int main(int argc, char **argv)
{
char c;
char *flags=0;
optind = 0;
while ((c = getopt(argc, argv, "vi:x:Mp:")) !=EOF) {
switch (c) {
case 'i':
cfile = optarg;
insert = 1;
break;
case 'x':
extract = 1;
cfile = optarg;
break;
case 'M':
makemagic = 1;
break;
case 'v':
view = 1;
break;
case 'p':
setflags = 1;
flags = optarg;
break;
default: usage();
}
}
dexefile = argv[optind];
if (!dexefile) usage();
if ((insert || extract) && !cfile) usage();
if (insert) {
putconf();
if (setflags) changeflags(flags);
}
else if (view) viewconf();
else if (setflags) changeflags(flags);
else if (extract) getconf();
else usage();
return 0;
}
int main(int argc, char *argv[]) {
int opt;
int opt_list = 0;
char *conf_file = CONF_FILE;
// parse arguments
while ((opt = getopt(argc, argv, "c:l")) != -1) {
switch (opt) {
case 'c':
conf_file = optarg;
break;
case 'l':
opt_list = 1;
break;
}
}
if (optind >= argc) {
fprintf(stderr, "ERROR: no hostname given\n");
exit(1);
}
// open config file
char data[DATA_SIZE];
FILE *f = fopen(conf_file, "r");
if (f == NULL) {
fprintf(stderr, "ERROR: config file %s does not exist\n", conf_file);
exit(1);
}
// store default configuration
putconf("alias_last -last");
putconf("alias_text unavailable");
putconf("data_port 4411");
putconf("data_timeout 2");
putconf("relay_port 22");
// store config settings
while (fgets(data, DATA_SIZE, f) != NULL) {
if (strlen(data) == DATA_SIZE - 1) {
fprintf(stderr, "ERROR: config entry \"%s\" too long\n", data);
exit(1);
}
if (data[strlen(data) - 1] == '\n') data[strlen(data) - 1] = 0;
if (data[strlen(data) - 1] == '\r') data[strlen(data) - 1] = 0;
putconf(data);
}
fclose(f);
// check required config settings
for (int i = 0; i < sizeof(conf_req) / sizeof(char *); i++) {
char *tmp = getconf(conf_req[i]);
if (tmp == NULL) {
fprintf(stderr, "ERROR: config parameter %s is not defined\n",
conf_req[i]);
exit(1);
}
}
// copy argument
char arg[strlen(argv[optind]) + 1];
strcpy(arg, argv[optind]);
// chop off domain
char *alias_domain = getconf("alias_domain");
char *tmp = strstr(arg, alias_domain);
if (tmp == arg + strlen(arg) - strlen(alias_domain)) tmp[0] = 0;
// chop off last
int last = 0;
char *alias_last = getconf("alias_last");
tmp = strstr(arg, alias_last);
if (tmp == arg + strlen(arg) - strlen(alias_last)) {
tmp[0] = 0;
last = 1;
}
// find default hosts for given alias
char hosts_alias[strlen(arg) + 7];
sprintf(hosts_alias, "hosts_%s", arg);
char *defaults = getconf(hosts_alias);
if (defaults != NULL) {
// given host matches defined alias, so load balance
// construct balancing request
char sdata[DATA_SIZE];
snprintf(sdata, DATA_SIZE, "%s%s %d", arg,
last ? getconf("alias_last") : "", getuid());
// concatenate optional arguments to request
for (int i = optind + 1; i < argc; i++) {
if (strlen(argv[i]) + 2 > DATA_SIZE - strlen(sdata)) {
fprintf(stderr, "ERROR: excessive argument length\n");
exit(1);
}
strncat(sdata, argv[i], DATA_SIZE - strlen(sdata) - 2);
}
strcat(sdata, "\n");
// retrieve least loaded hosts from data server or time out
signal(SIGALRM, timeout);
char *host = strdup(getconf("data_host"));
for (host = strtok(host, " "); host; host = strtok(NULL, " ")) {
// resolve host name outside alarm to avoid reentrancy issues
struct addrinfo *ainfo = resolve(host);
alarm(igetconf("data_timeout"));
if (sigsetjmp(env, 1) != SIGALRM && !getdata(sdata, data, ainfo)) break;
// loop to try alternate data servers on failure
alarm(0);
}
alarm(0);
if (host == NULL) {
// copy default data on failed retrieval for strtok
strncpy(data, defaults, DATA_SIZE - 1);
data[DATA_SIZE - 1] = 0;
}
if (strspn(data, " ") == strlen(data)) {
// data is empty so no hosts available
fprintf(stderr, "ERROR: all hosts for alias %s are %s\n",
arg, getconf("alias_text"));
exit(1);
}
// count number of hosts in data
host = data;
long n = 1;
while ((host = strchr(host + 1, ' ')) != NULL) n++;
// pick random host from data
srand(time(NULL));
n = rand() % n;
for (host = strtok(data, " "); n-- > 0; host = strtok(NULL, " "));
if (opt_list) {
// print chosen host
printf("%s\n", host);
exit(0);
} else {
// connect to chosen host
execl(getconf("relay_path"), getconf("relay_path"), host,
getconf("relay_port"), NULL);
// does not return
}
}
// given host does not match alias, so pass through untouched
if (opt_list) {
// print given host
printf("%s\n", argv[optind]);
} else {
// connect to given host
execl(getconf("relay_path"), getconf("relay_path"), argv[optind],
getconf("relay_port"), NULL);
// does not return
}
}
