first-free-port : meilleure gestion des erreurs

This commit is contained in:
Hippolyte Chauvin 2023-12-04 23:07:42 +01:00
parent c16666a3f9
commit 519f9d415f

View file

@ -3,6 +3,7 @@
#include <fcntl.h>
#include <sysexits.h>
#include <string.h>
#include <errno.h>
#define MIN_TCP_PORT 1
#define TCP_TABLE "/proc/net/tcp"
@ -12,6 +13,13 @@
#define LISTENING_HEX "0A"
#define PORTS_BLOCKS_TO_ALLOW 4
/**
* Print a nice error message
*/
static void print_error(char *name, const char *message) {
fprintf(stderr, "%s: %s\n", name, message);
}
/**
* Get all the listening TCP ports
*/
@ -81,20 +89,25 @@ int main(int argc, char *argv[]) {
}
if (!is_valid_tcp_port(current_port)) {
fprintf(stderr, "%s: provide a valid TCP port number as first argument.\n", argv[0]);
print_error(argv[0], "provide a valid TCP port number as first argument.");
return EX_USAGE;
}
// Open TCP table
FILE *tcp_table_fptr = fopen(TCP_TABLE, "r");
if (tcp_table_fptr == NULL) {
fprintf(stderr, "%s: error opening the TCP table.\n", argv[0]);
return EX_OSFILE;
print_error(argv[0], "error opening the TCP table.");
return errno;
}
unsigned short *listening_ports = malloc(PORTS_BLOCKS_TO_ALLOW * sizeof(unsigned short));
listening_ports = get_listening_ports(listening_ports, tcp_table_fptr);
if (fclose(tcp_table_fptr) != 0) {
print_error(argv[0], "can't close the TCP table.");
return errno;
}
// Check if the current port is available, add
while (!is_port_available(current_port, listening_ports)) {
current_port++;
@ -106,7 +119,7 @@ int main(int argc, char *argv[]) {
printf("%d\n", current_port);
return EXIT_SUCCESS;
} else {
fprintf(stderr, "%s: no more ports available; how did you fuck up that bad ???\n", argv[0]);
print_error(argv[0], "no more ports available; how did you fuck up that bad ???");
return EX_TEMPFAIL;
}
}