]> andersk Git - nss_nonlocal.git/blobdiff - nonlocal-group.c
Check that a nonlocal lookup by name returns the right name.
[nss_nonlocal.git] / nonlocal-group.c
index 0dfdb98f75c125ab9927476b1c5eabb30139cb13..83e5d12e385bbe5f8a1a640ed2712f9ded310937 100644 (file)
 #include "nsswitch-internal.h"
 #include "nonlocal.h"
 
-#define MAGIC_LOCAL_GR_BUFLEN (sysconf(_SC_GETGR_R_SIZE_MAX) + 7)
 #define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users"
 #define MAGIC_LOCAL_GROUPNAME "nss-local-users"
 
 
+enum nss_status
+_nss_nonlocal_getgrnam_r(const char *name, struct group *grp,
+                        char *buffer, size_t buflen, int *errnop);
+
+enum nss_status
+_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
+                        char *buffer, size_t buflen, int *errnop);
+
+
 static service_user *
 nss_group_nonlocal_database(void)
 {
@@ -60,87 +68,120 @@ nss_group_nonlocal_database(void)
 enum nss_status
 check_nonlocal_gid(const char *user, gid_t gid, int *errnop)
 {
-    enum nss_status status = NSS_STATUS_SUCCESS;
+    static const char *fct_name = "getgrgid_r";
+    static service_user *startp = NULL;
+    static void *fct_start = NULL;
+    enum nss_status status;
+    service_user *nip;
+    union {
+       enum nss_status (*l)(gid_t gid, struct group *grp,
+                            char *buffer, size_t buflen, int *errnop);
+       void *ptr;
+    } fct;
     struct group gbuf;
-    struct group *gbufp = &gbuf;
-    int ret;
     int old_errno = errno;
-    int buflen = MAGIC_LOCAL_GR_BUFLEN;
+
+    size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
     char *buf = malloc(buflen);
     if (buf == NULL) {
        *errnop = ENOMEM;
        errno = old_errno;
        return NSS_STATUS_TRYAGAIN;
     }
-    ret = getgrgid_r(gid, gbufp, buf, buflen, &gbufp);
-    if (ret != 0) {
-       *errnop = old_errno;
-       status = NSS_STATUS_TRYAGAIN;
-    } else if (gbufp != NULL) {
+
+    if (fct_start == NULL &&
+       __nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
+       free(buf);
+       return NSS_STATUS_UNAVAIL;
+    }
+    nip = startp;
+    fct.ptr = fct_start;
+    do {
+    morebuf:
+       if (fct.l == _nss_nonlocal_getgrgid_r)
+           status = NSS_STATUS_NOTFOUND;
+       else
+           status = DL_CALL_FCT(fct.l, (gid, &gbuf, buf, buflen, errnop));
+       if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) {
+           free(buf);
+           buflen *= 2;
+           buf = malloc(buflen);
+           if (buf == NULL) {
+               *errnop = ENOMEM;
+               errno = old_errno;
+               return NSS_STATUS_TRYAGAIN;
+           }
+           goto morebuf;
+       }
+    } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
+
+    if (status == NSS_STATUS_SUCCESS) {
        syslog(LOG_WARNING, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user);
        status = NSS_STATUS_NOTFOUND;
+    } else if (status != NSS_STATUS_TRYAGAIN) {
+       status = NSS_STATUS_SUCCESS;
     }
+
     free(buf);
-    errno = old_errno;
     return status;
 }
 
