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author | Steve Langasek <steve.langasek@ubuntu.com> | 2019-01-03 21:13:04 -0800 |
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committer | Steve Langasek <steve.langasek@ubuntu.com> | 2019-01-03 21:13:04 -0800 |
commit | c55c14c5c6762139ec6695d84ea0e2e917da5264 (patch) | |
tree | 9e6119760c93841b2bc3e05680ac9e4e15ae9c25 /modules/pam_limits/pam_limits.c | |
parent | f3c0273b7bd2d7fdcac3fe3604cedd82afc57f49 (diff) | |
parent | fc772e7236a7aea9c9c26b0be2ee6f3ed8ae444a (diff) | |
download | pam-c55c14c5c6762139ec6695d84ea0e2e917da5264.tar.gz pam-c55c14c5c6762139ec6695d84ea0e2e917da5264.tar.bz2 pam-c55c14c5c6762139ec6695d84ea0e2e917da5264.zip |
New upstream version 1.1.5
Diffstat (limited to 'modules/pam_limits/pam_limits.c')
-rw-r--r-- | modules/pam_limits/pam_limits.c | 367 |
1 files changed, 330 insertions, 37 deletions
diff --git a/modules/pam_limits/pam_limits.c b/modules/pam_limits/pam_limits.c index f446f9e3..c1810e07 100644 --- a/modules/pam_limits/pam_limits.c +++ b/modules/pam_limits/pam_limits.c @@ -51,9 +51,16 @@ #define LIMITS_DEF_USER 0 /* limit was set by an user entry */ #define LIMITS_DEF_GROUP 1 /* limit was set by a group entry */ #define LIMITS_DEF_ALLGROUP 2 /* limit was set by a group entry */ -#define LIMITS_DEF_ALL 3 /* limit was set by an default entry */ -#define LIMITS_DEF_DEFAULT 4 /* limit was set by an default entry */ -#define LIMITS_DEF_NONE 5 /* this limit was not set yet */ +#define LIMITS_DEF_ALL 3 /* limit was set by an all entry */ +#define LIMITS_DEF_DEFAULT 4 /* limit was set by a default entry */ +#define LIMITS_DEF_KERNEL 5 /* limit was set from /proc/1/limits */ +#define LIMITS_DEF_NONE 6 /* this limit was not set yet */ + +#define LIMIT_RANGE_ERR -1 /* error in specified uid/gid range */ +#define LIMIT_RANGE_NONE 0 /* no range specified */ +#define LIMIT_RANGE_ONE 1 /* exact uid/gid specified (:max_uid)*/ +#define LIMIT_RANGE_MIN 2 /* only minimum uid/gid specified (min_uid:) */ +#define LIMIT_RANGE_MM 3 /* both min and max uid/gid specified (min_uid:max_uid) */ static const char *limits_def_names[] = { "USER", @@ -61,6 +68,7 @@ static const char *limits_def_names[] = { "ALLGROUP", "ALL", "DEFAULT", + "KERNEL", "NONE", NULL }; @@ -103,9 +111,9 @@ struct pam_limit_s { /* argument parsing */ #define PAM_DEBUG_ARG 0x0001 -#define PAM_DO_SETREUID 0x0002 #define PAM_UTMP_EARLY 0x0004 #define PAM_NO_AUDIT 0x0008 +#define PAM_SET_ALL 0x0010 /* Limits from globbed files. */ #define LIMITS_CONF_GLOB LIMITS_FILE_DIR @@ -127,12 +135,12 @@ _pam_parse (const pam_handle_t *pamh, int argc, const char **argv, ctrl |= PAM_DEBUG_ARG; } else if (!strncmp(*argv,"conf=",5)) { pl->conf_file = *argv+5; - } else if (!strncmp(*argv,"change_uid",10)) { - ctrl |= PAM_DO_SETREUID; } else if (!strcmp(*argv,"utmp_early")) { ctrl |= PAM_UTMP_EARLY; } else if (!strcmp(*argv,"noaudit")) { ctrl |= PAM_NO_AUDIT; + } else if (!strcmp(*argv,"set_all")) { + ctrl |= PAM_SET_ALL; } else { pam_syslog(pamh, LOG_ERR, "unknown option: %s", *argv); } @@ -289,7 +297,140 @@ check_logins (pam_handle_t *pamh, const char *name, int limit, int ctrl, return 0; } -static int init_limits(struct pam_limit_s *pl) +static const char *lnames[RLIM_NLIMITS] = { + [RLIMIT_CPU] = "Max cpu time", + [RLIMIT_FSIZE] = "Max file size", + [RLIMIT_DATA] = "Max data size", + [RLIMIT_STACK] = "Max stack size", + [RLIMIT_CORE] = "Max core file size", + [RLIMIT_RSS] = "Max resident set", + [RLIMIT_NPROC] = "Max processes", + [RLIMIT_NOFILE] = "Max open files", + [RLIMIT_MEMLOCK] = "Max locked memory", +#ifdef RLIMIT_AS + [RLIMIT_AS] = "Max address space", +#endif +#ifdef RLIMIT_LOCKS + [RLIMIT_LOCKS] = "Max file locks", +#endif +#ifdef RLIMIT_SIGPENDING + [RLIMIT_SIGPENDING] = "Max pending signals", +#endif +#ifdef RLIMIT_MSGQUEUE + [RLIMIT_MSGQUEUE] = "Max msgqueue size", +#endif +#ifdef RLIMIT_NICE + [RLIMIT_NICE] = "Max nice priority", +#endif +#ifdef RLIMIT_RTPRIO + [RLIMIT_RTPRIO] = "Max realtime priority", +#endif +#ifdef RLIMIT_RTTIME + [RLIMIT_RTTIME] = "Max realtime timeout", +#endif +}; + +static int str2rlimit(char *name) { + int i; + if (!name || *name == '\0') + return -1; + for(i = 0; i < RLIM_NLIMITS; i++) { + if (strcmp(name, lnames[i]) == 0) return i; + } + return -1; +} + +static rlim_t str2rlim_t(char *value) { + unsigned long long rlimit = 0; + + if (!value) return (rlim_t)rlimit; + if (strcmp(value, "unlimited") == 0) { + return RLIM_INFINITY; + } + rlimit = strtoull(value, NULL, 10); + return (rlim_t)rlimit; +} + +#define LIMITS_SKIP_WHITESPACE { \ + /* step backwards over spaces */ \ + pos--; \ + while (pos && line[pos] == ' ') pos--; \ + if (!pos) continue; \ + line[pos+1] = '\0'; \ +} +#define LIMITS_MARK_ITEM(item) { \ + /* step backwards over non-spaces */ \ + pos--; \ + while (pos && line[pos] != ' ') pos--; \ + if (!pos) continue; \ + item = line + pos + 1; \ +} + +static void parse_kernel_limits(pam_handle_t *pamh, struct pam_limit_s *pl, int ctrl) +{ + int i, maxlen = 0; + FILE *limitsfile; + const char *proclimits = "/proc/1/limits"; + char line[256]; + char *units, *hard, *soft, *name; + + if (!(limitsfile = fopen(proclimits, "r"))) { + pam_syslog(pamh, LOG_WARNING, "Could not read %s (%s), using PAM defaults", proclimits, strerror(errno)); + return; + } + + while (fgets(line, 256, limitsfile)) { + int pos = strlen(line); + if (pos < 2) continue; + + /* drop trailing newline */ + if (line[pos-1] == '\n') { + pos--; + line[pos] = '\0'; + } + + /* determine formatting boundry of limits report */ + if (!maxlen && strncmp(line, "Limit", 5) == 0) { + maxlen = pos; + continue; + } + + if (pos == maxlen) { + /* step backwards over "Units" name */ + LIMITS_SKIP_WHITESPACE; + LIMITS_MARK_ITEM(units); + } + else { + units = ""; + } + + /* step backwards over "Hard Limit" value */ + LIMITS_SKIP_WHITESPACE; + LIMITS_MARK_ITEM(hard); + + /* step backwards over "Soft Limit" value */ + LIMITS_SKIP_WHITESPACE; + LIMITS_MARK_ITEM(soft); + + /* step backwards over name of