Mark arguments as const as needed in C programs

This was already done in the libraries, but not in the programs.

TODO.t2t

@@ -47,9 +47,8 @@ Work to do in OwlPS
 
 - Mark arguments as const in function headers if needed
 
-  Mostly done in the Positioner C++ code (which should nonetheless be
+  Mostly done in the Positioner C++ code (to be checked).
-  checked), but not constantly in C modules.
+  //Done in lib* and other C modules.//
-  //Done in lib*.//
 
 - Use struct ether_addr to store MAC addresses?
 

libowlps-resultreader/libowlps-resultreader.c

@@ -474,7 +474,7 @@ void owl_algorithm_result_to_csv_simple
  * Prints an `owl_result` to the given stream, using `fprintf()`.
  * `src` must not be `NULL`.
  */
-void owl_fprint_result(FILE *stream, const owl_result *const src)
+void owl_fprint_result(FILE *const stream, const owl_result *const src)
 {
   char timestamp_str[OWL_TIMESTAMP_STRLEN] ;
 
@@ -506,7 +506,7 @@ void owl_fprint_result(FILE *stream, const owl_result *const src)
  * `fprintf()`.
  * `src` must not be `NULL`.
  */
-void owl_fprint_algorithm_result(FILE *stream,
+void owl_fprint_algorithm_result(FILE *const stream,
                                  const owl_algorithm_result *const src)
 {
   assert(src) ;

libowlps-resultreader/owlps-resultreader.h

@@ -135,9 +135,9 @@ void owl_algorithm_result_to_csv_simple
  const owl_algorithm_result *const src) ;
 
 /// Prints an `owl_result` to the given stream
-void owl_fprint_result(FILE *stream, const owl_result *const src) ;
+void owl_fprint_result(FILE *const stream, const owl_result *const src) ;
 /// Prints an `owl_algorithm_result` to the given stream
-void owl_fprint_algorithm_result(FILE *stream,
+void owl_fprint_algorithm_result(FILE *const stream,
                                  const owl_algorithm_result *const src) ;
 /// Prints an `owl_result` to the standard output
 #define owl_print_result(SRC) \

owlps-aggregator/owlps-aggregator.h

@@ -102,19 +102,19 @@ typedef struct _cp_list
 
 
 /* Function headers */
-int initialise_configuration(int argc, char **argv) ;
+int initialise_configuration(const int argc, char *const *argv) ;
-int parse_config_file(int argc, char **argv) ;
+int parse_config_file(const int argc, char *const *argv) ;
-int parse_command_line(int argc, char **argv) ;
+int parse_command_line(const int argc, char *const *argv) ;
 int check_configuration(void) ;
 
-int read_loop(int sockfd) ;
+int read_loop(const int sockfd) ;
 void print_captured_request(const owl_captured_request *const request) ;
 void got_request(const owl_captured_request *const request) ;
 void add_captured_request(const owl_timestamp *const reception_time,
                           const owl_captured_request *const request,
                           request_info_list *const request_info) ;
 
-void* monitor_requests(void *NULL_value) ;
+void* monitor_requests(void *const NULL_value) ;
 void scan_request_list(FILE *const stream,
                        const int sockfd,
                        const struct sockaddr *const serv) ;
@@ -128,23 +128,24 @@ void output_request(request_list *const request_ptr,
 
 #ifndef NDEBUG
 void print_request_list(void) ;
-void print_request_info(request_info_list *info) ;
+void print_request_info(const request_info_list *const info) ;
 #endif // NDEBUG
 