 enum nss_status
-get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen, int *errnop)
+get_local_group(const char *name, struct group *grp, char **buffer, int *errnop)
 {
-    enum nss_status status = NSS_STATUS_NOTFOUND;
-    struct group gbuf;
-    struct group *gbufp = &gbuf;
-    int ret, n;
+    static const char *fct_name = "getgrnam_r";
+    static service_user *startp = NULL;
+    static void *fct_start = NULL;
+    enum nss_status status;
+    service_user *nip;
+    union {
+       enum nss_status (*l)(const char *name, struct group *grp,
+                            char *buffer, size_t buflen, int *errnop);
+       void *ptr;
+    } fct;
+    size_t buflen;
     int old_errno = errno;
-    int len = MAGIC_LOCAL_GR_BUFLEN;
-    char *buf = malloc(len);
-    if (buf == NULL) {
+
+    buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
+    *buffer = malloc(buflen);
+    if (*buffer == NULL) {
        *errnop = ENOMEM;
        errno = old_errno;
        return NSS_STATUS_TRYAGAIN;
     }
-    ret = getgrnam_r(name, gbufp, buf, len, &gbufp);
-    if (ret != 0) {
-       *errnop = old_errno;
-       status = NSS_STATUS_TRYAGAIN;
-    } else if (gbufp != NULL) {
-       status = NSS_STATUS_SUCCESS;
 
-       n = snprintf(buffer, buflen, "%s", gbufp->gr_name);
-       if (n < 0 || n >= buflen) {
-           *errnop = ERANGE;
-           status = NSS_STATUS_TRYAGAIN;
-           goto get_local_group_done;
-       }
-       grp->gr_name = buffer;
-       buffer += n;
-       buflen -= n;
-
-       n = snprintf(buffer, buflen, "%s", gbufp->gr_passwd);
-       if (n < 0 || n >= buflen) {
-           *errnop = ERANGE;
-           status = NSS_STATUS_TRYAGAIN;
-           goto get_local_group_done;
+    if (fct_start == NULL &&
+       __nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
+       free(*buffer);
+       *buffer = NULL;
+       return NSS_STATUS_UNAVAIL;
+    }
+    nip = startp;
+    fct.ptr = fct_start;
+    do {
+    morebuf:
+       if (fct.l == _nss_nonlocal_getgrnam_r)
+           status = NSS_STATUS_NOTFOUND;
+       else
+           status = DL_CALL_FCT(fct.l, (name, grp, *buffer, buflen, errnop));
+       if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) {
+           free(*buffer);
+           buflen *= 2;
+           *buffer = malloc(buflen);
+           if (*buffer == NULL) {
+               *errnop = ENOMEM;
+               errno = old_errno;
+               return NSS_STATUS_TRYAGAIN;
+           }
+           goto morebuf;
        }
-       grp->gr_passwd = buffer;
-       buffer += n;
-       buflen -= n;
-
-       grp->gr_gid = gbufp->gr_gid;
+    } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
 
-       if (buflen < sizeof(void *)) {
-           *errnop = ERANGE;
-           status = NSS_STATUS_TRYAGAIN;
-           goto get_local_group_done;
-       }
-       *(void **)buffer = NULL;
-       buffer += sizeof(void *);
-       buflen -= sizeof(void *);
+    if (status != NSS_STATUS_SUCCESS) {
+       free(*buffer);
+       *buffer = NULL;
     }
- get_local_group_done:
-    free(buf);
-    errno = old_errno;
+
     return status;
 }
 
@@ -223,8 +264,7 @@ _nss_nonlocal_getgrent_r(struct group *grp, char *buffer, size_t buflen,
     enum nss_status status;
 
     char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
-    if (buflen == MAGIC_LOCAL_GR_BUFLEN ||
-       (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
+    if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
        return NSS_STATUS_UNAVAIL;
 
     if (grent_nip == NULL) {
@@ -269,8 +309,7 @@ _nss_nonlocal_getgrnam_r(const char *name, struct group *grp,
     } fct;
 
     char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
-    if (buflen == MAGIC_LOCAL_GR_BUFLEN ||
-       (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
+    if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
        return NSS_STATUS_UNAVAIL;
 
     nip = nss_group_nonlocal_database();
@@ -290,6 +329,11 @@ _nss_nonlocal_getgrnam_r(const char *name, struct group *grp,
     if (status != NSS_STATUS_SUCCESS)
        return status;
 
+    if (strcmp(name, grp->gr_name) != 0) {
+       syslog(LOG_ERR, "nss_nonlocal: discarding group %s from lookup for group %s\n", grp->gr_name, name);
+       return NSS_STATUS_NOTFOUND;
+    }
+
     return check_nonlocal_gid(name, grp->gr_gid, errnop);
 }
 
