#include <libgen.h>
#include <syslog.h>
#include <sys/time.h>
+#include <limits.h>
+#include <ctype.h>
+#include <nss.h>
+#include <dlfcn.h>
#include <libcfs/util/param.h>
#include <linux/lnet/nidstr.h>
#include <linux/lustre/lustre_idl.h>
#define PERM_PATHNAME "/etc/lustre/perm.conf"
+#define LUSTRE_PASSWD "/etc/lustre/passwd"
+#define LUSTRE_GROUP "/etc/lustre/group"
+
+#define L_GETIDENTITY_LOOKUP_CMD "lookup"
+#define NSS_MODULES_MAX_NR 8
+#define NSS_MODULE_NAME_SIZE 32
+#define NSS_SYMBOL_NAME_LEN_MAX 256
+
+static int nss_pw_buf_len;
+static void *nss_pw_buf;
+static int nss_grent_buf_len;
+static void *nss_grent_buf;
+static int g_n_nss_modules;
+static int grent_mod_no = -1;
+
+struct nss_module {
+ char name[NSS_MODULE_NAME_SIZE];
+ int (*getpwuid)(struct nss_module *mod, uid_t, struct passwd *pwd);
+ int (*getgrent)(struct nss_module *mod, struct group *result);
+ void (*endgrent)(struct nss_module *mod);
+ void (*fini)(struct nss_module *mod);
+
+ union {
+ struct {
+ void *l_ptr;
+ int (*l_getpwuid)(uid_t, struct passwd *pwd,
+ char *buffer, size_t buflen,
+ int *errnop);
+ int (*l_getgrent)(struct group *result, char *buffer,
+ size_t buflen, int *errnop);
+ int (*l_endgrent)(void);
+ } lib;
+ struct {
+ FILE *f_passwd;
+ FILE *f_group;
+ } files;
+ } u;
+};
+
+static struct nss_module g_nss_modules[NSS_MODULES_MAX_NR];
+
+#define NSS_LIB_NAME_PATTERN "libnss_%s.so.2"
/*
* permission file format is like this:
"\nusage: %s {-d|mdtname} {uid}\n"
"Normally invoked as an upcall from Lustre, set via:\n"
"lctl set_param mdt.${mdtname}.identity_upcall={path to upcall}\n"
- "\t-d: debug, print values to stdout instead of Lustre\n",
+ "\t-d: debug, print values to stdout instead of Lustre\n"
+ "\tNSS support enabled\n",
progname);
}
-static int compare_u32(const void *v1, const void *v2)
-{
- return *(__u32 *)v1 - *(__u32 *)v2;
-}
-
static void errlog(const char *fmt, ...)
{
va_list args;
closelog();
}
+static int compare_gids(const void *v1, const void *v2)
+{
+ return (*(gid_t *)v1 - *(gid_t *)v2);
+}
+
+/** getpwuid() replacement */
+static struct passwd *getpwuid_nss(uid_t uid)
+{
+ static struct passwd pw;
+ int i;
+
+ for (i = 0; i < g_n_nss_modules; i++) {
+ struct nss_module *mod = g_nss_modules + i;
+
+ if (mod->getpwuid(mod, uid, &pw) == 0)
+ return &pw;
+ }
+ return NULL;
+}
+
+/**
+ * getgrent() replacement.
