/[LeafOK_CVS]/lbbs/src/net_server.c
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Revision 1.58 - (hide annotations)
Sat Jun 7 11:28:29 2025 UTC (9 months, 1 week ago) by sysadm
Branch: MAIN
Changes since 1.57: +3 -3 lines
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1 sysadm 1.1 /***************************************************************************
2 sysadm 1.13 net_server.c - description
3     -------------------
4 sysadm 1.18 Copyright : (C) 2004-2025 by Leaflet
5     Email : leaflet@leafok.com
6 sysadm 1.1 ***************************************************************************/
7    
8     /***************************************************************************
9     * *
10     * This program is free software; you can redistribute it and/or modify *
11     * it under the terms of the GNU General Public License as published by *
12 sysadm 1.18 * the Free Software Foundation; either version 3 of the License, or *
13 sysadm 1.1 * (at your option) any later version. *
14     * *
15     ***************************************************************************/
16    
17 sysadm 1.19 #define _XOPEN_SOURCE 500
18     #define _POSIX_C_SOURCE 200809L
19     #define _GNU_SOURCE
20    
21 sysadm 1.14 #include "net_server.h"
22 sysadm 1.1 #include "common.h"
23 sysadm 1.55 #include "bbs_main.h"
24     #include "bbs.h"
25 sysadm 1.14 #include "log.h"
26 sysadm 1.7 #include "io.h"
27 sysadm 1.44 #include "init.h"
28 sysadm 1.19 #include "menu.h"
29 sysadm 1.55 #include "database.h"
30     #include "login.h"
31 sysadm 1.35 #include "file_loader.h"
32 sysadm 1.42 #include "section_list_loader.h"
33 sysadm 1.20 #include <errno.h>
34     #include <fcntl.h>
35     #include <string.h>
36 sysadm 1.19 #include <signal.h>
37 sysadm 1.20 #include <stdlib.h>
38 sysadm 1.19 #include <unistd.h>
39     #include <sys/syscall.h>
40 sysadm 1.7 #include <sys/socket.h>
41 sysadm 1.19 #include <sys/wait.h>
42 sysadm 1.25 #include <sys/epoll.h>
43 sysadm 1.9 #include <arpa/inet.h>
44 sysadm 1.47 #include <netinet/in.h>
45 sysadm 1.31 #include <systemd/sd-daemon.h>
46 sysadm 1.55 #include <libssh/libssh.h>
47     #include <libssh/server.h>
48     #include <libssh/callbacks.h>
49 sysadm 1.3
50 sysadm 1.44 struct process_sockaddr_t
51     {
52     pid_t pid;
53     in_addr_t s_addr;
54     };
55     typedef struct process_sockaddr_t PROCESS_SOCKADDR;
56    
57 sysadm 1.48 static PROCESS_SOCKADDR process_sockaddr_pool[MAX_CLIENT_LIMIT];
58 sysadm 1.44
59 sysadm 1.58 #define SSH_AUTH_MAX_DURATION (60 * 1000) // milliseconds
60 sysadm 1.55
61     struct ssl_server_cb_data_t
62     {
63     int tries;
64     int error;
65     };
66    
67     static int auth_password(ssh_session session, const char *user,
68     const char *password, void *userdata)
69     {
70     struct ssl_server_cb_data_t *p_data = userdata;
71     int ret;
72    
73     if (strcmp(user, "guest") == 0)
74     {
75 sysadm 1.57 ret = load_guest_info();
76 sysadm 1.55 }
77     else
78     {
79 sysadm 1.57 ret = check_user(user, password);
80 sysadm 1.55 }
81    
82     if (ret == 0)
83     {
84     return SSH_AUTH_SUCCESS;
85     }
