1 files changed, 135 insertions, 0 deletions
diff --git a/repo/hooks/acl.sh b/repo/hooks/acl.sh
new file mode 100755
index 00000000..859e5e2c
--- /dev/null
+++ b/repo/hooks/acl.sh
@@ -0,0 +1,135 @@
+#!/bin/bash
+
+umask 002
+
+# If you are having trouble with this access control hook script
+# you can try setting this to true.  It will tell you exactly
+# why a user is being allowed/denied access.
+
+verbose=true
+
+# Default shell globbing messes things up downstream
+GLOBIGNORE=*
+
+function grant {
+  $verbose && echo >&2 "-Grant-		$1"
+  echo grant
+  exit 0
+}
+
+function deny {
+  $verbose && echo >&2 "-Deny-		$1"
+  echo deny
+  exit 1
+}
+
+function info {
+  $verbose && echo >&2 "-Info-		$1"
+}
+
+# Implement generic branch and tag policies.
+# - Tags should not be updated once created.
+# - Branches should only be fast-forwarded unless their pattern starts with '+'
+case "$1" in
+  refs/tags/*)
+    git rev-parse --verify -q "$1" &&
+    deny >/dev/null "You can't overwrite an existing tag"
+    ;;
+  refs/heads/*)
+    # No rebasing or rewinding
+    if expr "$2" : '0*$' >/dev/null; then
+      info "The branch '$1' is new..."
+    else
+      # updating -- make sure it is a fast forward
+      mb=$(git-merge-base "$2" "$3")
+      case "$mb,$2" in
+        "$2,$mb") info "Update is fast-forward" ;;
+	*)	  noff=y; info "This is not a fast-forward update.";;
+      esac
+    fi
+    ;;
+  *)
+    deny >/dev/null \
+    "Branch is not under refs/heads or refs/tags.  What are you trying to do?"
+    ;;
+esac
+
+# Implement per-branch controls based on username
+allowed_users_file=$GIT_DIR/info/allowed-users
+username=$(id -u -n)
+info "The user is: '$username'"
+
+if test -f "$allowed_users_file"
+then
+  rc=$(cat $allowed_users_file | grep -v '^#' | grep -v '^$' |
+    while read heads user_patterns
+    do
+      # does this rule apply to us?
+      head_pattern=${heads#+}
+      matchlen=$(expr "$1" : "${head_pattern#+}")
+      test "$matchlen" = ${#1} || continue
+
+      # if non-ff, $heads must be with the '+' prefix
+      test -n "$noff" &&
+      test "$head_pattern" = "$heads" && continue
+
+      info "Found matching head pattern: '$head_pattern'"
+      for user_pattern in $user_patterns; do
+	info "Checking user: '$username' against pattern: '$user_pattern'"
+	matchlen=$(expr "$username" : "$user_pattern")
+	if test "$matchlen" = "${#username}"
+	then
+	  grant "Allowing user: '$username' with pattern: '$user_pattern'"
+	fi
+      done
+      deny "The user is not in the access list for this branch"
+    done
+  )
+  case "$rc" in
+    grant) grant >/dev/null "Granting access based on $allowed_users_file" ;;
+    deny)  deny  >/dev/null "Denying  access based on $allowed_users_file" ;;
+    *) ;;
+  esac
+fi
+
+allowed_groups_file=$GIT_DIR/info/allowed-groups
+groups=$(id -G -n)
+info "The user belongs to the following groups:"
+info "'$groups'"
+
+if test -f "$allowed_groups_file"
+then
+  rc=$(cat $allowed_groups_file | grep -v '^#' | grep -v '^$' |
+    while read heads group_patterns
+    do
+      # does this rule apply to us?
+      head_pattern=${heads#+}
+      matchlen=$(expr "$1" : "${head_pattern#+}")
+      test "$matchlen" = ${#1} || continue
+
+      # if non-ff, $heads must be with the '+' prefix
+      test -n "$noff" &&
+      test "$head_pattern" = "$heads" && continue
+
+      info "Found matching head pattern: '$head_pattern'"
+      for group_pattern in $group_patterns; do
+	for groupname in $groups; do
+	  info "Checking group: '$groupname' against pattern: '$group_pattern'"
+	  matchlen=$(expr "$groupname" : "$group_pattern")
+	  if test "$matchlen" = "${#groupname}"
+	  then
+	    grant "Allowing group: '$groupname' with pattern: '$group_pattern'"
+	  fi
+        done
+      done
+      deny "None of the user's groups are in the access list for this branch"
+    done
+  )
+  case "$rc" in
+    grant) grant >/dev/null "Granting access based on $allowed_groups_file" ;;
+    deny)  deny  >/dev/null "Denying  access based on $allowed_groups_file" ;;
+    *) ;;
+  esac
+fi
+
+deny >/dev/null "There are no more rules to check.  Denying access"