+ * simulate getgrent(3) across nss modules
+ */
+static struct group *getgrent_nss(void)
+{
+ static struct group grp;
+
+ if (grent_mod_no < 0)
+ grent_mod_no = 0;
+
+ while (grent_mod_no < g_n_nss_modules) {
+ struct nss_module *mod = g_nss_modules + grent_mod_no;
+
+ if (mod->getgrent(mod, &grp) == 0)
+ return &grp;
+ mod->endgrent(mod);
+ grent_mod_no++;
+ }
+ return NULL;
+}
+
+/** endgrent() replacement */
+static void endgrent_nss(void)
+{
+ if (grent_mod_no < g_n_nss_modules
+ && grent_mod_no >= 0) {
+ struct nss_module *mod = g_nss_modules+grent_mod_no;
+
+ mod->endgrent(mod);
+ }
+ grent_mod_no = -1;
+}
+
+/** lookup symbol in dynamically loaded nss module */
+static void *get_nss_sym(struct nss_module *mod, const char *op)
+{
+ void *res;
+ int bytes;
+ char symbuf[NSS_SYMBOL_NAME_LEN_MAX];
+
+ bytes = snprintf(symbuf, NSS_SYMBOL_NAME_LEN_MAX - 1, "_nss_%s_%s",
+ mod->name, op);
+ if (bytes >= NSS_SYMBOL_NAME_LEN_MAX - 1) {
+ errlog("symbol name too long\n");
+ return NULL;
+ }
+ res = dlsym(mod->u.lib.l_ptr, symbuf);
+ if (res == NULL)
+ errlog("cannot find symbol %s in nss module \"%s\": %s\n",
+ symbuf, mod->name, dlerror());
+ return res;
+}
+
+/** allocate bigger buffer */
+static void enlarge_nss_buffer(void **buf, int *bufsize)
+{
+ free(*buf);
+ *bufsize = *bufsize * 2;
+ *buf = malloc(*bufsize);
+ if (*buf == NULL) {
+ errlog("no memory to allocate bigger buffer of %d bytes\n",
+ *bufsize);
+ exit(-1);
+ }
+}
+
+static int getpwuid_nss_lib(struct nss_module *nss, uid_t uid,
+ struct passwd *pw)
+{
+ int tmp_errno, err;
+
+ while (1) {
+ err = nss->u.lib.l_getpwuid(uid, pw, nss_pw_buf,
+ nss_pw_buf_len, &tmp_errno);
+ if (err == NSS_STATUS_TRYAGAIN) {
+ if (tmp_errno == ERANGE) {
+ /* buffer too small */
+ enlarge_nss_buffer(&nss_pw_buf,
+ &nss_pw_buf_len);
+ }
+ continue;
+ }
+ break;
+ }
+ if (err == NSS_STATUS_SUCCESS)
+ return 0;
+ return -ENOENT;
+}
+
+static int getgrent_nss_lib(struct nss_module *nss, struct group *gr)
+{
+ int tmp_errno, err;
+
+ while (1) {
+ err = nss->u.lib.l_getgrent(gr, nss_grent_buf,
+ nss_grent_buf_len, &tmp_errno);
+ if (err == NSS_STATUS_TRYAGAIN) {
+ if (tmp_errno == ERANGE) {
+ /* buffer too small */
+ enlarge_nss_buffer(&nss_grent_buf,
+ &nss_grent_buf_len);
+ }
+ continue;
+ }
+ break;
+ }
+ if (err == NSS_STATUS_SUCCESS)
+ return 0;
+ return -ENOENT;
+}
+
+static void endgrent_nss_lib(struct nss_module *mod)
+{
+ mod->u.lib.l_endgrent();
+}
+
+/** destroy a "shared lib" nss module */
+static void fini_nss_lib_module(struct nss_module *mod)
+{
+ if (mod->u.lib.l_ptr)
+ dlclose(mod->u.lib.l_ptr);
+}
+
+/** load and initialize a "shared lib" nss module */
+static int init_nss_lib_module(struct nss_module *mod, char *name)
+{
