qemu-kvm/SOURCES/kvm-virtiofsd-add-fuse_mbuf_iter-API.patch

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From 1b0edd3d0a2ee5c097bcf3501c1dfa937f02e473 Mon Sep 17 00:00:00 2001
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Date: Mon, 27 Jan 2020 19:01:21 +0100
Subject: [PATCH 050/116] virtiofsd: add fuse_mbuf_iter API
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: <20200127190227.40942-47-dgilbert@redhat.com>
Patchwork-id: 93502
O-Subject: [RHEL-AV-8.2 qemu-kvm PATCH 046/112] virtiofsd: add fuse_mbuf_iter API
Bugzilla: 1694164
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Sergio Lopez Pascual <slp@redhat.com>
From: Stefan Hajnoczi <stefanha@redhat.com>
Introduce an API for consuming bytes from a buffer with size checks.
All FUSE operations will be converted to use this safe API instead of
void *inarg.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
(cherry picked from commit dad157e880416ab3a0e45beaa0e81977516568bc)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
tools/virtiofsd/buffer.c | 28 +++++++++++++++++++++++++
tools/virtiofsd/fuse_common.h | 49 ++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 76 insertions(+), 1 deletion(-)
diff --git a/tools/virtiofsd/buffer.c b/tools/virtiofsd/buffer.c
index 772efa9..42a608f 100644
--- a/tools/virtiofsd/buffer.c
+++ b/tools/virtiofsd/buffer.c
@@ -267,3 +267,31 @@ ssize_t fuse_buf_copy(struct fuse_bufvec *dstv, struct fuse_bufvec *srcv)
return copied;
}
+
+void *fuse_mbuf_iter_advance(struct fuse_mbuf_iter *iter, size_t len)
+{
+ void *ptr;
+
+ if (len > iter->size - iter->pos) {
+ return NULL;
+ }
+
+ ptr = iter->mem + iter->pos;
+ iter->pos += len;
+ return ptr;
+}
+
+const char *fuse_mbuf_iter_advance_str(struct fuse_mbuf_iter *iter)
+{
+ const char *str = iter->mem + iter->pos;
+ size_t remaining = iter->size - iter->pos;
+ size_t i;
+
+ for (i = 0; i < remaining; i++) {
+ if (str[i] == '\0') {
+ iter->pos += i + 1;
+ return str;
+ }
+ }
+ return NULL;
+}
diff --git a/tools/virtiofsd/fuse_common.h b/tools/virtiofsd/fuse_common.h
index 0cb33ac..f8f6433 100644
--- a/tools/virtiofsd/fuse_common.h
+++ b/tools/virtiofsd/fuse_common.h
@@ -703,10 +703,57 @@ size_t fuse_buf_size(const struct fuse_bufvec *bufv);
*/
ssize_t fuse_buf_copy(struct fuse_bufvec *dst, struct fuse_bufvec *src);
+/**
+ * Memory buffer iterator
+ *
+ */
+struct fuse_mbuf_iter {
+ /**
+ * Data pointer
+ */
+ void *mem;
+
+ /**
+ * Total length, in bytes
+ */
+ size_t size;
+
+ /**
+ * Offset from start of buffer
+ */
+ size_t pos;
+};
+
+/* Initialize memory buffer iterator from a fuse_buf */
+#define FUSE_MBUF_ITER_INIT(fbuf) \
+ ((struct fuse_mbuf_iter){ \
+ .mem = fbuf->mem, \
+ .size = fbuf->size, \
+ .pos = 0, \
+ })
+
+/**
+ * Consume bytes from a memory buffer iterator
+ *
+ * @param iter memory buffer iterator
+ * @param len number of bytes to consume
+ * @return pointer to start of consumed bytes or
+ * NULL if advancing beyond end of buffer
+ */
+void *fuse_mbuf_iter_advance(struct fuse_mbuf_iter *iter, size_t len);
+
+/**
+ * Consume a NUL-terminated string from a memory buffer iterator
+ *
+ * @param iter memory buffer iterator
+ * @return pointer to the string or
+ * NULL if advancing beyond end of buffer or there is no NUL-terminator
+ */
+const char *fuse_mbuf_iter_advance_str(struct fuse_mbuf_iter *iter);
+
/*
* Signal handling
*/
-
/**
* Exit session on HUP, TERM and INT signals and ignore PIPE signal
*
--
1.8.3.1