util: command: Extract common parts of FD closing to virCommandMassClose

Extract the lookup of used FDs and their setup to virCommandMassClose
rather than duplicate it in the two functions we have for using
different modes of FD closing.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/src/util/vircommand.c b/src/util/vircommand.c
index e871d572a66a94096989a2c401b2197c0328f88c..2d13cf629cb350ed47a3e589a2d8c66a9a48db65 100644 (file)
--- a/src/util/vircommand.c
+++ b/src/util/vircommand.c
@@ -520,16 +520,12 @@ virCommandMassCloseGetFDs(virBitmap *fds)
 }
 
 static int
-virCommandMassCloseFrom(virCommand *cmd,
-                        int childin,
-                        int childout,
-                        int childerr)
+virCommandMassCloseFrom(virBitmap *keep)
 {
     g_autoptr(virBitmap) fds = NULL;
     int openmax = sysconf(_SC_OPEN_MAX);
-    int lastfd = -1;
+    int lastfd = virBitmapLastSetBit(keep);
     int fd = -1;
-    size_t i;
 
     /* In general, it is not safe to call malloc() between fork() and exec()
      * because the child might have forked at the worst possible time, i.e.
@@ -551,24 +547,14 @@ virCommandMassCloseFrom(virCommand *cmd,
     if (virCommandMassCloseGetFDs(fds) < 0)
         return -1;
 
-    lastfd = MAX(lastfd, childin);
-    lastfd = MAX(lastfd, childout);
-    lastfd = MAX(lastfd, childerr);
-
-    for (i = 0; i < cmd->npassfd; i++)
-        lastfd = MAX(lastfd, cmd->passfd[i].fd);
-
     fd = virBitmapNextSetBit(fds, 2);
     for (; fd >= 0 && fd <= lastfd; fd = virBitmapNextSetBit(fds, fd)) {
-        if (fd == childin || fd == childout || fd == childerr)
+        int tmpfd = fd;
+
+        if (virBitmapIsBitSet(keep, fd))
             continue;
-        if (!virCommandFDIsSet(cmd, fd)) {
-            int tmpfd = fd;
-            VIR_MASS_CLOSE(tmpfd);
-        } else if (virSetInherit(fd, true) < 0) {
-            virReportSystemError(errno, _("failed to preserve fd %1$d"), fd);
-            return -1;
-        }
+
+        VIR_MASS_CLOSE(tmpfd);
     }
 
     if (virCloseFrom(lastfd + 1) < 0) {
@@ -588,33 +574,13 @@ virCommandMassCloseFrom(virCommand *cmd,
 
 
 static int
-virCommandMassCloseRange(virCommand *cmd,
-                         int childin,
-                         int childout,
-                         int childerr)
+virCommandMassCloseRange(virBitmap *keep)
 {
-    g_autoptr(virBitmap) fds = virBitmapNew(0);
     ssize_t first;
     ssize_t last;
-    size_t i;
-
-    virBitmapSetBitExpand(fds, childin);
-    virBitmapSetBitExpand(fds, childout);
-    virBitmapSetBitExpand(fds, childerr);
-
-    for (i = 0; i < cmd->npassfd; i++) {
-        int fd = cmd->passfd[i].fd;
-
-        virBitmapSetBitExpand(fds, fd);
-
-        if (virSetInherit(fd, true) < 0) {
-            virReportSystemError(errno, _("failed to preserve fd %1$d"), fd);
-            return -1;
-        }
-    }
 
     first = 2;
-    while ((last = virBitmapNextSetBit(fds, first)) >= 0) {
+    while ((last = virBitmapNextSetBit(keep, first)) >= 0) {
         if (first + 1 == last) {
             first = last;
             continue;
@@ -642,17 +608,44 @@ virCommandMassCloseRange(virCommand *cmd,
 }
 
 
-
+/**
+ * virCommandMassClose:
+ * @cmd: command structure
+ * @childin: fd passed to child as stdin
+ * @childout: fd passed to child as stdout
+ * @childerr: fd passed to child as stderr
+ *
+ * Prepares FDs to be passed to the child process spawned by @cmd and closes
+ * every other FD.
+ */
 static int
 virCommandMassClose(virCommand *cmd,
                     int childin,
                     int childout,
                     int childerr)
 {
+    g_autoptr(virBitmap) fds = virBitmapNew(0);
+    size_t i;
+
+    virBitmapSetBitExpand(fds, childin);
+    virBitmapSetBitExpand(fds, childout);
+    virBitmapSetBitExpand(fds, childerr);
+
+    for (i = 0; i < cmd->npassfd; i++) {
+        int fd = cmd->passfd[i].fd;
+
+        virBitmapSetBitExpand(fds, fd);
+
+        if (virSetInherit(fd, true) < 0) {
+            virReportSystemError(errno, _("failed to preserve fd %1$d"), fd);
+            return -1;
+        }
+    }
+
     if (virCloseRangeIsSupported())
-        return virCommandMassCloseRange(cmd, childin, childout, childerr);
+        return virCommandMassCloseRange(fds);
 
-    return virCommandMassCloseFrom(cmd, childin, childout, childerr);
+    return virCommandMassCloseFrom(fds);
 }