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authorPaolo Bonzini <pbonzini@redhat.com>2011-09-19 16:04:36 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2011-12-22 11:53:58 +0100
commitfae69416294223d84db425e58e7bbf6a08c45801 (patch)
tree51e65888f3321a3a01aa3196a2a712d41b358071 /nbd.c
parent220455920384af77670e84953f3763153e39bcfa (diff)
downloadqemu-arm-fae69416294223d84db425e58e7bbf6a08c45801.tar.gz
qemu-nbd: more robust handling of invalid requests
Fail invalid requests with EINVAL instead of dropping them into the void. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'nbd.c')
-rw-r--r--nbd.c57
1 files changed, 30 insertions, 27 deletions
diff --git a/nbd.c b/nbd.c
index 025c5b0f1d..053ad8d00d 100644
--- a/nbd.c
+++ b/nbd.c
@@ -624,18 +624,19 @@ int nbd_trip(BlockDriverState *bs, int csock, off_t size,
if (nbd_receive_request(csock, &request) == -1)
return -1;
+ reply.handle = request.handle;
+ reply.error = 0;
+
if (request.len > NBD_BUFFER_SIZE) {
LOG("len (%u) is larger than max len (%u)",
request.len, NBD_BUFFER_SIZE);
- errno = EINVAL;
- return -1;
+ goto invalid_request;
}
if ((request.from + request.len) < request.from) {
LOG("integer overflow detected! "
"you're probably being attacked");
- errno = EINVAL;
- return -1;
+ goto invalid_request;
}
if ((request.from + request.len) > size) {
@@ -643,15 +644,11 @@ int nbd_trip(BlockDriverState *bs, int csock, off_t size,
", Offset: %" PRIu64 "\n",
request.from, request.len, (uint64_t)size, dev_offset);
LOG("requested operation past EOF--bad client?");
- errno = EINVAL;
- return -1;
+ goto invalid_request;
}
TRACE("Decoding type");
- reply.handle = request.handle;
- reply.error = 0;
-
switch (request.type & NBD_CMD_MASK_COMMAND) {
case NBD_CMD_READ:
TRACE("Request type is READ");
@@ -661,7 +658,7 @@ int nbd_trip(BlockDriverState *bs, int csock, off_t size,
if (ret < 0) {
LOG("reading from file failed");
reply.error = -ret;
- request.len = 0;
+ goto error_reply;
}
TRACE("Read %u byte(s)", request.len);
@@ -681,24 +678,26 @@ int nbd_trip(BlockDriverState *bs, int csock, off_t size,
if (nbdflags & NBD_FLAG_READ_ONLY) {
TRACE("Server is read-only, return error");
- reply.error = 1;
- } else {
- TRACE("Writing to device");
+ reply.error = EROFS;
+ goto error_reply;
+ }
+
+ TRACE("Writing to device");
+
+ ret = bdrv_write(bs, (request.from + dev_offset) / 512,
+ data, request.len / 512);
+ if (ret < 0) {
+ LOG("writing to file failed");
+ reply.error = -ret;
+ goto error_reply;
+ }
- ret = bdrv_write(bs, (request.from + dev_offset) / 512,
- data, request.len / 512);
+ if (request.type & NBD_CMD_FLAG_FUA) {
+ ret = bdrv_flush(bs);
if (ret < 0) {
- LOG("writing to file failed");
+ LOG("flush failed");
reply.error = -ret;
- request.len = 0;
- }
-
- if (request.type & NBD_CMD_FLAG_FUA) {
- ret = bdrv_flush(bs);
- if (ret < 0) {
- LOG("flush failed");
- reply.error = -ret;
- }
+ goto error_reply;
}
}
@@ -734,8 +733,12 @@ int nbd_trip(BlockDriverState *bs, int csock, off_t size,
break;
default:
LOG("invalid request type (%u) received", request.type);
- errno = EINVAL;
- return -1;
+ invalid_request:
+ reply.error = -EINVAL;
+ error_reply:
+ if (nbd_do_send_reply(csock, &reply, NULL, 0) == -1)
+ return -1;
+ break;
}
TRACE("Request/Reply complete");