-void* listen_for_cps(void *NULL_value) ;
+void* listen_for_cps(void *const NULL_value) ;
-void update_cp(uint8_t mac_addr_bytes[ETHER_ADDR_LEN],
+void update_cp(const uint8_t mac_addr_bytes[ETHER_ADDR_LEN],
-               char ip_addr[INET_ADDRSTRLEN]) ;
+               const char ip_addr[INET_ADDRSTRLEN]) ;
-cp_list* find_cp(uint8_t mac_addr_bytes[ETHER_ADDR_LEN]) ;
+cp_list* find_cp(const uint8_t mac_addr_bytes[ETHER_ADDR_LEN]) ;
-cp_list* add_cp_front(uint8_t mac_addr_bytes[ETHER_ADDR_LEN]) ;
+cp_list* add_cp_front(const uint8_t mac_addr_bytes[ETHER_ADDR_LEN]) ;
-void update_cp_ip_addr(cp_list *cp, char ip_addr[INET_ADDRSTRLEN]) ;
+void update_cp_ip_addr(cp_list *const cp,
-void update_cp_seen(cp_list *cp) ;
+                       const char ip_addr[INET_ADDRSTRLEN]) ;
-void push_cp(cp_list *cp) ;
+void update_cp_seen(cp_list *const cp) ;
+void push_cp(cp_list *const cp) ;
 
-void* monitor_cps(void *NULL_value) ;
+void* monitor_cps(void *const NULL_value) ;
 void delete_old_cps(void) ;
-void delete_cp(cp_list *cp) ;
+void delete_cp(cp_list *const cp) ;
-void unlink_cp(cp_list *cp) ;
+void unlink_cp(const cp_list *const cp) ;
-void order_send(cp_list *cp) ;
+void order_send(const cp_list *const cp) ;
 void free_cp_list(void) ;
 
 void print_usage(void) ;

owlps-aggregator/owlps-aggregatord.c

@@ -55,7 +55,7 @@ sem_t lock_cps ; // Semaphore to get access to the CPs' ring
 
 
 
-int main(int argc, char **argv)
+int main(const int argc, char *const *argv)
 {
   int ret = 0 ; // Program return value
   struct sigaction action ; // Signal handler structure
@@ -199,7 +199,7 @@ int main(int argc, char **argv)
  * stop (because of a special option or a configuration error), owl_run
  * is set to false.
  */
-int initialise_configuration(int argc, char **argv)
+int initialise_configuration(const int argc, char *const *argv)
 {
   int ret ;
 
@@ -234,7 +234,7 @@ int initialise_configuration(int argc, char **argv)
 }
 
 
-int parse_config_file(int argc, char **argv)
+int parse_config_file(const int argc, char *const *argv)
 {
   // Config file options for confuse
   cfg_opt_t opts[] =
@@ -360,7 +360,7 @@ int parse_config_file(int argc, char **argv)
 }
 
 
-int parse_command_line(int argc, char **argv)
+int parse_command_line(const int argc, char *const *argv)
 {
   int opt ;
   long arg_long ; // Integer value of optarg
@@ -563,7 +563,7 @@ int check_configuration()
 /*
  * Reads packets while the program is not stopped.
  */
-int read_loop(int sockfd)
+int read_loop(const int sockfd)
 {
   int ret = 0 ; // Return value
   ssize_t nread ; // recvfrom return value
@@ -849,7 +849,7 @@ void add_captured_request(const owl_timestamp *const reception_time,
  * Thread function. Monitors the list and prints/sends information to the
  * localisation server when the timeout is reached.
  */
-void* monitor_requests(void *NULL_value)
+void* monitor_requests(void *const NULL_value)
 {
   FILE *stream = NULL ;
   struct sockaddr serv;
@@ -1180,7 +1180,7 @@ void print_request_list()
 /*
  * Prints an element of a request_info_list.
  */
-void print_request_info(request_info_list *info)
+void print_request_info(const request_info_list *const info)
 {
   char cp_mac_str[OWL_ETHER_ADDR_STRLEN] ;
   if (info == NULL)
@@ -1201,7 +1201,7 @@ void print_request_info(request_info_list *info)
 /*
  * Thread function. Listens for hello messages from CPs.
  */
-void* listen_for_cps(void *NULL_value)
+void* listen_for_cps(void *const NULL_value)
 {
   int listen_sockfd ;
   int nread ; // recvfrom return value
@@ -1258,8 +1258,8 @@ void* listen_for_cps(void *NULL_value)
  * Updates the timestamp of the CP with the given MAC address if it is in
  * the CP list, or add a new CP with this MAC address to the CP list.
  */
-void update_cp(uint8_t mac_addr_bytes[ETHER_ADDR_LEN],
+void update_cp(const uint8_t mac_addr_bytes[ETHER_ADDR_LEN],
-               char ip_addr[INET_ADDRSTRLEN])
+               const char ip_addr[INET_ADDRSTRLEN])
 {
   cp_list *found ;
 
