Attachment 136757 Details for Bug 103737 – sysdeps: Get complete group vector from Linux SO_PEERGROUPS if possible

[patch] sysdeps: Get complete group vector from Linux SO_PEERGROUPS if possible

0002-sysdeps-Get-complete-group-vector-from-Linux-SO_PEER.patch (text/plain), 14.77 KB, created by Simon McVittie on 2018-01-16 13:48:39 UTC

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Creator: Simon McVittie

Created: 2018-01-16 13:48:39 UTC

Size: 14.77 KB

patch

obsolete

>From 31012b2712f814b97aff9bacf5d79904bbe0e327 Mon Sep 17 00:00:00 2001
>From: Simon McVittie <smcv@collabora.com>
>Date: Mon, 15 Jan 2018 19:44:45 +0000
>Subject: [PATCH 02/11] sysdeps: Get complete group vector from Linux
> SO_PEERGROUPS if possible
>
>Signed-off-by: Simon McVittie <smcv@collabora.com>
>---
> dbus/dbus-auth.c         |   5 ++
> dbus/dbus-credentials.c  | 109 ++++++++++++++++++++++++++++++++++++++++
> dbus/dbus-credentials.h  |   9 ++++
> dbus/dbus-sysdeps-unix.c | 126 +++++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 249 insertions(+)
>
>diff --git a/dbus/dbus-auth.c b/dbus/dbus-auth.c
>index 3182026c..0b886739 100644
>--- a/dbus/dbus-auth.c
>+++ b/dbus/dbus-auth.c
>@@ -1165,6 +1165,11 @@ handle_server_data_external_mech (DBusAuth         *auth,
>                                              auth->credentials))
>         return FALSE;
> 
>+      if (!_dbus_credentials_add_credential (auth->authorized_identity,
>+                                             DBUS_CREDENTIAL_UNIX_GROUP_IDS,
>+                                             auth->credentials))
>+        return FALSE;
>+
>       if (!_dbus_credentials_add_credential (auth->authorized_identity,
>                                              DBUS_CREDENTIAL_LINUX_SECURITY_LABEL,
>                                              auth->credentials))
>diff --git a/dbus/dbus-credentials.c b/dbus/dbus-credentials.c
>index 5fa754c2..5b585f37 100644
>--- a/dbus/dbus-credentials.c
>+++ b/dbus/dbus-credentials.c
>@@ -21,6 +21,7 @@
>  *
>  */
> #include <config.h>
>+#include <stdlib.h>
> #include <string.h>
> #include "dbus-credentials.h"
> #include "dbus-internals.h"
>@@ -48,6 +49,8 @@
> struct DBusCredentials {
>   int refcount;
>   dbus_uid_t unix_uid;
>+  dbus_gid_t *unix_gids;
>+  int n_unix_gids;
>   dbus_pid_t pid;
>   char *windows_sid;
>   char *linux_security_label;
>@@ -78,6 +81,8 @@ _dbus_credentials_new (void)
>   
>   creds->refcount = 1;
>   creds->unix_uid = DBUS_UID_UNSET;
>+  creds->unix_gids = NULL;
>+  creds->n_unix_gids = 0;
>   creds->pid = DBUS_PID_UNSET;
>   creds->windows_sid = NULL;
>   creds->linux_security_label = NULL;
>@@ -134,6 +139,7 @@ _dbus_credentials_unref (DBusCredentials    *credentials)
>   credentials->refcount -= 1;
>   if (credentials->refcount == 0)
>     {
>+      dbus_free (credentials->unix_gids);
>       dbus_free (credentials->windows_sid);
>       dbus_free (credentials->linux_security_label);
>       dbus_free (credentials->adt_audit_data);
>@@ -172,6 +178,63 @@ _dbus_credentials_add_unix_uid(DBusCredentials    *credentials,
> 
> }
> 
>+static int
>+cmp_gidp (const void *a_, const void *b_)
>+{
>+  const gid_t *a = a_;
>+  const gid_t *b = b_;
>+
>+  if (*a < *b)
>+    return -1;
>+
>+  if (*a > *b)
>+    return 1;
