From 2d43d3273a40ea0fc7af2fd90212c9fa13f3b100 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Juhani=20Krekel=C3=A4?= Date: Wed, 10 Jul 2019 13:38:40 +0300 Subject: [PATCH] Remove unnecessary errno = 0; --- arp-request.c | 11 ----------- ethermess.c | 28 ---------------------------- ethertype-dump.c | 11 ----------- 3 files changed, 50 deletions(-) diff --git a/arp-request.c b/arp-request.c index 89ccf9b..dca51d0 100644 --- a/arp-request.c +++ b/arp-request.c @@ -2,7 +2,6 @@ #include #include #include -#include #include #include #include @@ -21,11 +20,9 @@ void drop_privileges(void) { uid_t uid = getuid(); gid_t gid = getgid(); - errno = 0; if (setresgid(gid, gid, gid) == -1) { err(1, "setresgid"); } - errno = 0; if (setresuid(uid, uid, uid) == -1) { err(1, "setresuid"); } @@ -41,7 +38,6 @@ int main(int argc, char **argv) { const char *target_ip = argv[2]; // Create a packet socket - errno = 0; int packet_socket = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); if (packet_socket == -1) { err(1, "socket"); @@ -53,7 +49,6 @@ int main(int argc, char **argv) { // Find the index of the network interface struct ifreq ifr; strncpy(ifr.ifr_name, interface_name, IFNAMSIZ); - errno = 0; if (ioctl(packet_socket, SIOCGIFINDEX, &ifr) == -1) { err(1, "ioctl"); } @@ -63,7 +58,6 @@ int main(int argc, char **argv) { sll.sll_family = AF_PACKET; sll.sll_protocol = htons(ETH_P_ALL); sll.sll_ifindex = ifr.ifr_ifindex; - errno = 0; if (bind(packet_socket, (const struct sockaddr*)&sll, sizeof(sll)) == -1) { err(1, "bind"); } @@ -96,7 +90,6 @@ int main(int argc, char **argv) { memset(&frame[0], 0xff, 6); // Source MAC - errno = 0; strncpy(ifr.ifr_name, interface_name, IFNAMSIZ); if (ioctl(packet_socket, SIOCGIFHWADDR, &ifr) == -1) { err(1, "ioctl"); @@ -133,7 +126,6 @@ int main(int argc, char **argv) { memcpy(&frame[22], &frame[6], 6); // Sender protocol address - errno = 0; strncpy(ifr.ifr_name, interface_name, IFNAMSIZ); if (ioctl(packet_socket, SIOCGIFADDR, &ifr) == -1) { err(1, "ioctl"); @@ -150,20 +142,17 @@ int main(int argc, char **argv) { // Target protocol address memset(&sin, 0, sizeof(sin)); - errno = 0; if (inet_pton(AF_INET, target_ip, &sin.sin_addr) == -1) { err(1, "inet_pton"); } memcpy(&frame[38], &sin.sin_addr.s_addr, 4); // Send the frame - errno = 0; if (write(packet_socket, frame, sizeof(frame)) != sizeof(frame)) { err(1, "write"); } // Close the socket (tho I'm not 100% sure it's needed) - errno = 0; if (close(packet_socket) == -1) { err(1, "close"); } diff --git a/ethermess.c b/ethermess.c index 6894c58..7f17916 100644 --- a/ethermess.c +++ b/ethermess.c @@ -2,7 +2,6 @@ #include #include #include -#include #include #include #include @@ -106,7 +105,6 @@ ssize_t msgid_cache_add(const unsigned char mac[6]) { unsigned char random_byte(void) { unsigned char randomness; - errno = 0; if (read(urandom, &randomness, 1) != 1) { err(1, "read"); } @@ -115,7 +113,6 @@ unsigned char random_byte(void) { time_t monotonic_time(void) { struct timespec now; - errno = 0; if (clock_gettime(CLOCK_MONOTONIC, &now) == -1) { err(1, "clock_gettime"); } @@ -141,18 +138,15 @@ void drop_privileges(void) { uid_t uid = getuid(); gid_t gid = getgid(); - errno = 0; if (setresgid(gid, gid, gid) == -1) { err(1, "setresgid"); } - errno = 0; if (setresuid(uid, uid, uid) == -1) { err(1, "setresuid"); } } void send_frame(const unsigned char *frame, size_t frame_length) { - errno = 0; if (write(packet_socket, frame, frame_length) == -1) { err(1, "write"); } @@ -281,7 +275,6 @@ void send_ack(const unsigned char destination[6], uint16_t msgid) { } void read_command(void) { - errno = 0; int cmd = getchar(); if (cmd == EOF) { err(1, "getchar"); @@ -362,12 +355,10 @@ void handle_status(const unsigned char source_mac[6], const unsigned char *data, char mac[18]; format_mac(source_mac, mac); - errno = 0; if (printf("%s status: ", mac) == -1) { err(1, "printf"); } - errno = 0; if (status == EMS_UNAVAILABLE) { if (printf("(unavailable) ") == -1) { err(1, "printf"); @@ -379,18 +370,15 @@ void handle_status(const unsigned char source_mac[6], const unsigned char *data, } for (size_t i = 0; i < (size_t)nick_length; i++) { - errno = 0; if (putchar(nick[i]) == EOF) { err(1, "putchar"); } } - errno = 0; if (putchar('\n') == EOF) { err(1, "putchar"); } - errno = 0; if (fflush(stdout) == EOF) { err(1, "fflush"); } @@ -422,12 +410,10 @@ void handle_msgid(const unsigned char source_mac[6], const unsigned char *data, char mac[18]; format_mac(source_mac, mac); - errno = 0; if (printf("%s awaits message ID %" PRIu16 "\n", mac, msgid_cache[cache_index].next_send) == 0) { err(1, "printf"); } - errno = 0; if (fflush(stdout) == EOF) { err(1, "fflush"); } @@ -465,24 +451,20 @@ void handle_message(const unsigned char source_mac[6], const unsigned char *data char mac[18]; format_mac(source_mac, mac); - errno = 0; if (printf("%s (%" PRIu16 "): ", mac, msgid) == -1) { err(1, "printf"); } for (size_t i = 0; i < message_length; i++) { - errno = 0; if (putchar(message[i]) == EOF) { err(1, "putchar"); } } - errno = 0; if (putchar('\n') == EOF) { err(1, "putchar"); } - errno = 0; if (fflush(stdout) == EOF) { err(1, "fflush"); } @@ -507,7 +489,6 @@ void handle_ack(const unsigned char source_mac[6], const unsigned char *data, si char mac[18]; format_mac(source_mac, mac); - errno = 0; if (printf("%s ack %" PRIu16 "\n", mac, msgid) == -1) { err(1, "printf"); } @@ -520,7 +501,6 @@ void handle_ack(const unsigned char source_mac[6], const unsigned char *data, si void process_frame(void) { unsigned char frame[1518]; // Largest a 802.3 frame can be without FCS - errno = 0; ssize_t res = recv(packet_socket, frame, sizeof(frame), 0); if (res == -1) { err(1, "recv"); @@ -650,7 +630,6 @@ void eventloop(void) { } } - errno = 0; int ready = poll(pollfds, sizeof(pollfds) / sizeof(*pollfds), wait_ms); if (ready == -1) { err(1, "poll"); @@ -698,7 +677,6 @@ int main(int argc, char **argv) { urandom = open("/dev/urandom", O_RDONLY); // Create a packet socket - errno = 0; packet_socket = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); if (packet_socket == -1) { err(1, "socket"); @@ -710,7 +688,6 @@ int main(int argc, char **argv) { // Find