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/**
* (C) 2007-20 - ntop.org and contributors
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not see see <http://www.gnu.org/licenses/>
*
*/
/* Supernode for n2n-2.x */
#include "n2n.h"
#include "header_encryption.h"
static n2n_sn_t sss_node;
/** Load the list of allowed communities. Existing/previous ones will be removed
*
*/
static int load_allowed_sn_community(n2n_sn_t *sss, char *path) {
char buffer[4096], *line;
FILE *fd = fopen(path, "r");
struct sn_community *s, *tmp;
uint32_t num_communities = 0;
if(fd == NULL) {
traceEvent(TRACE_WARNING, "File %s not found", path);
return -1;
}
HASH_ITER(hh, sss->communities, s, tmp) {
HASH_DEL(sss->communities, s);
if (NULL != s->header_encryption_ctx)
free (s->header_encryption_ctx);
free(s);
}
while((line = fgets(buffer, sizeof(buffer), fd)) != NULL) {
int len = strlen(line);
if((len < 2) || line[0] == '#')
continue;
len--;
while(len > 0) {
if((line[len] == '\n') || (line[len] == '\r')) {
line[len] = '\0';
len--;
} else
break;
}
s = (struct sn_community*)calloc(1,sizeof(struct sn_community));
if(s != NULL) {
strncpy((char*)s->community, line, N2N_COMMUNITY_SIZE-1);
s->community[N2N_COMMUNITY_SIZE-1] = '\0';
/* we do not know if header encryption is used in this community,
* first packet will show. just in case, setup the key. */
s->header_encryption = HEADER_ENCRYPTION_UNKNOWN;
packet_header_setup_key (s->community, &(s->header_encryption_ctx), &(s->header_iv_ctx));
HASH_ADD_STR(sss->communities, community, s);
num_communities++;
traceEvent(TRACE_INFO, "Added allowed community '%s' [total: %u]",
(char*)s->community, num_communities);
}
}
fclose(fd);
traceEvent(TRACE_NORMAL, "Loaded %u communities from %s",
num_communities, path);
/* No new communities will be allowed */
sss->lock_communities = 1;
return(0);
}
/* *************************************************** */
/** Help message to print if the command line arguments are not valid. */
static void help() {
print_n2n_version();
printf("supernode <config file> (see supernode.conf)\n"
"or\n"
);
printf("supernode ");
printf("-l <local port> ");
printf("-c <path> ");
#if defined(N2N_HAVE_DAEMON)
printf("[-f] ");
#endif
#ifndef WIN32
printf("[-u <uid> -g <gid>] ");
#endif /* ifndef WIN32 */
printf("[-t <mgmt port>] ");
printf("[-v] ");
printf("\n\n");
printf("-l <port>\tSet UDP main listen port to <port>\n");
printf("-c <path>\tFile containing the allowed communities.\n");
#if defined(N2N_HAVE_DAEMON)
printf("-f \tRun in foreground.\n");
#endif /* #if defined(N2N_HAVE_DAEMON) */
#ifndef WIN32
printf("-u <UID>\tUser ID (numeric) to use when privileges are dropped.\n");
printf("-g <GID>\tGroup ID (numeric) to use when privileges are dropped.\n");
#endif /* ifndef WIN32 */
printf("-t <port>\tManagement UDP Port (for multiple supernodes on a machine).\n");
printf("-v \tIncrease verbosity. Can be used multiple times.\n");
printf("-h \tThis help message.\n");
printf("\n");
exit(1);
}
/* *************************************************** */
static int setOption(int optkey, char *_optarg, n2n_sn_t *sss) {
//traceEvent(TRACE_NORMAL, "Option %c = %s", optkey, _optarg ? _optarg : "");
switch(optkey) {
case 'l': /* local-port */
sss->lport = atoi(_optarg);
break;
case 't': /* mgmt-port */
sss->mport = atoi(_optarg);
break;
#ifndef WIN32
case 'u': /* unprivileged uid */
sss->userid = atoi(_optarg);
break;
case 'g': /* unprivileged uid */
