Re: [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&gt; --- 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 -- libvir-list mailing list libvir-list(a)redhat.com https://www.redhat.com/mailman/listinfo/libvir-list