86    
87     if ((++(p_data->tries)) >= BBS_login_retry_times)
88     {
89     p_data->error = 1;
90     }
91    
92     return SSH_AUTH_DENIED;
93     }
94    
95     static int pty_request(ssh_session session, ssh_channel channel, const char *term,
96     int x, int y, int px, int py, void *userdata)
97     {
98     return 0;
99     }
100    
101     static int shell_request(ssh_session session, ssh_channel channel, void *userdata)
102     {
103     return 0;
104     }
105    
106     static struct ssh_channel_callbacks_struct channel_cb = {
107     .channel_pty_request_function = pty_request,
108     .channel_shell_request_function = shell_request};
109    
110     static ssh_channel new_session_channel(ssh_session session, void *userdata)
111     {
112     if (SSH_channel != NULL)
113     {
114     return NULL;
115     }
116    
117     SSH_channel = ssh_channel_new(session);
118     ssh_callbacks_init(&channel_cb);
119     ssh_set_channel_callbacks(SSH_channel, &channel_cb);
120    
121     return SSH_channel;
122     }
123    
124 sysadm 1.56 static int fork_server(void)
125 sysadm 1.55 {
126     ssh_event event;
127     int pid;
128     int i;
129     int ret;
130    
131     struct ssl_server_cb_data_t cb_data = {
132     .tries = 0,
133     .error = 0,
134     };
135    
136     struct ssh_server_callbacks_struct cb = {
137     .userdata = &cb_data,
138     .auth_password_function = auth_password,
139     .channel_open_request_session_function = new_session_channel,
140     };
141    
142     pid = fork();
143    
144     if (pid > 0) // Parent process
145     {
146     SYS_child_process_count++;
147     log_common("Child process (%d) start\n", pid);
148     return pid;
149     }
150     else if (pid < 0) // Error
151     {
152     log_error("fork() error (%d)\n", errno);
153     return -1;
154     }
155    
156     // Child process
157    
158     if (close(socket_server[0]) == -1 || close(socket_server[1]) == -1)
159     {
160     log_error("Close server socket failed\n");
161     }
162    
163     SSH_session = ssh_new();
164    
165     if (SSH_v2)
166     {
167     if (ssh_bind_accept_fd(sshbind, SSH_session, socket_client) != SSH_OK)
168     {
169     log_error("ssh_bind_accept_fd() error: %s\n", ssh_get_error(SSH_session));
170     goto cleanup;
171     }
172    
173     ssh_bind_free(sshbind);
174    
175     ssh_callbacks_init(&cb);
176     ssh_set_server_callbacks(SSH_session, &cb);
177    
178     if (ssh_handle_key_exchange(SSH_session))
179     {
180     log_error("ssh_handle_key_exchange() error: %s\n", ssh_get_error(SSH_session));
181     goto cleanup;
182     }
183     ssh_set_auth_methods(SSH_session, SSH_AUTH_METHOD_PASSWORD);
184    
185     event = ssh_event_new();
186     ssh_event_add_session(event, SSH_session);
187    
188 sysadm 1.58 for (i = 0; i < SSH_AUTH_MAX_DURATION && !SYS_server_exit && !cb_data.error && SSH_channel == NULL; i += 100)
189 sysadm 1.55 {
190 sysadm 1.58 ret = ssh_event_dopoll(event, 100); // 0.1 second
191 sysadm 1.55 if (ret == SSH_ERROR)
192     {
193     log_error("ssh_event_dopoll() error: %s\n", ssh_get_error(SSH_session));