@@ -308,8 +352,7 @@ _nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
     } fct;
 
     char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
-    if (buflen == MAGIC_LOCAL_GR_BUFLEN ||
-       (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
+    if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
        return NSS_STATUS_UNAVAIL;
 
     nip = nss_group_nonlocal_database();
@@ -351,59 +394,47 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
     struct group local_users_group, nonlocal_users_group;
     gid_t local_users_gid, gid;
     int is_local = 0;
-    int buflen;
     char *buffer;
+    int old_errno;
+    int in, out, i;
 
     /* Check that the user is a nonlocal user before adding any groups. */
     status = check_nonlocal_user(user, errnop);
-    if (status == NSS_STATUS_NOTFOUND)
-       is_local = 1;
-    else if (status != NSS_STATUS_SUCCESS)
+    if (status == NSS_STATUS_TRYAGAIN)
        return status;
+    else if (status != NSS_STATUS_SUCCESS)
+       is_local = 1;
 
-    int old_errno = errno;
+    old_errno = errno;
 
-    buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
-    buffer = malloc(buflen);
-    if (buffer == NULL) {
-       *errnop = ENOMEM;
-       errno = old_errno;
-       return NSS_STATUS_TRYAGAIN;
-    }
     status = get_local_group(MAGIC_LOCAL_GROUPNAME,
-                            &local_users_group, buffer, buflen, errnop);
-    if (status == NSS_STATUS_NOTFOUND) {
+                            &local_users_group, &buffer, errnop);
+    if (status == NSS_STATUS_SUCCESS) {
+       local_users_gid = local_users_group.gr_gid;
+       free(buffer);
+    } else if (status == NSS_STATUS_TRYAGAIN) {
+       return status;
+    } else {
        syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
               MAGIC_LOCAL_GROUPNAME);
        local_users_gid = -1;
-    } else if (status != NSS_STATUS_SUCCESS) {
-       return status;
-    } else
-       local_users_gid = local_users_group.gr_gid;
-    free(buffer);
+    }
 
     if (is_local) {
        gid = local_users_gid;
     } else {
-       buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
-       buffer = malloc(buflen);
-       if (buffer == NULL) {
-           *errnop = ENOMEM;
-           errno = old_errno;
-           return NSS_STATUS_TRYAGAIN;
-       }
        status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
-                                &nonlocal_users_group, buffer, buflen, errnop);
-       if (status == NSS_STATUS_NOTFOUND) {
+                                &nonlocal_users_group, &buffer, errnop);
+       if (status == NSS_STATUS_SUCCESS) {
+           gid = nonlocal_users_group.gr_gid;
+           free(buffer);
+       } else if (status == NSS_STATUS_TRYAGAIN) {
+           return status;
+       } else {
            syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
                   MAGIC_NONLOCAL_GROUPNAME);
            gid = -1;
-       } else if (status != NSS_STATUS_SUCCESS) {
-           errno = old_errno;
-           return status;
-       } else
-           gid = nonlocal_users_group.gr_gid;
-       free(buffer);
+       }
     }
 
     if (gid != -1) {
@@ -421,7 +452,7 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
                    if (newsize > limit)
                        newsize = limit;
                }
-               newgroups = realloc(*groupsp, *size * sizeof((*groupsp)[0]));
+               newgroups = realloc(*groupsp, newsize * sizeof((*groupsp)[0]));
                if (newgroups == NULL) {
                    *errnop = ENOMEM;
                    errno = old_errno;
@@ -434,12 +465,10 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
        }
     }
 
-    errno = old_errno;
-
     if (is_local)
        return NSS_STATUS_SUCCESS;
 
-    int in = *start, out = *start, i;
+    in = out = *start;
 
     nip = nss_group_nonlocal_database();
     if (nip == NULL)
@@ -478,7 +507,7 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
        status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
        if (status == NSS_STATUS_SUCCESS) {
            (*groupsp)[out++] = (*groupsp)[in];
-       } else if (status != NSS_STATUS_NOTFOUND) {
+       } else if (status == NSS_STATUS_TRYAGAIN) {
            *start = out;
            *errnop = nonlocal_errno;
            return status;
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