@@ -1279,7 +1279,7 @@ void update_cp(uint8_t mac_addr_bytes[ETHER_ADDR_LEN],
  * Searches the CP list for a CP with the given MAC address and returns
  * it.
  */
-cp_list* find_cp(uint8_t mac_addr_bytes[ETHER_ADDR_LEN])
+cp_list* find_cp(const uint8_t mac_addr_bytes[ETHER_ADDR_LEN])
 {
   cp_list *found ;
 
@@ -1303,7 +1303,7 @@ cp_list* find_cp(uint8_t mac_addr_bytes[ETHER_ADDR_LEN])
  * Adds a new CP in front of the CP list.
  * Returns the new list head, or NULL in case of error.
  */
-cp_list* add_cp_front(uint8_t mac_addr_bytes[ETHER_ADDR_LEN])
+cp_list* add_cp_front(const uint8_t mac_addr_bytes[ETHER_ADDR_LEN])
 {
   if (VERBOSE_INFO)
     {
@@ -1330,7 +1330,8 @@ cp_list* add_cp_front(uint8_t mac_addr_bytes[ETHER_ADDR_LEN])
 /*
  * Change the IP address of the CP 'cp' with 'ip_addr'.
  */
-void update_cp_ip_addr(cp_list *cp, char ip_addr[INET_ADDRSTRLEN])
+void update_cp_ip_addr(cp_list *const cp,
+                       const char ip_addr[INET_ADDRSTRLEN])
 {
   strncpy(cp->ip_addr, ip_addr, INET_ADDRSTRLEN) ;
 }
@@ -1339,7 +1340,7 @@ void update_cp_ip_addr(cp_list *cp, char ip_addr[INET_ADDRSTRLEN])
 /*
  * Updates the timestamp of the given CP.
  */
-void update_cp_seen(cp_list *cp)
+void update_cp_seen(cp_list *const cp)
 {
   assert(cp) ;
   owl_timestamp_now(&cp->last_seen) ;
@@ -1350,7 +1351,7 @@ void update_cp_seen(cp_list *cp)
  * Puts an existing CP in front of the CP list. The CP must not be in
  * the list yet.
  */
-void push_cp(cp_list *cp)
+void push_cp(cp_list *const cp)
 {
   assert(cp) ;
 
@@ -1377,7 +1378,7 @@ void push_cp(cp_list *cp)
  * Monitors the CP list: sends orders to CPs following their order in
  * the list, and deletes old CPs.
  */
-void* monitor_cps(void *NULL_value)
+void* monitor_cps(void *const NULL_value)
 {
   if (VERBOSE_WARNING)
     fprintf(stderr, "Monitor CP thread launched.\n") ;
@@ -1429,7 +1430,7 @@ void delete_old_cps()
 /*
  * Deletes the given CP from the CP list.
  */
-void delete_cp(cp_list *cp)
+void delete_cp(cp_list *const cp)
 {
   if (VERBOSE_INFO)
     {
@@ -1448,7 +1449,7 @@ void delete_cp(cp_list *cp)
  * Extracts the given CP from the CP list (it will not be linked to any
  * other element of the list).
  */
-void unlink_cp(cp_list *cp)
+void unlink_cp(const cp_list *const cp)
 {
   cp_list
     *cp_previous,
@@ -1478,7 +1479,7 @@ void unlink_cp(cp_list *cp)
 /*
  * Sends a 'send' order to the given CP.
  */
-void order_send(cp_list *cp)
+void order_send(const cp_list *const cp)
 {
   owl_autocalibration_order message ;
   struct sockaddr serv;