194     goto cleanup;
195     }
196     }
197    
198     if (cb_data.error)
199     {
200     log_error("SSH auth error, tried %d times\n", cb_data.tries);
201     goto cleanup;
202     }
203     }
204    
205     // Redirect Input
206     close(STDIN_FILENO);
207     if (dup2(socket_client, STDIN_FILENO) == -1)
208     {
209     log_error("Redirect stdin to client socket failed\n");
210     goto cleanup;
211     }
212    
213     // Redirect Output
214     close(STDOUT_FILENO);
215     if (dup2(socket_client, STDOUT_FILENO) == -1)
216     {
217     log_error("Redirect stdout to client socket failed\n");
218     goto cleanup;
219     }
220    
221     SYS_child_process_count = 0;
222    
223     bbs_main();
224    
225     cleanup:
226     // Child process exit
227     SYS_server_exit = 1;
228    
229     if (SSH_v2)
230     {
231     ssh_channel_free(SSH_channel);
232     ssh_disconnect(SSH_session);
233     }
234     else if (close(socket_client) == -1)
235     {
236     log_error("Close client socket failed\n");
237     }
238    
239     ssh_free(SSH_session);
240     ssh_finalize();
241    
242     // Close Input and Output for client
243     close(STDIN_FILENO);
244     close(STDOUT_FILENO);
245    
246     log_common("Process exit normally\n");
247     log_end();
248    
249     _exit(0);
250    
251     return 0;
252     }
253    
254 sysadm 1.52 int net_server(const char *hostaddr, in_port_t port[])
255 sysadm 1.1 {
256 sysadm 1.52 unsigned int addrlen;
257 sysadm 1.19 int ret;
258 sysadm 1.52 int flags[2];
259 sysadm 1.13 struct sockaddr_in sin;
260 sysadm 1.25 struct epoll_event ev, events[MAX_EVENTS];
261     int nfds, epollfd;
262 sysadm 1.19 siginfo_t siginfo;
263 sysadm 1.31 int sd_notify_stopping = 0;
264 sysadm 1.34 MENU_SET *p_bbs_menu_new;
265 sysadm 1.44 int i, j;
266     pid_t pid;
267 sysadm 1.51 int ssh_log_level = SSH_LOG_NOLOG;
268 sysadm 1.10
269 sysadm 1.51 ssh_init();
270    
271     sshbind = ssh_bind_new();
272    
273     if (ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_BINDADDR, hostaddr) < 0 ||
274     ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_BINDPORT, &port) < 0 ||
275     ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_HOSTKEY, SSH_HOST_KEYFILE) < 0 ||
276     ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_LOG_VERBOSITY, &ssh_log_level) < 0)
277     {
278     log_error("Error setting SSH bind options: %s\n", ssh_get_error(sshbind));
279     ssh_bind_free(sshbind);
280     return -1;
281     }
282 sysadm 1.10
283 sysadm 1.52 epollfd = epoll_create1(0);
284     if (epollfd < 0)
285 sysadm 1.13 {
286 sysadm 1.52 log_error("epoll_create1() error (%d)\n", errno);
287 sysadm 1.27 return -1;
288 sysadm 1.13 }
289 sysadm 1.10
290 sysadm 1.52 // Server socket
291     for (i = 0; i < 2; i++)
292 sysadm 1.23 {
293 sysadm 1.52 socket_server[i] = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
294 sysadm 1.23
295 sysadm 1.52 if (socket_server[i] < 0)
296     {
297     log_error("Create socket_server error (%d)\n", errno);
298     return -1;
299     }
300 sysadm 1.10
301 sysadm 1.52 sin.sin_family = AF_INET;