>+
>+  return 0;
>+}
>+
>+/**
>+ * Add UNIX group IDs to the credentials, replacing any group IDs that
>+ * might already have been present.
>+ *
>+ * @param credentials the object
>+ * @param gids the group IDs, which will be freed by the DBusCredentials object
>+ * @param n_gids the number of group IDs
>+ */
>+void
>+_dbus_credentials_take_unix_gids (DBusCredentials *credentials,
>+                                  dbus_gid_t      *gids,
>+                                  int              n_gids)
>+{
>+  /* So we can compare arrays via a simple memcmp */
>+  qsort (gids, n_gids, sizeof (dbus_gid_t), cmp_gidp);
>+
>+  dbus_free (credentials->unix_gids);
>+  credentials->unix_gids = gids;
>+  credentials->n_unix_gids = n_gids;
>+}
>+
>+/**
>+ * Get the Unix group IDs.
>+ *
>+ * @param credentials the object
>+ * @param gids the group IDs, which will be freed by the DBusCredentials object
>+ * @param n_gids the number of group IDs
>+ */
>+dbus_bool_t
>+_dbus_credentials_get_unix_gids (DBusCredentials   *credentials,
>+                                 const dbus_gid_t **gids,
>+                                 int               *n_gids)
>+{
>+  if (gids != NULL)
>+    *gids = credentials->unix_gids;
>+
>+  if (n_gids != NULL)
>+    *n_gids = credentials->n_unix_gids;
>+
>+  return (credentials->unix_gids != NULL);
>+}
>+
> /**
>  * Add a Windows user SID to the credentials.
>  *
>@@ -261,6 +324,8 @@ _dbus_credentials_include (DBusCredentials    *credentials,
>       return credentials->pid != DBUS_PID_UNSET;
>     case DBUS_CREDENTIAL_UNIX_USER_ID:
>       return credentials->unix_uid != DBUS_UID_UNSET;
>+    case DBUS_CREDENTIAL_UNIX_GROUP_IDS:
>+      return credentials->unix_gids != NULL;
>     case DBUS_CREDENTIAL_WINDOWS_SID:
>       return credentials->windows_sid != NULL;
>     case DBUS_CREDENTIAL_LINUX_SECURITY_LABEL:
>@@ -368,6 +433,10 @@ _dbus_credentials_are_superset (DBusCredentials    *credentials,
>      possible_subset->pid == credentials->pid) &&
>     (possible_subset->unix_uid == DBUS_UID_UNSET ||
>      possible_subset->unix_uid == credentials->unix_uid) &&
>+    (possible_subset->unix_gids == NULL ||
>+     (possible_subset->n_unix_gids == credentials->n_unix_gids &&
>+      memcmp (possible_subset->unix_gids, credentials->unix_gids,
>+              sizeof (dbus_gid_t) * credentials->n_unix_gids) == 0)) &&
>     (possible_subset->windows_sid == NULL ||
>      (credentials->windows_sid && strcmp (possible_subset->windows_sid,
>                                           credentials->windows_sid) == 0)) &&
>@@ -393,6 +462,8 @@ _dbus_credentials_are_empty (DBusCredentials    *credentials)
>   return
>     credentials->pid == DBUS_PID_UNSET &&
>     credentials->unix_uid == DBUS_UID_UNSET &&
>+    credentials->unix_gids == NULL &&
>+    credentials->n_unix_gids == 0 &&
>     credentials->windows_sid == NULL &&
>     credentials->linux_security_label == NULL &&
>     credentials->adt_audit_data == NULL;
>@@ -431,6 +502,9 @@ _dbus_credentials_add_credentials (DBusCredentials    *credentials,
>     _dbus_credentials_add_credential (credentials,
>                                       DBUS_CREDENTIAL_UNIX_USER_ID,
>                                       other_credentials) &&
