icmp_interface_send(), icmp_interface_read() and icmp_interface_filter() return the raw syscall results. On failure this is -1 while the callers interpret negative values as negative errno codes: ping and traceroute print strerror(-res) and thus always report "Operation not permitted" no matter why the send, receive or filter setup actually failed (for example ENETDOWN when the interface goes down mid-ping or ENOMEM when attaching the socket filter). The other error paths of these functions already return proper negative errno values.
Convert the syscall failures to -errno before returning them. Signed-off-by: Sven Eckelmann <[email protected]> --- icmp_helper.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/icmp_helper.c b/icmp_helper.c index 15bae9a..65a2005 100644 --- a/icmp_helper.c +++ b/icmp_helper.c @@ -154,7 +154,7 @@ static int icmp_interface_filter(int sock, int uid) if (setsockopt(sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter))) - return -1; + return -errno; return 0; } @@ -348,6 +348,7 @@ static int icmp_interface_send(struct batadv_icmp_header *icmp_packet, { struct ether_header header; struct iovec vector[2]; + ssize_t ret; header.ether_type = htons(ETH_P_BATMAN); memcpy(header.ether_shost, iface->mac, ETH_ALEN); @@ -358,7 +359,11 @@ static int icmp_interface_send(struct batadv_icmp_header *icmp_packet, vector[1].iov_base = icmp_packet; vector[1].iov_len = packet_len; - return (int)writev(iface->sock, vector, 2); + ret = writev(iface->sock, vector, 2); + if (ret < 0) + return -errno; + + return (int)ret; } int icmp_interface_write(struct state *state, @@ -494,9 +499,12 @@ ssize_t icmp_interface_read(struct batadv_icmp_header *icmp_packet, size_t len, max_sock = icmp_interface_preselect(&read_sockets); res = select(max_sock, &read_sockets, NULL, NULL, tv); - /* timeout, or < 0 error */ - if (res <= 0) - return res; + if (res < 0) + return -errno; + + /* timeout */ + if (res == 0) + return 0; read_sock = icmp_interface_get_read_sock(&read_sockets, &iface); if (read_sock < 0) @@ -509,7 +517,7 @@ ssize_t icmp_interface_read(struct batadv_icmp_header *icmp_packet, size_t len, read_len = readv(read_sock, vector, 2); if (read_len < 0) - return read_len; + return -errno; if (read_len < ETH_HLEN) goto retry; -- 2.47.3