limit */ + LIMITS_SKIP_WHITESPACE; + name = line; + + i = str2rlimit(name); + if (i < 0 || i >= RLIM_NLIMITS) { + if (ctrl & PAM_DEBUG_ARG) + pam_syslog(pamh, LOG_DEBUG, "Unknown kernel rlimit '%s' ignored", name); + continue; + } + pl->limits[i].limit.rlim_cur = str2rlim_t(soft); + pl->limits[i].limit.rlim_max = str2rlim_t(hard); + pl->limits[i].src_soft = LIMITS_DEF_KERNEL; + pl->limits[i].src_hard = LIMITS_DEF_KERNEL; + } + fclose(limitsfile); +} + +static int init_limits(pam_handle_t *pamh, struct pam_limit_s *pl, int ctrl) { int i; int retval = PAM_SUCCESS; @@ -310,6 +451,20 @@ static int init_limits(struct pam_limit_s *pl) } } +#ifdef __linux__ + if (ctrl & PAM_SET_ALL) { + parse_kernel_limits(pamh, pl, ctrl); + + for(i = 0; i < RLIM_NLIMITS; i++) { + if (pl->limits[i].supported && + (pl->limits[i].src_soft == LIMITS_DEF_NONE || + pl->limits[i].src_hard == LIMITS_DEF_NONE)) { + pam_syslog(pamh, LOG_WARNING, "Did not find kernel RLIMIT for %s, using PAM default", rlimit2str(i)); + } + } + } +#endif + errno = 0; pl->priority = getpriority (PRIO_PROCESS, 0); if (pl->priority == -1 && errno != 0) @@ -523,8 +678,57 @@ process_limit (const pam_handle_t *pamh, int source, const char *lim_type, return; } -static int parse_config_file(pam_handle_t *pamh, const char *uname, int ctrl, - struct pam_limit_s *pl) +static int +parse_uid_range(pam_handle_t *pamh, const char *domain, + uid_t *min_uid, uid_t *max_uid) +{ + const char *range = domain; + char *pmax; + char *endptr; + int rv = LIMIT_RANGE_MM; + + if ((pmax=strchr(range, ':')) == NULL) + return LIMIT_RANGE_NONE; + ++pmax; + + if (range[0] == '@' || range[0] == '%') + ++range; + + if (range[0] == ':') + rv = LIMIT_RANGE_ONE; + else { + errno = 0; + *min_uid = strtoul (range, &endptr, 10); + if (errno != 0 || (range == endptr) || *endptr != ':') { + pam_syslog(pamh, LOG_DEBUG, + "wrong min_uid/gid value in '%s'", domain); + return LIMIT_RANGE_ERR; + } + } + + if (*pmax == '\0') { + if (rv == LIMIT_RANGE_ONE) + return LIMIT_RANGE_ERR; + else + return LIMIT_RANGE_MIN; + } + + errno = 0; + *max_uid = strtoul (pmax, &endptr, 10); + if (errno != 0 || (pmax == endptr) || *endptr != '\0') { + pam_syslog(pamh, LOG_DEBUG, + "wrong max_uid/gid value in '%s'", domain); + return LIMIT_RANGE_ERR; + } + + if (rv == LIMIT_RANGE_ONE) + *min_uid = *max_uid; + return rv; +} + +static int +parse_config_file(pam_handle_t *pamh, const char *uname, uid_t uid, gid_t gid, + int ctrl, struct pam_limit_s *pl) { FILE *fil; char buf[LINE_LENGTH]; @@ -546,8 +750,10 @@ static int parse_config_file(pam_handle_t *pamh, const char *uname, int ctrl, char item[LINE_LENGTH]; char value[LINE_LENGTH]; int i; + int rngtype; size_t j; char *tptr,*line; + uid_t min_uid = (uid_t)-1, max_uid = (uid_t)-1; line = buf; /* skip the leading white space */ @@ -575,6 +781,11 @@ static int parse_config_file(pam_handle_t *pamh, const char *uname, int ctrl, for(j=0; j < strlen(ltype); j++) ltype[j]=tolower(ltype[j]); + if ((rngtype=parse_uid_range(pamh, domain, &min_uid, &max_uid)) < 