sss->groupid = atoi(_optarg);
break;
#endif
case 'c': /* community file */
load_allowed_sn_community(sss, _optarg);
break;
case 'f': /* foreground */
sss->daemon = 0;
break;
case 'h': /* help */
help();
break;
case 'v': /* verbose */
setTraceLevel(getTraceLevel() + 1);
break;
default:
traceEvent(TRACE_WARNING, "Unknown option -%c: Ignored.", (char)optkey);
return(-1);
}
return(0);
}
/* *********************************************** */
static const struct option long_options[] = {
{ "communities", required_argument, NULL, 'c' },
{ "foreground", no_argument, NULL, 'f' },
{ "local-port", required_argument, NULL, 'l' },
{ "mgmt-port", required_argument, NULL, 't' },
{ "help" , no_argument, NULL, 'h' },
{ "verbose", no_argument, NULL, 'v' },
{ NULL, 0, NULL, 0 }
};
/* *************************************************** */
/* read command line options */
static int loadFromCLI(int argc, char * const argv[], n2n_sn_t *sss) {
u_char c;
while((c = getopt_long(argc, argv, "fl:u:g:t:c:vh",
long_options, NULL)) != '?') {
if(c == 255) break;
setOption(c, optarg, sss);
}
return 0;
}
/* *************************************************** */
static char *trim(char *s) {
char *end;
while(isspace(s[0]) || (s[0] == '"') || (s[0] == '\''))
s++;
if(s[0] == 0) return s;
end = &s[strlen(s) - 1];
while(end > s
&& (isspace(end[0])|| (end[0] == '"') || (end[0] == '\'')))
end--;
end[1] = 0;
return s;
}
/* *************************************************** */
/* parse the configuration file */
static int loadFromFile(const char *path, n2n_sn_t *sss) {
char buffer[4096], *line, *key, *value;
u_int line_len, opt_name_len;
FILE *fd;
const struct option *opt;
fd = fopen(path, "r");
if(fd == NULL) {
traceEvent(TRACE_WARNING, "Config file %s not found", path);
return -1;
}
while((line = fgets(buffer, sizeof(buffer), fd)) != NULL) {
line = trim(line);
value = NULL;
if((line_len = strlen(line)) < 2 || line[0] == '#')
continue;
if(!strncmp(line, "--", 2)) { /* long opt */
key = &line[2], line_len -= 2;
opt = long_options;
while(opt->name != NULL) {
opt_name_len = strlen(opt->name);
if(!strncmp(key, opt->name, opt_name_len)
&& (line_len <= opt_name_len
|| key[opt_name_len] == '\0'
|| key[opt_name_len] == ' '
|| key[opt_name_len] == '=')) {
if(line_len > opt_name_len) key[opt_name_len] = '\0';
if(line_len > opt_name_len + 1) value = trim(&key[opt_name_len + 1]);
// traceEvent(TRACE_NORMAL, "long key: %s value: %s", key, value);
setOption(opt->val, value, sss);
break;
}
opt++;
}
} else if(line[0] == '-') { /* short opt */
key = &line[1], line_len--;
if(line_len > 1) key[1] = '\0';
if(line_len > 2) value = trim(&key[2]);
// traceEvent(TRACE_NORMAL, "key: %c value: %s", key[0], value);
setOption(key[0], value, sss);
} else {
traceEvent(TRACE_WARNING, "Skipping unrecognized line: %s", line);
continue;
}
}
fclose(fd);
return 0;
}
/* *************************************************** */
#ifdef __linux__
static void dump_registrations(int signo) {
struct sn_community *comm, *ctmp;
struct peer_info *list, *tmp;
char buf[32];
time_t now = time(NULL);
u_int num = 0;
traceEvent(TRACE_NORMAL, "====================================");
HASH_ITER(hh, sss_node.communities, comm, ctmp) {
traceEvent(TRACE_NORMAL, "Dumping community: %s", comm->community);
HASH_ITER(hh, comm->edges, list, tmp) {
if(list->sock.family == AF_INET)
traceEvent(TRACE_NORMAL, "[id: %u][MAC: %s][edge: %u.%u.%u.%u:%u][last seen: %u sec ago]",