+ char lib_file_name[sizeof(NSS_LIB_NAME_PATTERN) + sizeof(mod->name)];
+
+ if (strlen(name) >= sizeof(mod->name)) {
+ errlog("module name (%s) too long\n", name);
+ exit(1);
+ }
+
+ strncpy(mod->name, name, sizeof(mod->name));
+ mod->name[sizeof(mod->name) - 1] = '\0';
+
+ snprintf(lib_file_name, sizeof(lib_file_name), NSS_LIB_NAME_PATTERN,
+ name);
+
+ mod->getpwuid = getpwuid_nss_lib;
+ mod->getgrent = getgrent_nss_lib;
+ mod->endgrent = endgrent_nss_lib;
+ mod->fini = fini_nss_lib_module;
+
+ mod->u.lib.l_ptr = dlopen(lib_file_name, RTLD_NOW);
+ if (mod->u.lib.l_ptr == NULL) {
+ errlog("dl error %s\n", dlerror());
+ exit(1);
+ }
+ mod->u.lib.l_getpwuid = get_nss_sym(mod, "getpwuid_r");
+ if (mod->getpwuid == NULL)
+ exit(1);
+
+ mod->u.lib.l_getgrent = get_nss_sym(mod, "getgrent_r");
+ if (mod->getgrent == NULL)
+ exit(1);
+
+ mod->u.lib.l_endgrent = get_nss_sym(mod, "endgrent");
+ if (mod->endgrent == NULL)
+ exit(1);
+
+ return 0;
+}
+
+static void fini_lustre_nss_module(struct nss_module *mod)
+{
+ if (mod->u.files.f_passwd)
+ fclose(mod->u.files.f_passwd);
+ if (mod->u.files.f_group)
+ fclose(mod->u.files.f_group);
+}
+
+static int getpwuid_lustre_nss(struct nss_module *mod, uid_t uid,
+ struct passwd *pw)
+{
+ struct passwd *pos;
+
+ while ((pos = fgetpwent(mod->u.files.f_passwd)) != NULL) {
+ if (pos->pw_uid == uid) {
+ *pw = *pos;
+ return 0;
+ }
+ }
+ return -1;
+}
+
+static int getgrent_lustre_nss(struct nss_module *mod, struct group *gr)
+{
+ struct group *pos;
+
+ pos = fgetgrent(mod->u.files.f_group);
+ if (pos) {
+ *gr = *pos;
+ return 0;
+ }
+ return 1;
+}
+
+static void endgrent_lustre_nss(struct nss_module *mod)
+{
+}
+
+/** initialize module to access local /etc/lustre/passwd,group files */
+static int init_lustre_module(struct nss_module *mod)
+{
+ mod->fini = fini_lustre_nss_module;
+ mod->getpwuid = getpwuid_lustre_nss;
+ mod->getgrent = getgrent_lustre_nss;
+ mod->endgrent = endgrent_lustre_nss;
+
+ mod->u.files.f_passwd = fopen(LUSTRE_PASSWD, "r");
+ if (mod->u.files.f_passwd == NULL)
+ exit(1);
+
+ mod->u.files.f_group = fopen(LUSTRE_GROUP, "r");
+ if (mod->u.files.f_group == NULL)
+ exit(1);
+
+ snprintf(mod->name, sizeof(mod->name), "lustre");
+ return 0;
+}
+
+/** load and initialize the "nss" system */
+static void init_nss(void)
+{
+ nss_pw_buf_len = sysconf(_SC_GETPW_R_SIZE_MAX);
+ if (nss_pw_buf_len == -1) {
+ perror("sysconf");
+ exit(1);
+ }
+ nss_pw_buf = malloc(nss_pw_buf_len);
+ if (nss_pw_buf == NULL) {
+ perror("pw buffer allocation");
+ exit(1);
+ }
+
+ nss_grent_buf_len = sysconf(_SC_GETGR_R_SIZE_MAX);
+ if (nss_grent_buf_len == -1) {
+ perror("sysconf");
+ exit(1);
+ }
+ nss_grent_buf = malloc(nss_grent_buf_len);
+ if (nss_grent_buf == NULL) {
+ perror("grent buffer allocation");
+ exit(1);
+ }
+}
+