owlps-client/owlps-client.c

@@ -55,17 +55,17 @@
 
 
 /* Function headers */
-void parse_command_line(int argc, char **argv) ;
+void parse_command_line(const int argc, char *const *argv) ;
-void parse_main_options(int argc, char **argv) ;
+void parse_main_options(const int argc, char *const *argv) ;
 void check_destination_host(void) ;
-void parse_calibration_data(int argc, char **argv) ;
+void parse_calibration_data(const int argc, char *const *argv) ;
 void check_configuration(void) ;
 void print_configuration(void) ;
 void create_socket(void) ;
 void send_request(void) ;
 void make_packet(void) ;
 void add_padding(void) ;
-uint_fast16_t initialise_common_fields(uint_fast8_t packet_type) ;
+uint_fast16_t initialise_common_fields(const uint_fast8_t packet_type) ;
 uint_fast16_t initialise_calibration_fields(uint_fast16_t offset) ;
 #ifdef OWLPS_CLIENT_RECEIVES_POSITION
 int receive_position(void) ;
@@ -209,7 +209,7 @@ int main(int argc, char *argv[])
 
 
 
-void parse_command_line(int argc, char **argv)
+void parse_command_line(const int argc, char *const *argv)
 {
   parse_main_options(argc, argv) ;
   check_destination_host() ;
@@ -222,7 +222,7 @@ void parse_command_line(int argc, char **argv)
 
 
 
-void parse_main_options(int argc, char **argv)
+void parse_main_options(const int argc, char *const *argv)
 {
   int opt ;
   long arg_long ; // Integer value of optarg
@@ -390,7 +390,7 @@ void check_destination_host()
 
 
 /* Parses remaining arguments (possible calibration data) */
-void parse_calibration_data(int argc, char **argv)
+void parse_calibration_data(const int argc, char *const *argv)
 {
   /* No more arguments to parse */
   if (argc - optind == 0)
@@ -679,7 +679,7 @@ void add_padding()
 /*
  * Initialises the fields of a normal positioning request.
  */
-uint_fast16_t initialise_common_fields(uint_fast8_t packet_type)
+uint_fast16_t initialise_common_fields(const uint_fast8_t packet_type)
 {
   uint_fast16_t offset = 0 ;
   uint16_t npkt ;

owlps-listener/owlps-listener.h

@@ -171,45 +171,46 @@ enum {MODE_ACTIVE = 'a', MODE_PASSIVE = 'p', MODE_MIXED = 'm'} ;
 
 
 /* Function headers */
-int initialise_configuration(int argc, char **argv) ;
+int initialise_configuration(const int argc, char *const *argv) ;
-int parse_config_file(int argc, char **argv) ;
+int parse_config_file(const int argc, char *const *argv) ;
-int parse_command_line(int argc, char **argv) ;
+int parse_command_line(const int argc, char *const *argv) ;
-int parse_main_options(int argc, char **argv) ;
+int parse_main_options(const int argc, char *const *argv) ;
 #ifdef OWLPS_LISTENER_USES_PTHREAD
-int parse_calibration_data(int argc, char **argv) ;
+int parse_calibration_data(const int argc, char *const *argv) ;
 #endif // OWLPS_LISTENER_USES_PTHREAD
 int check_configuration(void) ;
-void print_configuration(FILE *stream) ;
+void print_configuration(FILE *const stream) ;
 