>+    _dbus_credentials_add_credential (credentials,
>+                                      DBUS_CREDENTIAL_UNIX_GROUP_IDS,
>+                                      other_credentials) &&
>     _dbus_credentials_add_credential (credentials,
>                                       DBUS_CREDENTIAL_ADT_AUDIT_DATA_ID,
>                                       other_credentials) &&
>@@ -471,6 +545,22 @@ _dbus_credentials_add_credential (DBusCredentials    *credentials,
>       if (!_dbus_credentials_add_unix_uid (credentials, other_credentials->unix_uid))
>         return FALSE;
>     }
>+  else if (which == DBUS_CREDENTIAL_UNIX_GROUP_IDS &&
>+           other_credentials->unix_gids != NULL)
>+    {
>+      dbus_gid_t *gids;
>+
>+      gids = dbus_new (dbus_gid_t, other_credentials->n_unix_gids);
>+
>+      if (gids == NULL)
>+        return FALSE;
>+
>+      memcpy (gids, other_credentials->unix_gids,
>+              sizeof (dbus_gid_t) * other_credentials->n_unix_gids);
>+
>+      _dbus_credentials_take_unix_gids (credentials, gids,
>+                                        other_credentials->n_unix_gids);
>+    }
>   else if (which == DBUS_CREDENTIAL_WINDOWS_SID &&
>            other_credentials->windows_sid != NULL)
>     {
>@@ -504,6 +594,9 @@ _dbus_credentials_clear (DBusCredentials    *credentials)
> {
>   credentials->pid = DBUS_PID_UNSET;
>   credentials->unix_uid = DBUS_UID_UNSET;
>+  dbus_free (credentials->unix_gids);
>+  credentials->unix_gids = NULL;
>+  credentials->n_unix_gids = 0;
>   dbus_free (credentials->windows_sid);
>   credentials->windows_sid = NULL;
>   dbus_free (credentials->linux_security_label);
>@@ -590,6 +683,22 @@ _dbus_credentials_to_string_append (DBusCredentials    *credentials,
>     }
>   else
>     join = FALSE;
>+
>+  if (credentials->unix_gids != NULL)
>+    {
>+      int i;
>+
>+      for (i = 0; i < credentials->n_unix_gids; i++)
>+        {
>+          if (!_dbus_string_append_printf (string, "%sgid=" DBUS_GID_FORMAT,
>+                                           join ? " " : "",
>+                                           credentials->unix_gids[i]))
>+            goto oom;
>+
>+          join = TRUE;
>+        }
>+    }
>+
>   if (credentials->windows_sid != NULL)
>     {
>       if (!_dbus_string_append_printf (string, "%ssid=%s", join ? " " : "", credentials->windows_sid))
>diff --git a/dbus/dbus-credentials.h b/dbus/dbus-credentials.h
>index 6bf6c2b1..d44acb5d 100644
>--- a/dbus/dbus-credentials.h
>+++ b/dbus/dbus-credentials.h
>@@ -33,6 +33,7 @@ DBUS_BEGIN_DECLS
> typedef enum {
>   DBUS_CREDENTIAL_UNIX_PROCESS_ID,
>   DBUS_CREDENTIAL_UNIX_USER_ID,
>+  DBUS_CREDENTIAL_UNIX_GROUP_IDS,
>   DBUS_CREDENTIAL_ADT_AUDIT_DATA_ID,
>   DBUS_CREDENTIAL_LINUX_SECURITY_LABEL,
>   DBUS_CREDENTIAL_WINDOWS_SID
>@@ -53,6 +54,10 @@ DBUS_PRIVATE_EXPORT
> dbus_bool_t      _dbus_credentials_add_unix_uid             (DBusCredentials    *credentials,
>                                                              dbus_uid_t          uid);
> DBUS_PRIVATE_EXPORT
>+void             _dbus_credentials_take_unix_gids           (DBusCredentials    *credentials,
>+                                                             dbus_gid_t         *gids,
>+                                                             int                 n_gids);
