Added -b option to specify bind address, using getaddrinfo() for address and port + getnameinfo() for logging name and port used.

This commit is contained in:
Michael Jumper 2011-12-10 23:17:25 -08:00
parent ac43e37399
commit 3e06b326d9

View File

@ -43,6 +43,7 @@
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <errno.h>
@ -177,7 +178,10 @@ int main(int argc, char* argv[]) {
/* Server */
int socket_fd;
struct sockaddr_in server_addr;
struct addrinfo* addresses;
struct addrinfo* current_address;
char bound_address[1024];
char bound_port[64];
int opt_on = 1;
/* Client */
@ -186,37 +190,45 @@ int main(int argc, char* argv[]) {
int connected_socket_fd;
/* Arguments */
int listen_port = 4822; /* Default port */
char* listen_address = NULL; /* Default address of INADDR_ANY */
char* listen_port = "4822"; /* Default port */
char* pidfile = NULL;
int opt;
char* pidfile = NULL;
/* General */
int retval;
/* Daemon Process */
pid_t daemon_pid;
/* Parse arguments */
while ((opt = getopt(argc, argv, "l:p:")) != -1) {
while ((opt = getopt(argc, argv, "l:b:p:")) != -1) {
if (opt == 'l') {
listen_port = atoi(optarg);
if (listen_port <= 0) {
fprintf(stderr, "Invalid port: %s\n", optarg);
exit(EXIT_FAILURE);
}
listen_port = strdup(optarg);
}
else if (opt == 'b') {
listen_address = strdup(optarg);
}
else if (opt == 'p') {
pidfile = strdup(optarg);
}
else {
fprintf(stderr, "USAGE: %s [-l LISTENPORT] [-p PIDFILE]\n", argv[0]);
fprintf(stderr, "USAGE: %s"
" [-l LISTENPORT]"
" [-b LISTENADDRESS]"
" [-p PIDFILE]\n", argv[0]);
exit(EXIT_FAILURE);
}
}
/* Get binding address */
memset(&server_addr, 0, sizeof(server_addr)); /* Zero struct */
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = INADDR_ANY;
server_addr.sin_port = htons(listen_port);
/* Get addresses for binding */
if ((retval = getaddrinfo(listen_address, listen_port, NULL, &addresses))) {
fprintf(stderr, "Error parsing given address or port: %s\n",
gai_strerror(retval));
exit(EXIT_FAILURE);
}
/* Get socket */
socket_fd = socket(AF_INET, SOCK_STREAM, 0);
@ -225,16 +237,38 @@ int main(int argc, char* argv[]) {
exit(EXIT_FAILURE);
}
/* Allow socket reuse */
if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, (void*) &opt_on, sizeof(opt_on))) {
fprintf(stderr, "Warning: Unable to set socket options for reuse: %s\n", strerror(errno));
}
/* Bind socket to address */
if (bind(socket_fd, (struct sockaddr*) &server_addr,
sizeof(server_addr)) < 0) {
fprintf(stderr, "Error binding socket: %s\n", strerror(errno));
/* Attempt binding of each address until success */
current_address = addresses;
while (current_address != NULL) {
/* Attempt to bind socket to address */
if (bind(socket_fd,
current_address->ai_addr,
current_address->ai_addrlen) == 0) {
/* Done if successful bind */
break;
}
/* Otherwise log error */
else
fprintf(stderr, "Error binding socket: %s\n", strerror(errno));
current_address = current_address->ai_next;
}
/* If unable to bind to anything, fail */
if (current_address == NULL) {
fprintf(stderr, "Unable to bind socket to any addresses.\n");
exit(EXIT_FAILURE);
}
}
/* Fork into background */
daemon_pid = fork();
@ -271,9 +305,6 @@ int main(int argc, char* argv[]) {
/* Open log */
openlog(NULL, LOG_PID, LOG_DAEMON);
/* Otherwise, this is the daemon */
syslog(LOG_INFO, "Listening on port %i", listen_port);
/* Ignore SIGPIPE */
if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) {
syslog(LOG_ERR, "Could not set handler for SIGPIPE to ignore. SIGPIPE may cause termination of the daemon.");
@ -284,6 +315,19 @@ int main(int argc, char* argv[]) {
syslog(LOG_ERR, "Could not set handler for SIGCHLD to ignore. Child processes may pile up in the process table.");
}
/* Log address and port */
if (getnameinfo(current_address->ai_addr, current_address->ai_addrlen,
bound_address, sizeof(bound_address),
bound_port, sizeof(bound_port),
0))
syslog(LOG_WARNING, "Could not resolve name of listening host.");
else
syslog(LOG_INFO,
"Listening on host %s, port %s", bound_address, bound_port);
/* Free addresses */
freeaddrinfo(addresses);
/* Daemon loop */
for (;;) {