 #ifdef OWLPS_LISTENER_KEEPS_MONITOR
-void* keep_mode_monitor(void *iface) ;
+void* keep_mode_monitor(const void *const iface) ;
 int iface_mode_monitor(const char *const iface) ;
 #endif // OWLPS_LISTENER_KEEPS_MONITOR
 int capture(void) ;
-void read_packet(const struct pcap_pkthdr *pkt_header,
+void read_packet(const struct pcap_pkthdr *const pkt_header,
-                 const u_char *pkt_data) ;
+                 const u_char *const pkt_data) ;
-void extract_calibration_data(const u_char *pkt_data,
+void extract_calibration_data(const u_char *const pkt_data,
-                              owl_captured_request *request) ;
+                              owl_captured_request *const request) ;
-void extract_packet_numbers(const u_char *pkt_data,
+void extract_packet_numbers(const u_char *const pkt_data,
-                            owl_captured_request *request) ;
+                            owl_captured_request *const request) ;
-bool extract_radiotap_ss(const u_char *pkt_data,
+bool extract_radiotap_ss(const u_char *const pkt_data,
-                         owl_captured_request *request) ;
+                         owl_captured_request *const request) ;
-uint_fast16_t nat_align(uint_fast16_t offset, uint_fast8_t field_len) ;
+uint_fast16_t nat_align(const uint_fast16_t offset,
-void display_captured_request(owl_captured_request *request,
+                        const  uint_fast8_t field_len) ;
-                              const struct pcap_pkthdr *pkt_header) ;
+void display_captured_request(const owl_captured_request *const request,
+                              const struct pcap_pkthdr *const pkt_header) ;
 void get_mac_addr(const char *const iface,
                   uint8_t mac_bytes[ETHER_ADDR_LEN]) ;
-void get_ip_addr(const char *const iface, char *ip_bytes) ;
+void get_ip_addr(const char *const iface, char ip[INET_ADDRSTRLEN]) ;
 
 #ifdef OWLPS_LISTENER_USES_PTHREAD
-void* autocalibrate(void *NULL_value) ;
+void* autocalibrate_hello(void *const NULL_value) ;
-void* autocalibrate_hello(void *NULL_value) ;
+void* autocalibrate(void *const NULL_value) ;
 void send_autocalibration_request(void) ;
-uint_fast16_t make_packet(uint8_t **packet) ;
+uint_fast16_t make_packet(uint8_t **const packet) ;
 #endif // OWLPS_LISTENER_USES_PTHREAD
 
-void sigint_handler(int num) ;
+void sigint_handler(const int num) ;
-void sigterm_handler(int num) ;
+void sigterm_handler(const int num) ;
 
 void print_usage(void) ;
 void print_version(void) ;

owlps-listener/owlps-listenerd.c

@@ -314,7 +314,7 @@ int main(int argc, char *argv[])
  * stop (because of a special option or a configuration error), owl_run
  * is set to false.
  */
-int initialise_configuration(int argc, char **argv)
+int initialise_configuration(const int argc, char *const *argv)
 {
   int ret ;
 
@@ -350,7 +350,7 @@ int initialise_configuration(int argc, char **argv)
 
 
 
-int parse_config_file(int argc, char **argv)
+int parse_config_file(const int argc, char *const *argv)
 {
 #ifdef OWLPS_LISTENER_USES_CONFIG_FILE
   // If we use libconfuse, we declare options:
@@ -507,7 +507,7 @@ int parse_config_file(int argc, char **argv)
 
 
 
-int parse_command_line(int argc, char **argv)
+int parse_command_line(const int argc, char *const *argv)
 {
   int ret ;
 
@@ -526,7 +526,7 @@ int parse_command_line(int argc, char **argv)
 
 
 
-int parse_main_options(int argc, char **argv)
+int parse_main_options(const int argc, char *const *argv)
 {
   int opt ;
   long arg_long ; // Integer value of optarg
@@ -654,7 +654,7 @@ int parse_main_options(int argc, char **argv)
 
 #ifdef OWLPS_LISTENER_USES_PTHREAD
 /* Parses remaining arguments (possible calibration data) */
-int parse_calibration_data(int argc, char **argv)
+int parse_calibration_data(const int argc, char *const *argv)
 {
   /* No more arguments to parse */
   if (argc - optind == 0)
@@ -865,7 +865,7 @@ int check_configuration()
 
 
 
