trafgen: reset errno before calling sscanf in str2mac

When testing trafgen with the following example from the man page the
error message "Failed to parse MAC address 11:22:33:44:55:66" is
printed.

  trafgen -o lo --cpus 1 -n 3 '{ eth(da=11:22:33:44:55:66, da[0]=dinc()), tcp() }'

Turns out errno was not cleared before str2mac() called sscanf().

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

1 files changed, 1 insertions, 0 deletions

diff --git a/str.c b/str.c
index 1d3e7ac..9ab94ca 100644
--- a/str.c
+++ b/str.c
@@ -143,6 +143,7 @@ int str2mac(const char *str, uint8_t *mac, size_t len)
 	if (len < 6)
 		return -ENOSPC;
 
+	errno = 0;
 	count = sscanf(str, "%02X:%02X:%02X:%02X:%02X:%02X",
 			&tmp[0], &tmp[1], &tmp[2], &tmp[3], &tmp[4], &tmp[5]);