X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/58cadc8608fbb2cbc7b74578cd92de4337a4b887..37c817eb8159366539d4a9c69bd78e74d4941c06:/uidlist.c

diff --git a/uidlist.c b/uidlist.c
index d8a7af11..38c265b3 100644
--- a/uidlist.c
+++ b/uidlist.c
@@ -25,6 +25,13 @@
 
 #include "rsync.h"
 
+#ifdef GETGROUPS_T
+# ifndef NGROUPS_MAX
+/* It ought to be defined, but just in case. */
+#  define NGROUPS_MAX 32
+# endif
+#endif
+
 extern int preserve_uid;
 extern int preserve_gid;
 extern int numeric_ids;
@@ -71,7 +78,7 @@ static char *gid_to_name(gid_t gid)
 static int map_uid(int id, char *name)
 {
 	uid_t uid;
-	if (name_to_uid(name, &uid) && uid != 0)
+	if (uid != 0 && name_to_uid(name, &uid))
 		return uid;
 	return id;
 }
@@ -79,7 +86,7 @@ static int map_uid(int id, char *name)
 static int map_gid(int id, char *name)
 {
 	gid_t gid;
-	if (name_to_gid(name, &gid) && gid != 0)
+	if (gid != 0 && name_to_gid(name, &gid))
 		return gid;
 	return id;
 }
@@ -106,9 +113,52 @@ static uid_t match_uid(uid_t uid)
 	return last_out;
 }
 
+static int is_in_group(gid_t gid)
+{
+#ifdef GETGROUPS_T
+	static gid_t last_in = (gid_t) -2, last_out;
+	static int ngroups = -2;
+	static GETGROUPS_T *gidset;
+	int n;
+
+	if (gid == last_in)
+		return last_out;
+	if (ngroups < -1) {
+		gid_t mygid = getgid();
+		ngroups = getgroups(0, 0);
+		/* If that didn't work, perhaps 0 isn't treated specially? */
+		if (ngroups < 0)
+			ngroups = NGROUPS_MAX;
+		gidset = new_array(GETGROUPS_T, ngroups+1);
+		if (ngroups > 0)
+			ngroups = getgroups(ngroups, gidset);
+		/* The default gid might not be in the list on some systems. */
+		for (n = 0; n < ngroups; n++) {
+			if (gidset[n] == mygid)
+				break;
+		}
+		if (n == ngroups)
+			gidset[ngroups++] = mygid;
+	}
+
+	last_in = gid;
+	last_out = 0;
+	for (n = 0; n < ngroups; n++) {
+		if (gidset[n] == gid) {
+			last_out = 1;
+			break;
+		}
+	}
+	return last_out;
+
+#else
+	return 0;
+#endif
+}
+
 static gid_t match_gid(gid_t gid)
 {
-	static gid_t last_in, last_out;
+	static gid_t last_in = (gid_t) -2, last_out;
 	struct idlist *list = gidlist;
 
 	if (gid == last_in) return last_out;
@@ -126,7 +176,7 @@ static gid_t match_gid(gid_t gid)
 	if (am_root)
 		last_out = gid;
 	else
-		last_out = (gid_t) -1;
+		last_out = GID_NONE;
 	return last_out;
 }
 
@@ -238,8 +288,7 @@ void recv_uid_list(int f, struct file_list *flist)
 	if (preserve_uid) {
 		/* read the uid list */
 		list = uidlist;
-		id = read_int(f);
-		while (id != 0) {
+		while ((id = read_int(f)) != 0) {
 			int len = read_byte(f);
 			name = new_array(char, len+1);
 			if (!name) out_of_memory("recv_uid_list");
@@ -253,7 +302,6 @@ void recv_uid_list(int f, struct file_list *flist)
 			}
 			list->id2 = map_uid(id, name);
 			free(name);
-			id = read_int(f);
 		}
 	}
 
@@ -261,8 +309,7 @@ void recv_uid_list(int f, struct file_list *flist)
 	if (preserve_gid) {
 		/* and the gid list */
 		list = gidlist;
-		id = read_int(f);
-		while (id != 0) {
+		while ((id = read_int(f)) != 0) {
 			int len = read_byte(f);
 			name = new_array(char, len+1);
 			if (!name) out_of_memory("recv_uid_list");
@@ -275,8 +322,9 @@ void recv_uid_list(int f, struct file_list *flist)
 				list = list->next;
 			}
 			list->id2 = map_gid(id, name);
+			if (!am_root && !is_in_group(list->id2))
+				list->id2 = GID_NONE;
 			free(name);
-			id = read_int(f);
 		}
 	}
 
@@ -284,12 +332,10 @@ void recv_uid_list(int f, struct file_list *flist)
 
 	/* now convert the uid/gid of all files in the list to the mapped
 	   uid/gid */
-	for (i=0;i<flist->count;i++) {
-		if (am_root && preserve_uid && flist->files[i]->uid != 0) {
+	for (i = 0; i < flist->count; i++) {
+		if (am_root && preserve_uid && flist->files[i]->uid != 0)
 			flist->files[i]->uid = match_uid(flist->files[i]->uid);
-		}
-		if (preserve_gid && flist->files[i]->gid != 0) {
+		if (preserve_gid && (!am_root || flist->files[i]->gid != 0))
 			flist->files[i]->gid = match_gid(flist->files[i]->gid);
-		}
 	}
 }