>+DBUS_PRIVATE_EXPORT
> dbus_bool_t      _dbus_credentials_add_windows_sid          (DBusCredentials    *credentials,
>                                                              const char         *windows_sid);
> dbus_bool_t      _dbus_credentials_add_linux_security_label (DBusCredentials    *credentials,
>@@ -68,6 +73,10 @@ dbus_pid_t       _dbus_credentials_get_pid                  (DBusCredentials
> DBUS_PRIVATE_EXPORT
> dbus_uid_t       _dbus_credentials_get_unix_uid             (DBusCredentials    *credentials);
> DBUS_PRIVATE_EXPORT
>+dbus_bool_t      _dbus_credentials_get_unix_gids            (DBusCredentials    *credentials,
>+                                                             const dbus_gid_t  **gids,
>+                                                             int                *n_gids);
>+DBUS_PRIVATE_EXPORT
> const char*      _dbus_credentials_get_windows_sid          (DBusCredentials    *credentials);
> const char *     _dbus_credentials_get_linux_security_label (DBusCredentials    *credentials);
> void *           _dbus_credentials_get_adt_audit_data       (DBusCredentials    *credentials);
>diff --git a/dbus/dbus-sysdeps-unix.c b/dbus/dbus-sysdeps-unix.c
>index 9f859845..0f1a16db 100644
>--- a/dbus/dbus-sysdeps-unix.c
>+++ b/dbus/dbus-sysdeps-unix.c
>@@ -1748,6 +1748,116 @@ write_credentials_byte (int             server_fd,
>     }
> }
> 
>+/* return FALSE on OOM, TRUE otherwise, even if no groups were found */
>+static dbus_bool_t
>+add_groups_to_credentials (int              client_fd,
>+                           DBusCredentials *credentials,
>+                           dbus_gid_t       primary)
>+{
>+#if defined(__linux__) && defined(SO_PEERGROUPS)
>+  _DBUS_STATIC_ASSERT (sizeof (gid_t) <= sizeof (dbus_gid_t));
>+  gid_t *buf = NULL;
>+  socklen_t len = 1024;
>+  dbus_bool_t oom = FALSE;
>+  /* libdbus has a different representation of group IDs just to annoy you */
>+  dbus_gid_t *converted_gids = NULL;
>+  dbus_bool_t need_primary = TRUE;
>+  size_t n_gids;
>+  size_t i;
>+
>+  n_gids = ((size_t) len) / sizeof (gid_t);
>+  buf = dbus_new (gid_t, n_gids);
>+
>+  if (buf == NULL)
>+    return FALSE;
>+
>+  while (getsockopt (client_fd, SOL_SOCKET, SO_PEERGROUPS, buf, &len) < 0)
>+    {
>+      int e = errno;
>+      gid_t *replacement;
>+
>+      _dbus_verbose ("getsockopt failed with %s, len now %lu\n",
>+                     _dbus_strerror (e), (unsigned long) len);
>+
>+      if (e != ERANGE || (size_t) len <= n_gids * sizeof (gid_t))
>+        {
>+          _dbus_verbose ("Failed to getsockopt(SO_PEERGROUPS): %s\n",
>+                         _dbus_strerror (e));
>+          goto out;
>+        }
>+
>+      /* If not enough space, len is updated to be enough.
>+       * Try again with a large enough buffer. */
>+      n_gids = ((size_t) len) / sizeof (gid_t);
>+      replacement = dbus_realloc (buf, len);
>+
>+      if (replacement == NULL)
>+        {
>+          oom = TRUE;
>+          goto out;
>+        }
>+
>+      buf = replacement;
>+      _dbus_verbose ("will try again with %lu\n", (unsigned long) len);
>+    }
>+
>+  if (len <= 0)
>+    {
>+      _dbus_verbose ("getsockopt(SO_PEERGROUPS) yielded <= 0 bytes: %ld\n",
>+                     (long) len);