-void print_configuration(FILE *stream)
+void print_configuration(FILE *const stream)
 {
 #ifdef OWLPS_LISTENER_USES_CONFIG_FILE
   cfg_print(cfg, stream) ;
@@ -931,7 +931,7 @@ void print_configuration(FILE *stream)
  * Thread function. Switches interface 'iface' to monitor mode every
  * second. `iface` must be passed as a const char *const.
  */
-void* keep_mode_monitor(void *iface)
+void* keep_mode_monitor(const void *const iface)
 {
   if (VERBOSE_WARNING)
     fprintf(stderr, "Thread for keeping monitor mode launched.\n") ;
@@ -1056,8 +1056,8 @@ int capture()
 /*
  * Treats a packet and sends it to the aggregator.
  */
-void read_packet(const struct pcap_pkthdr *pkt_header,
+void read_packet(const struct pcap_pkthdr *const pkt_header,
-                 const u_char *pkt_data)
+                 const u_char *const pkt_data)
 {
   owl_captured_request request ; // Message to send to the aggregator
   uint16_t rtap_bytes ; // Radiotap header size
@@ -1285,8 +1285,8 @@ void read_packet(const struct pcap_pkthdr *pkt_header,
  * Note: 'pkt_data' is read from its first byte, therefore you must not
  * pass the whole received packet to this function.
  */
-void extract_calibration_data(const u_char *pkt_data,
+void extract_calibration_data(const u_char *const pkt_data,
-                              owl_captured_request *request)
+                              owl_captured_request *const request)
 {
   request->direction = pkt_data[0] ;
   assert(sizeof(float) == 4) ;
@@ -1303,8 +1303,8 @@ void extract_calibration_data(const u_char *pkt_data,
  * Note: 'pkt_data' is read from its first byte, therefore you must not
  * pass the whole received packet to this function.
  */
-void extract_packet_numbers(const u_char *pkt_data,
+void extract_packet_numbers(const u_char *const pkt_data,
-                            owl_captured_request *request)
+                            owl_captured_request *const request)
 {
   // Current packet's ID:
   memcpy(&request->packet_id, pkt_data,
@@ -1327,8 +1327,8 @@ void extract_packet_numbers(const u_char *pkt_data,
  * Ideas of improvement:
  *   http://www.unixgarden.com/index.php/gnu-linux-magazine-hs/introduction-a-la-programmation-wifi-en-c-sous-netbsd#8-exemple-n°5-radiotap
  */
-bool extract_radiotap_ss(const u_char *pkt_data,
+bool extract_radiotap_ss(const u_char *const pkt_data,
-                         owl_captured_request *request)
+                         owl_captured_request *const request)
 {
   uint32_t rtap_presentflags ;
   uint_fast16_t rtap_position ;
@@ -1395,7 +1395,8 @@ bool extract_radiotap_ss(const u_char *pkt_data,
  * To advance to the next available position, you can also use the macro
  * SKIP_FIELD(), which is a simple wrapper around this function.
  */
-uint_fast16_t nat_align(uint_fast16_t offset, uint_fast8_t field_len)
+uint_fast16_t nat_align(const uint_fast16_t offset,
+                        const uint_fast8_t field_len)
 {
   uint_fast8_t alignment = offset % field_len ;
   if (alignment == 0)
@@ -1405,8 +1406,8 @@ uint_fast16_t nat_align(uint_fast16_t offset, uint_fast8_t field_len)
 
 
 
-void display_captured_request(owl_captured_request *request,
+void display_captured_request(const owl_captured_request *const request,
-                              const struct pcap_pkthdr *pkt_header)
+                              const struct pcap_pkthdr *const pkt_header)
 {
   owl_timestamp tmp_time ;
   char
@@ -1588,7 +1589,7 @@ void get_ip_addr(const char *const iface, char ip[INET_ADDRSTRLEN])
 /* *** Autocalibration functions *** */
 #ifdef OWLPS_LISTENER_USES_PTHREAD
 
-void* autocalibrate_hello(void *NULL_value)
+void* autocalibrate_hello(void *const NULL_value)
 {
   int send_sockfd ;
   struct sockaddr serv;
@@ -1620,7 +1621,7 @@ void* autocalibrate_hello(void *NULL_value)
 
 
 
-void* autocalibrate(void *NULL_value)
+void* autocalibrate(void *const NULL_value)
 {
   int nread ; // recvfrom return value
   int listen_sockfd ;
@@ -1703,7 +1704,7 @@ void send_autocalibration_request()
  * Returns the size of the packet.
  * In case of error, 0 is returned and *packet is not updated.
  */
-uint_fast16_t make_packet(uint8_t **packet)
+uint_fast16_t make_packet(uint8_t **const packet)
 {
   uint8_t *pkt ;
   uint_fast16_t size ; // Packet size
@@ -1773,7 +1774,7 @@ uint_fast16_t make_packet(uint8_t **packet)
 