the index of the network interface struct ifreq ifr; strncpy(ifr.ifr_name, interface_name, IFNAMSIZ); - errno = 0; if (ioctl(packet_socket, SIOCGIFINDEX, &ifr) == -1) { err(1, "ioctl"); } @@ -720,13 +697,11 @@ int main(int argc, char **argv) { sll.sll_family = AF_PACKET; sll.sll_protocol = htons(ETH_P_ALL); sll.sll_ifindex = ifr.ifr_ifindex; - errno = 0; if (bind(packet_socket, (const struct sockaddr*)&sll, sizeof(sll)) == -1) { err(1, "bind"); } // Get our own MAC - errno = 0; strncpy(ifr.ifr_name, interface_name, IFNAMSIZ); if (ioctl(packet_socket, SIOCGIFHWADDR, &ifr) == -1) { err(1, "ioctl"); @@ -766,19 +741,16 @@ int main(int argc, char **argv) { eventloop(); // Close the socket (tho I'm not 100% sure it's needed) - errno = 0; if (close(packet_socket) == -1) { err(1, "close"); } // Flush stdout - errno = 0; if (fflush(stdout) == EOF) { err(1, "fflush"); } // Close urandom - errno = 0; if (close(urandom) == -1) { err(1, "close"); } diff --git a/ethertype-dump.c b/ethertype-dump.c index 1f2bc89..7abe5ab 100644 --- a/ethertype-dump.c +++ b/ethertype-dump.c @@ -2,7 +2,6 @@ #include #include #include -#include #include #include #include @@ -35,11 +34,9 @@ void drop_privileges(void) { uid_t uid = getuid(); gid_t gid = getgid(); - errno = 0; if (setresgid(gid, gid, gid) == -1) { err(1, "setresgid"); } - errno = 0; if (setresuid(uid, uid, uid) == -1) { err(1, "setresuid"); } @@ -52,7 +49,6 @@ int main(int argc, char **argv) { } // Create a packet socket - errno = 0; int packet_socket = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); if (packet_socket == -1) { err(1, "socket"); @@ -64,7 +60,6 @@ int main(int argc, char **argv) { // Find the index of the network interface struct ifreq ifr; strncpy(ifr.ifr_name, argv[1], IFNAMSIZ); - errno = 0; if (ioctl(packet_socket, SIOCGIFINDEX, &ifr) == -1) { err(1, "ioctl"); } @@ -74,7 +69,6 @@ int main(int argc, char **argv) { sll.sll_family = AF_PACKET; sll.sll_protocol = htons(ETH_P_ALL); sll.sll_ifindex = ifr.ifr_ifindex; - errno = 0; if (bind(packet_socket, (const struct sockaddr*)&sll, sizeof(sll)) == -1) { err(1, "bind"); } @@ -86,7 +80,6 @@ int main(int argc, char **argv) { err(1, "fflush"); } - errno = 0; ssize_t frame_length = recv(packet_socket, frame, sizeof(frame), MSG_TRUNC); if (frame_length == -1) { err(1, "recv"); @@ -95,7 +88,6 @@ int main(int argc, char **argv) { frame_length += 4; // Include the FCS in the true length if (frame_data_length < 14) { - errno = 0; if (printf("Frame too short to contain header (%zdB)\n", frame_length) == -1) { err(1, "printf"); } @@ -128,12 +120,10 @@ int main(int argc, char **argv) { ethertype_meaning = "IPv6"; } - errno = 0; if(printf("%s -> %s ethertype: %04" PRIx16, source_mac, destination_mac, ethertype) == -1) { err(1, "printf"); } - errno = 0; if (ethertype_meaning == NULL) { if (printf(", length: %zd", frame_length) == -1) { err(1, "printf"); @@ -144,7 +134,6 @@ int main(int argc, char **argv) { } } - errno = 0; if ((size_t)frame_length > sizeof(frame) + 4) { // +4 for the FCS if (printf(" (overlong)\n") == -1) { err(1, "printf");