>+      goto out;
>+    }
>+
>+  if (len > n_gids * sizeof (gid_t))
>+    {
>+      _dbus_verbose ("%lu > %zu", (unsigned long) len, n_gids * sizeof (gid_t));
>+      _dbus_assert_not_reached ("getsockopt(SO_PEERGROUPS) overflowed");
>+    }
>+
>+  if (len % sizeof (gid_t) != 0)
>+    {
>+      _dbus_verbose ("getsockopt(SO_PEERGROUPS) did not return an "
>+                     "integer multiple of sizeof(gid_t): %lu should be "
>+                     "divisible by %zu",
>+                     (unsigned long) len, sizeof (gid_t));
>+      goto out;
>+    }
>+
>+  /* Allocate an extra space for the primary group ID */
>+  n_gids = ((size_t) len) / sizeof (gid_t);
>+  converted_gids = dbus_new (dbus_gid_t, n_gids + 1);
>+
>+  if (converted_gids == 0)
>+    {
>+      oom = TRUE;
>+      goto out;
>+    }
>+
>+  for (i = 0; i < n_gids; i++)
>+    {
>+      converted_gids[i] = (dbus_gid_t) buf[i];
>+
>+      if (converted_gids[i] == primary)
>+        need_primary = FALSE;
>+    }
>+
>+  if (need_primary && primary != DBUS_GID_UNSET)
>+    {
>+      converted_gids[n_gids] = primary;
>+      n_gids++;
>+    }
>+
>+  _dbus_credentials_take_unix_gids (credentials, converted_gids, n_gids);
>+
>+out:
>+  dbus_free (buf);
>+  return !oom;
>+#else
>+  /* no error */
>+  return TRUE;
>+#endif
>+}
>+
> /* return FALSE on OOM, TRUE otherwise, even if no credentials were found */
> static dbus_bool_t
> add_linux_security_label_to_credentials (int              client_fd,
>@@ -1896,6 +2006,7 @@ _dbus_read_credentials_socket  (DBusSocket       client_fd,
>   struct iovec iov;
>   char buf;
>   dbus_uid_t uid_read;
>+  dbus_gid_t primary_gid_read;
>   dbus_pid_t pid_read;
>   int bytes_read;
> 
>@@ -1915,6 +2026,7 @@ _dbus_read_credentials_socket  (DBusSocket       client_fd,
>   _DBUS_STATIC_ASSERT (sizeof (gid_t) <= sizeof (dbus_gid_t));
> 
>   uid_read = DBUS_UID_UNSET;
>+  primary_gid_read = DBUS_GID_UNSET;
>   pid_read = DBUS_PID_UNSET;
> 
>   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
>@@ -2001,6 +2113,12 @@ _dbus_read_credentials_socket  (DBusSocket       client_fd,
>       {
>         pid_read = cr.pid;
>         uid_read = cr.uid;
>+#ifdef __linux__
>+        /* Do other platforms have cr.gid? (Not that it really matters,
>+         * because the gid is useless to us unless we know the complete
>+         * group vector, which we only know on Linux.) */
>+        primary_gid_read = cr.gid;
>+#endif
>       }
> #elif defined(HAVE_UNPCBID) && defined(LOCAL_PEEREID)
>     /* Another variant of the above - used on NetBSD
>@@ -2181,6 +2299,14 @@ _dbus_read_credentials_socket  (DBusSocket       client_fd,
>       return FALSE;
>     }
> 
>+  /* We don't put any groups in the credentials unless we can put them
>+   * all there. */
>+  if (!add_groups_to_credentials (client_fd.fd, credentials, primary_gid_read))
>+    {
>+      _DBUS_SET_OOM (error);
>+      return FALSE;
>+    }
>+
>   return TRUE;
> }
> 
>-- 
>2.15.1
>

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Attachments on bug 103737: 136756 | 136757 | 136758 | 136759 | 136760 | 136762 | 136763 | 136764 | 136766 | 136767 | 136768 | 136770 | 137397 | 137398 | 137399 | 137400 | 138213 | 138221

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