From 9d26dfcbab62746b3e66ec7784d75c13ff499669 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Thu, 17 Jan 2019 13:36:43 -0600 Subject: [PATCH] nbd/server: Favor [u]int64_t over off_t Although our compile-time environment is set up so that we always support long files with 64-bit off_t, we have no guarantee whether off_t is the same type as int64_t. This requires casts when printing values, and prevents us from directly using qemu_strtoi64() (which will be done in the next patch). Let's just flip to uint64_t where possible, and stick to int64_t for detecting failure of blk_getlength(); we also keep the assertions added in the previous patch that the resulting values fit in 63 bits. The overflow check in nbd_co_receive_request() was already sane (request->from is validated to fit in 63 bits, and request->len is 32 bits, so the addition can't overflow 64 bits), but rewrite it in a form easier to recognize as a typical overflow check. Rename the variable 'description' to keep line lengths reasonable. Suggested-by: Vladimir Sementsov-Ogievskiy Signed-off-by: Eric Blake Message-Id: <20190117193658.16413-7-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy --- include/block/nbd.h | 4 ++-- nbd/server.c | 18 +++++++++--------- qemu-nbd.c | 29 +++++++++++------------------ 3 files changed, 22 insertions(+), 29 deletions(-) diff --git a/include/block/nbd.h b/include/block/nbd.h index 1971b55789..24be9570bb 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -294,8 +294,8 @@ int nbd_errno_to_system_errno(int err); typedef struct NBDExport NBDExport; typedef struct NBDClient NBDClient; -NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size, - const char *name, const char *description, +NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset, + uint64_t size, const char *name, const char *desc, const char *bitmap, uint16_t nbdflags, void (*close)(NBDExport *), bool writethrough, BlockBackend *on_eject_blk, Error **errp); diff --git a/nbd/server.c b/nbd/server.c index 51ee8094e0..cb0d5634fa 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -77,8 +77,8 @@ struct NBDExport { BlockBackend *blk; char *name; char *description; - off_t dev_offset; - off_t size; + uint64_t dev_offset; + uint64_t size; uint16_t nbdflags; QTAILQ_HEAD(, NBDClient) clients; QTAILQ_ENTRY(NBDExport) next; @@ -1455,8 +1455,8 @@ static void nbd_eject_notifier(Notifier *n, void *data) nbd_export_close(exp); } -NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size, - const char *name, const char *description, +NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset, + uint64_t size, const char *name, const char *desc, const char *bitmap, uint16_t nbdflags, void (*close)(NBDExport *), bool writethrough, BlockBackend *on_eject_blk, Error **errp) @@ -1495,12 +1495,12 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size, exp->refcount = 1; QTAILQ_INIT(&exp->clients); exp->blk = blk; - assert(dev_offset >= 0 && dev_offset <= INT64_MAX); + assert(dev_offset <= INT64_MAX); exp->dev_offset = dev_offset; exp->name = g_strdup(name); - exp->description = g_strdup(description); + exp->description = g_strdup(desc); exp->nbdflags = nbdflags; - assert(size >= 0 && size <= INT64_MAX - dev_offset); + assert(size <= INT64_MAX - dev_offset); exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE); if (bitmap) { @@ -2130,10 +2130,10 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, return -EROFS; } if (request->from > client->exp->size || - request->from + request->len > client->exp->size) { + request->len > client->exp->size - request->from) { error_setg(errp, "operation past EOF; From: %" PRIu64 ", Len: %" PRIu32 ", Size: %" PRIu64, request->from, request->len, - (uint64_t)client->exp->size); + client->exp->size); return (request->type == NBD_CMD_WRITE || request->type == NBD_CMD_WRITE_ZEROES) ? -ENOSPC : -EINVAL; } diff --git a/qemu-nbd.c b/qemu-nbd.c index 5c90c5e55f..598caa656b 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -176,7 +176,7 @@ static void read_partition(uint8_t *p, struct partition_record *r) } static int find_partition(BlockBackend *blk, int partition, - off_t *offset, off_t *size) + uint64_t *offset, uint64_t *size) { struct partition_record mbr[4]; uint8_t data[MBR_SIZE]; @@ -500,14 +500,14 @@ int main(int argc, char **argv) { BlockBackend *blk; BlockDriverState *bs; - off_t dev_offset = 0; + uint64_t dev_offset = 0; uint16_t nbdflags = 0; bool disconnect = false; const char *bindto = NULL; const char *port = NULL; char *sockpath = NULL; char *device = NULL; - off_t fd_size; + int64_t fd_size; QemuOpts *sn_opts = NULL; const char *sn_id_or_name = NULL; const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:B:"; @@ -665,10 +665,6 @@ int main(int argc, char **argv) error_report("Invalid offset `%s'", optarg); exit(EXIT_FAILURE); } - if (dev_offset < 0) { - error_report("Offset must be positive `%s'", optarg); - exit(EXIT_FAILURE); - } break; case 'l': if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) { @@ -1005,15 +1001,14 @@ int main(int argc, char **argv) } if (dev_offset >= fd_size) { - error_report("Offset (%lld) has to be smaller than the image size " - "(%lld)", - (long long int)dev_offset, (long long int)fd_size); + error_report("Offset (%" PRIu64 ") has to be smaller than the image " + "size (%" PRId64 ")", dev_offset, fd_size); exit(EXIT_FAILURE); } fd_size -= dev_offset; if (partition != -1) { - off_t limit; + uint64_t limit; if (dev_offset) { error_report("Cannot request partition and offset together"); @@ -1027,15 +1022,13 @@ int main(int argc, char **argv) } /* * MBR partition limits are (32-bit << 9); this assert lets - * the compiler know that we have two positive values that - * can't overflow 64 bits. + * the compiler know that we can't overflow 64 bits. */ - assert(dev_offset >= 0 && dev_offset + limit >= dev_offset); + assert(dev_offset + limit >= dev_offset); if (dev_offset + limit > fd_size) { - error_report("Discovered partition %d at offset %lld size %lld, " - "but size exceeds file length %lld", partition, - (long long int) dev_offset, (long long int) limit, - (long long int) fd_size); + error_report("Discovered partition %d at offset %" PRIu64 + " size %" PRIu64 ", but size exceeds file length %" + PRId64, partition, dev_offset, limit, fd_size); exit(EXIT_FAILURE); } fd_size = limit;