+/** unload "nss" */
+static void fini_nss(void)
+{
+ int i;
+
+ for (i = 0; i < g_n_nss_modules; i++) {
+ struct nss_module *mod = g_nss_modules + i;
+
+ mod->fini(mod);
+ }
+
+ free(nss_pw_buf);
+ free(nss_grent_buf);
+}
+
+/** get supplementary group info and fill downcall data */
+static int get_groups_nss(struct identity_downcall_data *data,
+ unsigned int maxgroups)
+{
+ struct passwd *pw;
+ struct group *gr;
+ gid_t *groups;
+ unsigned int ngroups = 0;
+ char *pw_name;
+ int i;
+
+ pw = getpwuid_nss(data->idd_uid);
+ if (pw == NULL) {
+ data->idd_err = errno ? errno : EIDRM;
+ errlog("no such user %u\n", data->idd_uid);
+ return -1;
+ }
+
+ data->idd_gid = pw->pw_gid;
+ pw_name = strdup(pw->pw_name);
+ groups = data->idd_groups;
+
+ while ((gr = getgrent_nss()) != NULL && ngroups < maxgroups) {
+ if (gr->gr_gid == pw->pw_gid)
+ continue;
+ if (!gr->gr_mem)
+ continue;
+ for (i = 0; gr->gr_mem[i]; i++) {
+ if (!strcmp(gr->gr_mem[i], pw_name)) {
+ groups[ngroups++] = gr->gr_gid;
+ break;
+ }
+ }
+ }
+
+ endgrent_nss();
+
+ if (ngroups > 0)
+ qsort(groups, ngroups, sizeof(*groups), compare_gids);
+ data->idd_ngroups = ngroups;
+
+ free(pw_name);
+ return 0;
+}
+
int get_groups_local(struct identity_downcall_data *data,
unsigned int maxgroups)
{
groups[ngroups++] = groups_tmp[i];
if (ngroups > 0)
- qsort(groups, ngroups, sizeof(*groups), compare_u32);
+ qsort(groups, ngroups, sizeof(*groups), compare_gids);
data->idd_ngroups = ngroups;
free(groups_tmp);
return 0;
}
+int get_groups_common(struct identity_downcall_data *data,
+ unsigned int maxgroups)
+{
+ if (g_n_nss_modules)
+ return get_groups_nss(data, maxgroups);
+ return get_groups_local(data, maxgroups);
+}
+
static inline int comment_line(char *line)
{
char *p = line;
return (uid == uid2);
}
-typedef struct {
+struct perm_type {
char *name;
__u32 bit;
-} perm_type_t;
+};
-static perm_type_t perm_types[] = {
+static struct perm_type perm_types[] = {
{ "setuid", CFS_SETUID_PERM },
{ "setgid", CFS_SETGID_PERM },
{ "setgrp", CFS_SETGRP_PERM },
{ 0 }
};
-static perm_type_t noperm_types[] = {
+static struct perm_type noperm_types[] = {
{ "nosetuid", CFS_SETUID_PERM },
{ "nosetgid", CFS_SETGID_PERM },
{ "nosetgrp", CFS_SETGRP_PERM },
{
char *start, *end;
char name[64];
- perm_type_t *pt;
+ struct perm_type *pt;
*perm = 0;
*noperm = 0;
return 0;
}
+static char *striml(char *s)
+{
+ while (isspace(*s))
+ s++;
+ return s;
+}
+
+static void check_new_nss_module(struct nss_module *mod)
+{
+ int i;
+
+ for (i = 0; i < g_n_nss_modules; i++) {
+ struct nss_module *pos = g_nss_modules + i;
+
+ if (!strcmp(mod->name, pos->name)) {
+ errlog("attempt to initialize \"%s\" module twice\n",
+ pos->name);
+ exit(-1);
+ }
+ }
+}
+
+/**
+ * Check and parse lookup db config line.
