[lib-client] Use const arguments wherever possible

TODO

@@ -4,7 +4,7 @@
 - Use string for network exchanges?
 - Mark arguments as const in function headers if needed
    That is done in the owlps-positioning C++ code, but not constantly
-   in C modules.
+   in C modules. [Done in libowlps & libowlps-client.]
 - Allow to use hostnames instead of IP addresses.
 - Use struct ether_addr to store MAC addresses?
    We could use the struct ether_addr to store binary MAC addresses,

libowlps-client/libowlps-client.c

@@ -16,9 +16,10 @@
  * 'iface' if specified (if you want the interface to be selected,
  * automatically, this parameter should be NULL or an empty string).
  */
-int owlclient_create_trx_socket(char *dest_ip, uint_fast16_t dest_port,
+int owlclient_create_trx_socket(const char *const dest_ip,
-                                struct sockaddr_in *server,
+                                const uint_fast16_t dest_port,
-                                char *iface)
+                                struct sockaddr_in *const server,
+                                const char *const iface)
 {
   struct sockaddr_in client ;
 
@@ -41,7 +42,7 @@ int owlclient_create_trx_socket(char *dest_ip, uint_fast16_t dest_port,
 
 
 /* Selects 'iface' as sending interface for the socket 'sockfd'. */
-void owlclient_use_iface(int sockfd, char *iface)
+void owlclient_use_iface(const int sockfd, const char *const iface)
 {
   if (setsockopt(sockfd, SOL_SOCKET, SO_BINDTODEVICE, iface,
                  strlen(iface) + 1) == -1)
@@ -55,9 +56,12 @@ void owlclient_use_iface(int sockfd, char *iface)
 
 
 
-void owlclient_send_request(int sockfd, struct sockaddr_in *server,
+void owlclient_send_request(const int sockfd,
-                            void *packet, uint_fast16_t packet_size,
+                            const struct sockaddr_in *const server,
-                            uint_fast16_t nb_pkt, uint_fast32_t delay)
+                            const void *const packet,
+                            const uint_fast16_t packet_size,
+                            const uint_fast16_t nb_pkt,
+                            const uint_fast32_t delay)
 {
   uint_fast16_t i ;
 
@@ -82,8 +86,10 @@ void owlclient_send_request(int sockfd, struct sockaddr_in *server,
 
 
 
-void owlclient_send_packet(int sockfd, struct sockaddr_in *server,
+void owlclient_send_packet(const int sockfd,
-                           void *packet, uint_fast16_t packet_size)
+                           const struct sockaddr_in *const server,
+                           const void *const packet,
+                           const uint_fast16_t packet_size)
 {
   ssize_t nsent = sendto(sockfd, packet, packet_size, 0,
                          (struct sockaddr *) server,

libowlps-client/owlps-client.h

@@ -14,15 +14,21 @@
 
 
 /* Function headers */
-int owlclient_create_trx_socket(char *dest_ip, uint_fast16_t dest_port,
+int owlclient_create_trx_socket(const char *const dest_ip,
-                                struct sockaddr_in *server,
+                                const uint_fast16_t dest_port,
-                                char *iface) ;
+                                struct sockaddr_in *const server,
-void owlclient_use_iface(int sockfd, char *iface) ;
+                                const char *const iface) ;
-void owlclient_send_request(int sockfd, struct sockaddr_in *server,
+void owlclient_use_iface(const int sockfd, const char *const iface) ;
-                            void *packet, uint_fast16_t packet_size,
+void owlclient_send_request(const int sockfd,
-                            uint_fast16_t nb_pkt, uint_fast32_t delay) ;
+                            const struct sockaddr_in *const server,
-void owlclient_send_packet(int sockfd, struct sockaddr_in *server,
+                            const void *const packet,
-                           void *packet, uint_fast16_t packet_size) ;
+                            const uint_fast16_t packet_size,
+                            const uint_fast16_t nb_pkt,
+                            const uint_fast32_t delay) ;
+void owlclient_send_packet(const int sockfd,
+                           const struct sockaddr_in *const server,
+                           const void *const packet,
+                           const uint_fast16_t packet_size) ;
 
 
 #endif // _LIBOWLPS_CLIENT_