302     sin.sin_addr.s_addr = (hostaddr[0] != '\0' ? inet_addr(hostaddr) : INADDR_ANY);
303     sin.sin_port = htons(port[i]);
304    
305     // Reuse address and port
306     flags[i] = 1;
307     if (setsockopt(socket_server[i], SOL_SOCKET, SO_REUSEADDR, &flags[i], sizeof(flags[i])) < 0)
308     {
309     log_error("setsockopt SO_REUSEADDR error (%d)\n", errno);
310     }
311     if (setsockopt(socket_server[i], SOL_SOCKET, SO_REUSEPORT, &flags[i], sizeof(flags[i])) < 0)
312     {
313     log_error("setsockopt SO_REUSEPORT error (%d)\n", errno);
314     }
315 sysadm 1.1
316 sysadm 1.52 if (bind(socket_server[i], (struct sockaddr *)&sin, sizeof(sin)) < 0)
317     {
318     log_error("Bind address %s:%u error (%d)\n",
319     inet_ntoa(sin.sin_addr), ntohs(sin.sin_port), errno);
320     return -1;
321     }
322 sysadm 1.16
323 sysadm 1.52 if (listen(socket_server[i], 10) < 0)
324     {
325     log_error("Telnet socket listen error (%d)\n", errno);
326     return -1;
327     }
328 sysadm 1.13
329 sysadm 1.52 log_common("Listening at %s:%u\n", inet_ntoa(sin.sin_addr), ntohs(sin.sin_port));
330 sysadm 1.25
331 sysadm 1.52 ev.events = EPOLLIN;
332     ev.data.fd = socket_server[i];
333     if (epoll_ctl(epollfd, EPOLL_CTL_ADD, socket_server[i], &ev) == -1)
334 sysadm 1.30 {
335 sysadm 1.52 log_error("epoll_ctl(socket_server[%d]) error (%d)\n", i, errno);
336     if (close(epollfd) < 0)
337     {
338     log_error("close(epoll) error (%d)\n");
339     }
340     return -1;
341 sysadm 1.30 }
342 sysadm 1.52
343     flags[i] = fcntl(socket_server[i], F_GETFL, 0);
344     fcntl(socket_server[i], F_SETFL, flags[i] | O_NONBLOCK);
345 sysadm 1.25 }
346    
347 sysadm 1.31 // Startup complete
348     sd_notifyf(0, "READY=1\n"
349 sysadm 1.52 "STATUS=Listening at %s:%d (Telnet) and %s:%d (SSH2)\n"
350 sysadm 1.31 "MAINPID=%d",
351 sysadm 1.52 hostaddr, port[0], hostaddr, port[1], getpid());
352 sysadm 1.31
353 sysadm 1.19 while (!SYS_server_exit || SYS_child_process_count > 0)
354 sysadm 1.13 {
355 sysadm 1.31 if (SYS_server_exit && !sd_notify_stopping)
356     {
357     sd_notify(0, "STOPPING=1");
358     sd_notify_stopping = 1;
359     }
360 sysadm 1.37
361 sysadm 1.22 while ((SYS_child_exit || SYS_server_exit) && SYS_child_process_count > 0)
362 sysadm 1.19 {
363 sysadm 1.30 SYS_child_exit = 0;
364    
365 sysadm 1.19 siginfo.si_pid = 0;
366     ret = waitid(P_ALL, 0, &siginfo, WEXITED | WNOHANG);
367     if (ret == 0 && siginfo.si_pid > 0)
368     {
369 sysadm 1.30 SYS_child_exit = 1; // Retry waitid
370    
371 sysadm 1.19 SYS_child_process_count--;
372 sysadm 1.49 log_common("Child process (%d) exited\n", siginfo.si_pid);
373 sysadm 1.44
374 sysadm 1.45 if (siginfo.si_pid != section_list_loader_pid)
375 sysadm 1.44 {
376 sysadm 1.45 i = 0;
377     for (; i < BBS_max_client; i++)
378 sysadm 1.44 {
379 sysadm 1.45 if (process_sockaddr_pool[i].pid == siginfo.si_pid)
380     {
381     process_sockaddr_pool[i].pid = 0;
382     break;
383     }
384     }
385     if (i >= BBS_max_client)
386     {
387     log_error("Child process (%d) not found in process sockaddr pool\n", siginfo.si_pid);
388 sysadm 1.44 }
389     }