++num, macaddr_str(buf, list->mac_addr),
list->sock.addr.v4[0], list->sock.addr.v4[1], list->sock.addr.v4[2], list->sock.addr.v4[3],
list->sock.port,
now-list->last_seen);
else
traceEvent(TRACE_NORMAL, "[id: %u][MAC: %s][edge: IPv6:%u][last seen: %u sec ago]",
++num, macaddr_str(buf, list->mac_addr), list->sock.port,
now-list->last_seen);
}
}
traceEvent(TRACE_NORMAL, "====================================");
}
#endif
/* *************************************************** */
static int keep_running;
#if defined(__linux__) || defined(WIN32)
#ifdef WIN32
BOOL WINAPI term_handler(DWORD sig)
#else
static void term_handler(int sig)
#endif
{
static int called = 0;
if(called) {
traceEvent(TRACE_NORMAL, "Ok I am leaving now");
_exit(0);
} else {
traceEvent(TRACE_NORMAL, "Shutting down...");
called = 1;
}
keep_running = 0;
#ifdef WIN32
return(TRUE);
#endif
}
#endif /* defined(__linux__) || defined(WIN32) */
/* *************************************************** */
/** Main program entry point from kernel. */
int main(int argc, char * const argv[]) {
int rc;
#ifndef WIN32
struct passwd *pw = NULL;
#endif
sn_init(&sss_node);
if((argc >= 2) && (argv[1][0] != '-')) {
rc = loadFromFile(argv[1], &sss_node);
if(argc > 2)
rc = loadFromCLI(argc, argv, &sss_node);
} else if(argc > 1)
rc = loadFromCLI(argc, argv, &sss_node);
else
#ifdef WIN32
/* Load from current directory */
rc = loadFromFile("supernode.conf", &sss_node);
#else
rc = -1;
#endif
if(rc < 0)
help();
#if defined(N2N_HAVE_DAEMON)
if(sss_node.daemon) {
setUseSyslog(1); /* traceEvent output now goes to syslog. */
if(-1 == daemon(0, 0)) {
traceEvent(TRACE_ERROR, "Failed to become daemon.");
exit(-5);
}
}
#endif /* #if defined(N2N_HAVE_DAEMON) */
traceEvent(TRACE_DEBUG, "traceLevel is %d", getTraceLevel());
sss_node.sock = open_socket(sss_node.lport, 1 /*bind ANY*/);
if(-1 == sss_node.sock) {
traceEvent(TRACE_ERROR, "Failed to open main socket. %s", strerror(errno));
exit(-2);
} else {
traceEvent(TRACE_NORMAL, "supernode is listening on UDP %u (main)", sss_node.lport);
}
sss_node.mgmt_sock = open_socket(sss_node.mport, 0 /* bind LOOPBACK */);
if(-1 == sss_node.mgmt_sock) {
traceEvent(TRACE_ERROR, "Failed to open management socket. %s", strerror(errno));
exit(-2);
} else
traceEvent(TRACE_NORMAL, "supernode is listening on UDP %u (management)", sss_node.mport);
#ifndef WIN32
if (((pw = getpwnam ("n2n")) != NULL) || ((pw = getpwnam ("nobody")) != NULL)) {
sss_node.userid = sss_node.userid == 0 ? pw->pw_uid : 0;
sss_node.groupid = sss_node.groupid == 0 ? pw->pw_gid : 0;
}
if((sss_node.userid != 0) || (sss_node.groupid != 0)) {
traceEvent(TRACE_NORMAL, "Dropping privileges to uid=%d, gid=%d",
(signed int)sss_node.userid, (signed int)sss_node.groupid);
/* Finished with the need for root privileges. Drop to unprivileged user. */
if((setgid(sss_node.groupid) != 0)
|| (setuid(sss_node.userid) != 0)) {
traceEvent(TRACE_ERROR, "Unable to drop privileges [%u/%s]", errno, strerror(errno));
exit(1);
}
}
if((getuid() == 0) || (getgid() == 0))
traceEvent(TRACE_WARNING, "Running as root is discouraged, check out the -u/-g options");
#endif
traceEvent(TRACE_NORMAL, "supernode started");
#ifdef __linux__
signal(SIGTERM, term_handler);
signal(SIGINT, term_handler);
signal(SIGHUP, dump_registrations);
#endif
#ifdef WIN32
SetConsoleCtrlHandler(term_handler, TRUE);
#endif
keep_running = 1;
return run_sn_loop(&sss_node, &keep_running);
}