0) { + pam_syslog(pamh, LOG_WARNING, "invalid uid range '%s' - skipped", domain); + continue; + } + if (i == 4) { /* a complete line */ for(j=0; j < strlen(item); j++) item[j]=tolower(item[j]); @@ -584,47 +795,133 @@ static int parse_config_file(pam_handle_t *pamh, const char *uname, int ctrl, if (strcmp(uname, domain) == 0) /* this user have a limit */ process_limit(pamh, LIMITS_DEF_USER, ltype, item, value, ctrl, pl); else if (domain[0]=='@') { - if (ctrl & PAM_DEBUG_ARG) { + if (ctrl & PAM_DEBUG_ARG) { pam_syslog(pamh, LOG_DEBUG, "checking if %s is in group %s", uname, domain + 1); - } - if (pam_modutil_user_in_group_nam_nam(pamh, uname, domain+1)) - process_limit(pamh, LIMITS_DEF_GROUP, ltype, item, value, ctrl, + } + switch(rngtype) { + case LIMIT_RANGE_NONE: + if (pam_modutil_user_in_group_nam_nam(pamh, uname, domain+1)) + process_limit(pamh, LIMITS_DEF_GROUP, ltype, item, value, ctrl, + pl); + break; + case LIMIT_RANGE_ONE: + if (pam_modutil_user_in_group_nam_gid(pamh, uname, (gid_t)max_uid)) + process_limit(pamh, LIMITS_DEF_GROUP, ltype, item, value, ctrl, pl); + break; + case LIMIT_RANGE_MM: + if (gid > (gid_t)max_uid) + break; + /* fallthrough */ + case LIMIT_RANGE_MIN: + if (gid >= (gid_t)min_uid) + process_limit(pamh, LIMITS_DEF_GROUP, ltype, item, value, ctrl, + pl); + } } else if (domain[0]=='%') { - if (ctrl & PAM_DEBUG_ARG) { + if (ctrl & PAM_DEBUG_ARG) { pam_syslog(pamh, LOG_DEBUG, "checking if %s is in group %s", uname, domain + 1); - } - if (strcmp(domain,"%") == 0) - process_limit(pamh, LIMITS_DEF_ALL, ltype, item, value, ctrl, - pl); - else if (pam_modutil_user_in_group_nam_nam(pamh, uname, domain+1)) { - strcpy(pl->login_group, domain+1); - process_limit(pamh, LIMITS_DEF_ALLGROUP, ltype, item, value, ctrl, - pl); } - } else if (strcmp(domain, "*") == 0) - process_limit(pamh, LIMITS_DEF_DEFAULT, ltype, item, value, ctrl, - pl); + switch(rngtype) { + case LIMIT_RANGE_NONE: + if (strcmp(domain,"%") == 0) + process_limit(pamh, LIMITS_DEF_ALL, ltype, item, value, ctrl, + pl); + else if (pam_modutil_user_in_group_nam_nam(pamh, uname, domain+1)) { + strcpy(pl->login_group, domain+1); + process_limit(pamh, LIMITS_DEF_ALLGROUP, ltype, item, value, ctrl, + pl); + } + break; + case LIMIT_RANGE_ONE: + if (pam_modutil_user_in_group_nam_gid(pamh, uname, (gid_t)max_uid)) { + struct group *grp; + grp = pam_modutil_getgrgid(pamh, (gid_t)max_uid); + strncpy(pl->login_group, grp->gr_name, sizeof(pl->login_group)); + pl->login_group[sizeof(pl->login_group)-1] = '\0'; + process_limit(pamh, LIMITS_DEF_ALLGROUP, ltype, item, value, ctrl, + pl); + } + break; + case LIMIT_RANGE_MIN: + case LIMIT_RANGE_MM: + pam_syslog(pamh, LOG_WARNING, "range unsupported for %%group matching - ignored"); + } + } else { + switch(rngtype) { + case LIMIT_RANGE_NONE: + if (strcmp(domain, "*") == 0) + process_limit(pamh, LIMITS_DEF_DEFAULT, ltype, item, value, ctrl, + pl); + break; + case LIMIT_RANGE_ONE: + if (uid != max_uid) + break; + /* fallthrough */ + case