 
 
-void sigint_handler(int num)
+void sigint_handler(const int num)
 {
   owl_sigint_handler(num) ;
   pcap_breakloop(capture_handler) ;
@@ -1781,7 +1782,7 @@ void sigint_handler(int num)
 
 
 
-void sigterm_handler(int num)
+void sigterm_handler(const int num)
 {
   owl_sigterm_handler(num) ;
   pcap_breakloop(capture_handler) ;

owlps-udp-to-http/owlps-udp-to-http.c

@@ -126,7 +126,7 @@ int main(int argc, char *argv[])
 }
 
 
-void parse_command_line(int argc, char **argv)
+void parse_command_line(const int argc, char *const *argv)
 {
   parse_options(argc, argv) ;
   check_configuration() ;
@@ -136,7 +136,7 @@ void parse_command_line(int argc, char **argv)
 }
 
 
-void parse_options(int argc, char **argv)
+void parse_options(const int argc, char *const *argv)
 {
   int opt ;
 
@@ -235,7 +235,7 @@ int receive_udp()
 /*
  * Adds a new owl_result to the results' list.
  */
-void store_result(owl_result *new_result)
+void store_result(owl_result *const new_result)
 {
   sem_wait(&lock_results) ;
 
@@ -350,7 +350,7 @@ int init_tcp_socket()
 /*
  * Waits for requests from HTTP clients.
  */
-void* tcp_server(void *NULL_value)
+void* tcp_server(void *const NULL_value)
 {
   int newsockfd ;
   ssize_t nbytes ; // recv/send return value
@@ -417,10 +417,11 @@ void* tcp_server(void *NULL_value)
 /*
  * Reads a message and search for a request in it.
  * Returns the identifier of a request if found, or 0 if not found.
+ * The text of the request is stored in 'client_request'.
  */
 int
 extract_request_from_message(char client_request[CLIENT_REQUEST_STRLEN],
-                             char *client_message)
+                             const char *const client_message)
 {
   char *token ;
 
@@ -453,7 +454,7 @@ extract_request_from_message(char client_request[CLIENT_REQUEST_STRLEN],
 /*
  * Prepare the answer string to send to the TCP client.
  */
-void prepare_answer(int request_id)
+void prepare_answer(const int request_id)
 {
   // Reset the answer's length:
   answer_strlen = ANSWER_HDR_STRLEN ;
@@ -577,7 +578,7 @@ void prepare_answer(int request_id)
  * greater than the current size, shrink it if the current size is
  * greater than the double of new_size.
  */
-void realloc_answer(size_t new_size)
+void realloc_answer(const size_t new_size)
 {
   if (new_size > answer_buflen)
     answer_buflen = new_size ;

owlps-udp-to-http/owlps-udp-to-http.h

@@ -55,20 +55,20 @@ typedef struct _results_list
 } results_list ;
 
 
-void parse_command_line(int argc, char **argv) ;
+void parse_command_line(const int argc, char *const *argv) ;
-void parse_options(int argc, char **argv) ;
+void parse_options(const int argc, char *const *argv) ;
 void check_configuration(void) ;
 void print_configuration(void) ;
 
 int receive_udp(void) ;
-void store_result(owl_result *result) ;
+void store_result(owl_result *const result) ;
 int init_tcp_socket(void) ;
-void* tcp_server(void *NULL_value) ;
+void* tcp_server(void *const NULL_value) ;
 int
 extract_request_from_message(char client_request[CLIENT_REQUEST_STRLEN],
-                             char *client_message) ;
+                             const char *const client_message) ;
-void prepare_answer(int request_id) ;
+void prepare_answer(const int request_id) ;
-void realloc_answer(size_t new_size) ;
+void realloc_answer(const size_t new_size) ;
 void free_results_list(void) ;
 
 void print_usage(void) ;