After read, file offset must be set to 0 before write.
Otherwise, the third byte will be overwritten instead of the first.
Fixes: c6fd54f28c24 ("kni: add function to set link state on kernel interface")
Cc: sta...@dpdk.org
Signed-off-by: Igor Ryzhov <iryz...@nfware.com>
---
lib/librte_kni/rte_kni.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/lib/librte_kni/rte_kni.c b/lib/librte_kni/rte_kni.c
index 73aeccccf..5899bb14a 100644
--- a/lib/librte_kni/rte_kni.c
+++ b/lib/librte_kni/rte_kni.c
@@ -746,6 +746,12 @@ rte_kni_update_link(struct rte_kni *kni, unsigned int
linkup)
}
old_linkup = (old_carrier[0] == '1');
+ if (lseek(fd, 0, SEEK_SET) == -1) {
+ RTE_LOG(ERR, KNI, "Failed to change file position: %s.\n",
path);
+ close(fd);
+ return -1;
+ }
+
new_carrier = linkup ? "1" : "0";
ret = write(fd, new_carrier, 1);
if (ret < 1) {
--
2.20.1