+ * File should start with 'lookup' followed by the modules
+ * to be loaded, for example:
+ *
+ * [/etc/lustre/perm.conf]
+ * lookup lustre ldap
+ *
+ * Should search, in order, first found wins:
+ * lustre [/etc/lustre/passwd and /etc/lustre/group]
+ * ldap
+ *
+ * Other common nss modules: nis sss db files
+ * Since historically 'files' has been used exclusively
+ * to mean 'lustre auth files' and disabled using local auth
+ * via libnss_files users must select 'nss_files' to explicitly
+ * enable libnss_files, which is an uncommon configuration.
+ */
+static int lookup_db_line_nss(char *line)
+{
+ char *p, *tok;
+ int ret = 0;
+
+ p = striml(line);
+ if (strncmp(p, L_GETIDENTITY_LOOKUP_CMD,
+ sizeof(L_GETIDENTITY_LOOKUP_CMD) - 1))
+ return -EAGAIN;
+
+ tok = strtok(p, " \t");
+ if (tok == NULL || strcmp(tok, L_GETIDENTITY_LOOKUP_CMD))
+ return -EIO;
+
+ while ((tok = strtok(NULL, " \t\n")) != NULL) {
+ struct nss_module *newmod = g_nss_modules + g_n_nss_modules;
+
+ if (g_n_nss_modules >= NSS_MODULES_MAX_NR)
+ return -ERANGE;
+
+ if (!strcmp(tok, "files") || !strcmp(tok, "lustre"))
+ ret = init_lustre_module(newmod);
+ else if (!strcmp(tok, "nss_files"))
+ ret = init_nss_lib_module(newmod, "files");
+ else
+ ret = init_nss_lib_module(newmod, tok);
+
+ if (ret)
+ break;
+ check_new_nss_module(newmod);
+ g_n_nss_modules++;
+ }
+
+ return ret;
+}
+
int get_perms(struct identity_downcall_data *data)
{
FILE *fp;
char line[PATH_MAX];
+ int ret;
fp = fopen(PERM_PATHNAME, "r");
if (!fp) {
while (fgets(line, sizeof(line), fp)) {
if (comment_line(line))
continue;
-
+ ret = lookup_db_line_nss(line); /* lookup parsed */
+ if (ret == 0)
+ continue;
if (parse_perm_line(data, line, sizeof(line))) {
errlog("parse line %s failed!\n", line);
data->idd_err = EINVAL;
progname = basename(argv[0]);
if (argc != 3) {
usage();
- goto out;
+ goto out_no_nss;
}
+ errno = 0;
uid = strtoul(argv[2], &end, 0);
- if (*end) {
+ if (*end != '\0' || end == argv[2] || errno != 0) {
errlog("%s: invalid uid '%s'\n", progname, argv[2]);
- goto out;
+ goto out_no_nss;
}
gettimeofday(&start, NULL);
maxgroups = NGROUPS_MAX;
if (maxgroups == -1) {
rc = -EINVAL;
- goto out;
+ goto out_no_nss;
}
retry:
goto retry;
}
rc = -ENOMEM;
- goto out;
+ goto out_no_nss;
}
memset(data, 0, size);
data->idd_magic = IDENTITY_DOWNCALL_MAGIC;
data->idd_uid = uid;
+
+ init_nss();
+
+ /* read permission database and/or load nss modules
+ * rc is -1 only when file exists and is not readable or
+ * content has format / syntax errors
+ */
+ rc = get_perms(data);
+ if (rc)
+ goto downcall;
+
/* get groups for uid */
- rc = get_groups_local(data, maxgroups);
+ rc = get_groups_common(data, maxgroups);
if (rc)
goto downcall;
size = offsetof(struct identity_downcall_data,
idd_groups[data->idd_ngroups]);
- /* read permission database */
- rc = get_perms(data);
gettimeofday(&idgot, NULL);
downcall:
out_params:
cfs_free_param_data(&path);
out:
+ fini_nss();
+out_no_nss:
if (data)
free(data);
return rc;
git://git.whamcloud.com / fs / lustre-release.git / commitdiff