 */
+	while (fgets (buf, 1024, fil) != NULL) {
+		if (('#' == buf[0]) || ('\n' == buf[0])) {
+			continue;
+		}
+		MEMZERO(tempbuf);
+		/* a valid line should have a username, then spaces,
+		 * then limits
+		 * we allow the format:
+		 * username    L2  D2048  R4096
+		 * where spaces={' ',\t}. Also, we reject invalid limits.
+		 * Imposing a limit should be done with care, so a wrong
+		 * entry means no care anyway :-).
+		 *
+		 * A '-' as a limits strings means no limits
+		 *
+		 * The username can also be:
+		 *  '*': the default limits (only the last is taken into
+		 *       account)
+		 *  @group: the limit applies to the members of the group
+		 *
+		 * To clarify: The first entry with matching user name rules,
+		 * everything after it is ignored. If there is no user entry,
+		 * the last encountered entry for a matching group rules.
+		 * If there is no matching group entry, the default limits rule.
+		 */
+		if (sscanf (buf, "%s%[ACDFIKLMNOPRSTUacdfiklmnoprstu0-9 \t-]",
+		            name, tempbuf) == 2) {
+			if (strcmp (name, uname) == 0) {
+				strcpy (limits, tempbuf);
+				break;
+			} else if (strcmp (name, "*") == 0) {
+				strcpy (deflimits, tempbuf);
+			} else if (name[0] == '@') {
+				/* If the user is in the group, the group
+				 * limits apply unless later a line for
+				 * the specific user is found.
+				 */
+				if (user_in_group (uname, name+1)) {
+					strcpy (limits, tempbuf);
+				}
+			}
+		}
+	}
+	(void) fclose (fil);
+	if (limits[0] == '\0') {
+		/* no user specific limits */
+		if (deflimits[0] == '\0') {	/* no default limits */
+			return 0;
+		}
+		strcpy (limits, deflimits);	/* use the default limits */
+	}
+	return do_user_limits (limits, uname);
+}
+
+
+static void setup_usergroups (const struct passwd *info)
+{
+	const struct group *grp;
+
+/*
+ *	if not root, and UID == GID, and username is the same as primary
+ *	group name, set umask group bits to be the same as owner bits
+ *	(examples: 022 -> 002, 077 -> 007).
+ */
+	if ((0 != info->pw_uid) && (info->pw_uid == info->pw_gid)) {
+		/* local, no need for xgetgrgid */
+		grp = getgrgid (info->pw_gid);
+		if (   (NULL != grp)
+		    && (strcmp (info->pw_name, grp->gr_name) == 0)) {
+			mode_t tmpmask;
+			tmpmask = umask (0777);
+			tmpmask = (tmpmask & ~070) | ((tmpmask >> 3) & 070);
+			(void) umask (tmpmask);
+		}
+	}
+}
+
+/*
+ *	set the process nice, ulimit, and umask from the password file entry
+ */
+
+void setup_limits (const struct passwd *info)
+{
+	char *cp;
+
+	if (getdef_bool ("USERGROUPS_ENAB")) {
+		setup_usergroups (info);
+	}
+
+	/*
+	 * See if the GECOS field contains values for NICE, UMASK or ULIMIT.
+	 * If this feature is enabled in /etc/login.defs, we make those
+	 * values the defaults for this login session.
+	 */
+
+	if (getdef_bool ("QUOTAS_ENAB")) {
+		if (info->pw_uid != 0) {
+			if ((setup_user_limits (info->pw_name) & LOGIN_ERROR_LOGIN) != 0) {
+				(void) fputs (_("Too many logins.\n"), log_get_logfd());
+				(void) sleep (2); /* XXX: Should be FAIL_DELAY */
+				exit (EXIT_FAILURE);
+			}
+		}
+		for (cp = info->pw_gecos; cp != NULL; cp = strchr (cp, ',')) {
+			if (',' == *cp) {
+				cp++;
+			}
+
+			if (strncmp (cp, "pri=", 4) == 0) {
+				long  inc;
+
+				if (   (str2sl(&inc, cp + 4) == 0)
+				    && (inc >= -20) && (inc <= 20)) {
+					errno = 0;
+					if (   (nice (inc) != -1)
+					    || (0 != errno)) {
+						continue;
+					}
+				}
+
+				/* Failed to parse or failed to nice() */
+				SYSLOG ((LOG_WARN,
+				         "Can't set the nice value for user %s",
+				         info->pw_name));
+
+				continue;
+			}
+			if (strncmp (cp, "ulimit=", 7) == 0) {
+				long  blocks;
+				if (   (str2sl(&blocks, cp + 7) == -1)
+				    || (blocks != (int) blocks)
+				    || (set_filesize_limit (blocks) != 0)) {
+					SYSLOG ((LOG_WARN,
+					         "Can't set the ulimit for user %s",
+					         info->pw_name));
+				}
+				continue;
+			}
+			if (strncmp (cp, "umask=", 6) == 0) {
+				unsigned long  mask;
+
+				if (   (str2ul(&mask, cp + 6) == -1)
+				    || (mask != (mode_t) mask)) {
+					SYSLOG ((LOG_WARN,
+					         "Can't set umask value for user %s",
+					         info->pw_name));
+				} else {
+					(void) umask (mask);
+				}
+
+				continue;
+			}
+		}
+	}
+}
+
+#else				/* !USE_PAM */
+extern int ISO_C_forbids_an_empty_translation_unit;
+#endif				/* !USE_PAM */
+