From ce254c58b8a9e7a3e69ede931a588555756b7c12 Mon Sep 17 00:00:00 2001
From: Juan Quintela <quintela@redhat.com>
Date: Tue, 28 Jul 2015 15:46:54 +0200
Subject: [PATCH 09/28] Add qemu_get_counted_string to read a string prefixed
by a count byte
Message-id: <1438098431-30847-10-git-send-email-quintela@redhat.com>
Patchwork-id: 67166
O-Subject: [RHEL-7 qemu-kvm PATCH 09/26] Add qemu_get_counted_string to read a string prefixed by a count byte
Bugzilla: 580006
RH-Acked-by: Alex Williamson <alex.williamson@redhat.com>
RH-Acked-by: Amit Shah <amit.shah@redhat.com>
RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
and use it in loadvm_state and ram_load.
Where ever it's used, check the return and error if it failed.
Minor: ram_load was using a 257 byte array for its string, the
maximum length is 255 bytes + 0 terminator, so fix to 256
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
(cherry picked from commit b3af1bc9d21e6bec7dfd283d91b465c9f815b6d6)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
Conflicts:
migration/qemu-file.c
compression code
Signed-off-by: Juan Quintela <quintela@trasno.org>
---
include/migration/qemu-file.h | 3 +++
migration/qemu-file.c | 18 ++++++++++++++++++
migration/savevm.c | 11 ++++++-----
3 files changed, 27 insertions(+), 5 deletions(-)
diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h
index a3ceb3b..b7f8a99 100644
--- a/include/migration/qemu-file.h
+++ b/include/migration/qemu-file.h
@@ -313,4 +313,7 @@ static inline void qemu_get_sbe64s(QEMUFile *f, int64_t *pv)
{
qemu_get_be64s(f, (uint64_t *)pv);
}
+
+size_t qemu_get_counted_string(QEMUFile *f, char buf[256]);
+
#endif
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index eadfc93..af045c2 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -552,3 +552,21 @@ uint64_t qemu_get_be64(QEMUFile *f)
v |= qemu_get_be32(f);
return v;
}
+
+/*
+ * Get a string whose length is determined by a single preceding byte
+ * A preallocated 256 byte buffer must be passed in.
+ * Returns: len on success and a 0 terminated string in the buffer
+ * else 0
+ * (Note a 0 length string will return 0 either way)
+ */
+size_t qemu_get_counted_string(QEMUFile *f, char buf[256])
+{
+ size_t len = qemu_get_byte(f);
+ size_t res = qemu_get_buffer(f, (uint8_t *)buf, len);
+
+ buf[res] = 0;
+
+ return res == len ? res : 0;
+}
+
diff --git a/migration/savevm.c b/migration/savevm.c
index 9279875..044d8ad 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1035,8 +1035,7 @@ int qemu_loadvm_state(QEMUFile *f)
while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
uint32_t instance_id, version_id, section_id;
SaveStateEntry *se;
- char idstr[257];
- int len;
+ char idstr[256];
trace_qemu_loadvm_state_section(section_type);
switch (section_type) {
@@ -1044,9 +1043,11 @@ int qemu_loadvm_state(QEMUFile *f)
case QEMU_VM_SECTION_FULL:
/* Read section start */
section_id = qemu_get_be32(f);
- len = qemu_get_byte(f);
- qemu_get_buffer(f, (uint8_t *)idstr, len);
- idstr[len] = 0;
+ if (!qemu_get_counted_string(f, idstr)) {
+ error_report("Unable to read ID string for section %u",
+ section_id);
+ return -EINVAL;
+ }
instance_id = qemu_get_be32(f);
version_id = qemu_get_be32(f);
--
1.8.3.1