[libvirt] [PATCH 1/3] utils: Implement virCommandPassFDGetFDIndex
Implement virCommandPassFDGetFDIndex to determine the index a given
file descriptor will have when passed to the child process. When this
function is called, a flag is set to prevent the reordering of the
file descriptors.
Signed-off-by: Stefan Berger <stefanb(a)linux.vnet.ibm.com>
---
src/libvirt_private.syms | 1 +
src/util/vircommand.c | 33 +++++++++++++++++++++++++++++++++
src/util/vircommand.h | 3 +++
3 files changed, 37 insertions(+)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index c156b40..aadb833 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1213,6 +1213,7 @@ virCommandNewArgList;
virCommandNewArgs;
virCommandNonblockingFDs;
virCommandPassFD;
+virCommandPassFDGetFDIndex;
virCommandPassListenFDs;
virCommandRawStatus;
virCommandRequireHandshake;
diff --git a/src/util/vircommand.c b/src/util/vircommand.c
index 6527d85..2616446 100644
--- a/src/util/vircommand.c
+++ b/src/util/vircommand.c
@@ -67,6 +67,7 @@ enum {
VIR_EXEC_RUN_SYNC = (1 << 3),
VIR_EXEC_ASYNC_IO = (1 << 4),
VIR_EXEC_LISTEN_FDS = (1 << 5),
+ VIR_EXEC_FIXED_FDS = (1 << 6),
};
typedef struct _virCommandFD virCommandFD;
@@ -214,6 +215,12 @@ virCommandReorderFDs(virCommandPtr cmd)
if (!cmd || cmd->has_error || !cmd->npassfd)
return;
+ if ((cmd->flags & VIR_EXEC_FIXED_FDS)) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("The fds are fixed and cannot be reordered"));
+ goto error;
+ }
+
for (i = 0; i < cmd->npassfd; i++)
maxfd = MAX(cmd->passfd[i].fd, maxfd);
@@ -1019,6 +1026,32 @@ virCommandPassListenFDs(virCommandPtr cmd)
cmd->flags |= VIR_EXEC_LISTEN_FDS;
}
+/*
+ * virCommandPassFDGetFDIndex:
+ * @cmd: pointer to virCommand
+ * @fd: FD to get index of
+ *
+ * Determine the index of the FD in the transfer set.
+ *
+ * Returns index >= 0 if @set contains @fd,
+ * -1 otherwise.
+ */
+int
+virCommandPassFDGetFDIndex(virCommandPtr cmd, int fd)
+{
+ size_t i = 0;
+
+ while (i < cmd->npassfd) {
+ if (cmd->passfd[i].fd == fd) {
+ cmd->flags |= VIR_EXEC_FIXED_FDS;
+ return i;
+ }
+ i++;
+ }
+
+ return -1;
+}
+
/**
* virCommandSetPidFile:
* @cmd: the command to modify
diff --git a/src/util/vircommand.h b/src/util/vircommand.h
index bf65de4..198da2f 100644
--- a/src/util/vircommand.h
+++ b/src/util/vircommand.h
@@ -62,6 +62,9 @@ void virCommandPassFD(virCommandPtr cmd,
void virCommandPassListenFDs(virCommandPtr cmd);
+int virCommandPassFDGetFDIndex(virCommandPtr cmd,
+ int fd);
+
void virCommandSetPidFile(virCommandPtr cmd,
const char *pidfile) ATTRIBUTE_NONNULL(2);
--
1.9.3