390 sysadm 1.19 }
391     else if (ret == 0)
392     {
393     break;
394     }
395     else if (ret < 0)
396     {
397     log_error("Error in waitid: %d\n", errno);
398     break;
399     }
400     }
401    
402 sysadm 1.22 if (SYS_server_exit && !SYS_child_exit && SYS_child_process_count > 0)
403 sysadm 1.21 {
404 sysadm 1.49 log_common("Notify %d child process to exit\n", SYS_child_process_count);
405 sysadm 1.21 if (kill(0, SIGTERM) < 0)
406     {
407     log_error("Send SIGTERM signal failed (%d)\n", errno);
408     }
409 sysadm 1.31
410     sd_notifyf(0, "STATUS=Waiting for %d child process to exit", SYS_child_process_count);
411 sysadm 1.21 }
412    
413 sysadm 1.44 if (SYS_conf_reload && !SYS_server_exit)
414 sysadm 1.19 {
415 sysadm 1.44 SYS_conf_reload = 0;
416 sysadm 1.37 sd_notify(0, "RELOADING=1");
417 sysadm 1.30
418 sysadm 1.44 // Reload configuration
419     if (load_conf(CONF_BBSD) < 0)
420     {
421     log_error("Reload conf failed\n");
422     }
423    
424 sysadm 1.34 p_bbs_menu_new = calloc(1, sizeof(MENU_SET));
425     if (p_bbs_menu_new == NULL)
426     {
427     log_error("OOM: calloc(MENU_SET)\n");
428     }
429     else if (load_menu(p_bbs_menu_new, CONF_MENU) < 0)
430     {
431     unload_menu(p_bbs_menu_new);
432     free(p_bbs_menu_new);
433 sysadm 1.38 p_bbs_menu_new = NULL;
434 sysadm 1.33
435 sysadm 1.19 log_error("Reload menu failed\n");
436     }
437     else
438     {
439 sysadm 1.34 unload_menu(p_bbs_menu);
440     free(p_bbs_menu);
441    
442     p_bbs_menu = p_bbs_menu_new;
443     p_bbs_menu_new = NULL;
444    
445 sysadm 1.49 log_common("Reload menu successfully\n");
446 sysadm 1.19 }
447 sysadm 1.37
448     sd_notify(0, "READY=1");
449 sysadm 1.19 }
450    
451 sysadm 1.35 if (SYS_data_file_reload && !SYS_server_exit)
452     {
453     SYS_data_file_reload = 0;
454 sysadm 1.37 sd_notify(0, "RELOADING=1");
455 sysadm 1.35
456     for (int i = 0; i < data_files_load_startup_count; i++)
457     {
458 sysadm 1.39 if (load_file(data_files_load_startup[i]) < 0)
459 sysadm 1.35 {
460     log_error("load_file_mmap(%s) error\n", data_files_load_startup[i]);
461     }
462     }
463    
464 sysadm 1.49 log_common("Reload data files successfully\n");
465 sysadm 1.37 sd_notify(0, "READY=1");
466 sysadm 1.35 }
467    
468 sysadm 1.42 if (SYS_section_list_reload && !SYS_server_exit)
469     {
470     SYS_section_list_reload = 0;
471    
472     if (section_list_loader_reload() < 0)
473     {
474     log_error("ksection_list_loader_reload() failed\n");
475     }
476     }
477    
478 sysadm 1.25 nfds = epoll_wait(epollfd, events, MAX_EVENTS, 100); // 0.1 second
479 sysadm 1.22
480 sysadm 1.25 if (nfds < 0)
481 sysadm 1.19 {
482     if (errno != EINTR)
483     {
484 sysadm 1.25 log_error("epoll_wait() error (%d)\n", errno);
485     break;
486 sysadm 1.19 }
487     continue;
488     }
489 sysadm 1.13
490 sysadm 1.19 // Stop accept new connection on exit
491     if (SYS_server_exit)
492 sysadm 1.13 {
493     continue;
494     }
495    
496 sysadm 1.25 for (int i = 0; i < nfds; i++)
497 sysadm 1.13 {
498 sysadm 1.52 if (events[i].data.fd == socket_server[0] || events[i].data.fd == socket_server[1])