LIMIT_RANGE_MM: + if (uid > max_uid) + break; + /* fallthrough */ + case LIMIT_RANGE_MIN: + if (uid >= min_uid) + process_limit(pamh, LIMITS_DEF_USER, ltype, item, value, ctrl, pl); + } + } } else if (i == 2 && ltype[0] == '-') { /* Probably a no-limit line */ if (strcmp(uname, domain) == 0) { if (ctrl & PAM_DEBUG_ARG) { pam_syslog(pamh, LOG_DEBUG, "no limits for '%s'", uname); } - fclose(fil); - return PAM_IGNORE; - } else if (domain[0] == '@' && pam_modutil_user_in_group_nam_nam(pamh, uname, domain+1)) { + } else if (domain[0] == '@') { + switch(rngtype) { + case LIMIT_RANGE_NONE: + if (!pam_modutil_user_in_group_nam_nam(pamh, uname, domain+1)) + continue; /* next line */ + break; + case LIMIT_RANGE_ONE: + if (!pam_modutil_user_in_group_nam_gid(pamh, uname, (gid_t)max_uid)) + continue; /* next line */ + break; + case LIMIT_RANGE_MM: + if (gid > (gid_t)max_uid) + continue; /* next line */ + /* fallthrough */ + case LIMIT_RANGE_MIN: + if (gid < (gid_t)min_uid) + continue; /* next line */ + } if (ctrl & PAM_DEBUG_ARG) { pam_syslog(pamh, LOG_DEBUG, "no limits for '%s' in group '%s'", uname, domain+1); } - fclose(fil); - return PAM_IGNORE; + } else { + switch(rngtype) { + case LIMIT_RANGE_NONE: + continue; /* next line */ + case LIMIT_RANGE_ONE: + if (uid != max_uid) + continue; /* next line */ + break; + case LIMIT_RANGE_MM: + if (uid > max_uid) + continue; /* next line */ + /* fallthrough */ + case LIMIT_RANGE_MIN: + if (uid >= min_uid) + break; + continue; /* next line */ + } + if (ctrl & PAM_DEBUG_ARG) { + pam_syslog(pamh, LOG_DEBUG, "no limits for '%s'", uname); + } } + fclose(fil); + return PAM_IGNORE; } else { pam_syslog(pamh, LOG_WARNING, "invalid line '%s' - skipped", line); } @@ -728,13 +1025,13 @@ pam_sm_open_session (pam_handle_t *pamh, int flags UNUSED, return PAM_USER_UNKNOWN; } - retval = init_limits(pl); + retval = init_limits(pamh, pl, ctrl); if (retval != PAM_SUCCESS) { pam_syslog(pamh, LOG_WARNING, "cannot initialize"); return PAM_ABORT; } - retval = parse_config_file(pamh, pwd->pw_name, ctrl, pl); + retval = parse_config_file(pamh, pwd->pw_name, pwd->pw_uid, pwd->pw_gid, ctrl, pl); if (retval == PAM_IGNORE) { D(("the configuration file ('%s') has an applicable '<domain> -' entry", CONF_FILE)); return PAM_SUCCESS; @@ -758,7 +1055,7 @@ pam_sm_open_session (pam_handle_t *pamh, int flags UNUSED, /* Parse the *.conf files. */ for (i = 0; globbuf.gl_pathv[i] != NULL; i++) { pl->conf_file = globbuf.gl_pathv[i]; - retval = parse_config_file(pamh, pwd->pw_name, ctrl, pl); + retval = parse_config_file(pamh, pwd->pw_name, pwd->pw_uid, pwd->pw_gid, ctrl, pl); if (retval == PAM_IGNORE) { D(("the configuration file ('%s') has an applicable '<domain> -' entry", pl->conf_file)); globfree(&globbuf); @@ -777,10 +1074,6 @@ out: return retval; } - if (ctrl & PAM_DO_SETREUID) { - setreuid(pwd->pw_uid, -1); - } - retval = setup_limits(pamh, pwd->pw_name, pwd->pw_uid, ctrl, pl); if (retval & LOGIN_ERR) pam_error(pamh, _("Too many logins for '%s'."), pwd->pw_name); |