499 sysadm 1.13 {
500 sysadm 1.53 SSH_v2 = (events[i].data.fd == socket_server[1] ? 1 : 0);
501 sysadm 1.52
502 sysadm 1.29 while (!SYS_server_exit) // Accept all incoming connections until error
503 sysadm 1.13 {
504 sysadm 1.52 addrlen = sizeof(sin);
505 sysadm 1.53 socket_client = accept(socket_server[SSH_v2], (struct sockaddr *)&sin, &addrlen);
506 sysadm 1.25 if (socket_client < 0)
507     {
508 sysadm 1.28 if (errno == EAGAIN || errno == EWOULDBLOCK)
509     {
510     break;
511     }
512     else if (errno == EINTR)
513     {
514     continue;
515     }
516     else
517 sysadm 1.25 {
518     log_error("accept(socket_server) error (%d)\n", errno);
519 sysadm 1.28 break;
520 sysadm 1.25 }
521     }
522    
523     strncpy(hostaddr_client, inet_ntoa(sin.sin_addr), sizeof(hostaddr_client) - 1);
524     hostaddr_client[sizeof(hostaddr_client) - 1] = '\0';
525    
526     port_client = ntohs(sin.sin_port);
527    
528 sysadm 1.54 log_common("Accept %sconnection from %s:%d\n", (SSH_v2 ? "" : "SSH2 "), hostaddr_client, port_client);
529 sysadm 1.25
530 sysadm 1.43 if (SYS_child_process_count - 1 < BBS_max_client)
531 sysadm 1.25 {
532 sysadm 1.44 j = 0;
533     for (i = 0; i < BBS_max_client; i++)
534     {
535     if (process_sockaddr_pool[i].pid != 0 && process_sockaddr_pool[i].s_addr == sin.sin_addr.s_addr)
536     {
537     j++;
538     if (j >= BBS_max_client_per_ip)
539     {
540 sysadm 1.50 log_common("Too many client connections (%d) from %s\n", j, hostaddr_client);
541 sysadm 1.44 break;
542     }
543     }
544     }
545    
546     if (j < BBS_max_client_per_ip)
547 sysadm 1.43 {
548 sysadm 1.52 if ((pid = fork_server()) < 0)
549 sysadm 1.44 {
550     log_error("fork_server() error\n");
551     }
552     else if (pid > 0)
553     {
554     i = 0;
555     for (; i < BBS_max_client; i++)
556     {
557     if (process_sockaddr_pool[i].pid == 0)
558     {
559     break;
560     }
561     }
562    
563     if (i >= BBS_max_client)
564     {
565     log_error("Process sockaddr pool depleted\n");
566     }
567     else
568     {
569     process_sockaddr_pool[i].pid = pid;
570     process_sockaddr_pool[i].s_addr = sin.sin_addr.s_addr;
571     }
572     }
573 sysadm 1.43 }
574     }
575     else
576     {
577     log_error("Rejected client connection over limit (%d)\n", SYS_child_process_count - 1);
578 sysadm 1.25 }
579    
580     if (close(socket_client) == -1)
581     {
582     log_error("close(socket_lient) error (%d)\n", errno);
583     }
584 sysadm 1.13 }
585     }
586     }
587 sysadm 1.25 }
588 sysadm 1.13
589 sysadm 1.30 if (close(epollfd) < 0)
590     {
591     log_error("close(epoll) error (%d)\n");
592     }
593    
594 sysadm 1.52 for (i = 0; i < 2; i++)
595     {
596     fcntl(socket_server[i], F_SETFL, flags[i]);
597 sysadm 1.13
598 sysadm 1.52 if (close(socket_server[i]) == -1)
599     {
600     log_error("Close server socket failed\n");
601     }
602 sysadm 1.13 }
603 sysadm 1.7
604 sysadm 1.51 ssh_bind_free(sshbind);
605     ssh_finalize();
606    
607 sysadm 1.13 return 0;
608 sysadm 1.1 }

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