Annotation of embedaddon/bird/nest/cli.c, revision 1.1.1.1
1.1 misho 1: /*
2: * BIRD Internet Routing Daemon -- Command-Line Interface
3: *
4: * (c) 1999--2000 Martin Mares <mj@ucw.cz>
5: *
6: * Can be freely distributed and used under the terms of the GNU GPL.
7: */
8:
9: /**
10: * DOC: Command line interface
11: *
12: * This module takes care of the BIRD's command-line interface (CLI).
13: * The CLI exists to provide a way to control BIRD remotely and to inspect
14: * its status. It uses a very simple textual protocol over a stream
15: * connection provided by the platform dependent code (on UNIX systems,
16: * it's a UNIX domain socket).
17: *
18: * Each session of the CLI consists of a sequence of request and replies,
19: * slightly resembling the FTP and SMTP protocols.
20: * Requests are commands encoded as a single line of text, replies are
21: * sequences of lines starting with a four-digit code followed by either
22: * a space (if it's the last line of the reply) or a minus sign (when the
23: * reply is going to continue with the next line), the rest of the line
24: * contains a textual message semantics of which depends on the numeric
25: * code. If a reply line has the same code as the previous one and it's
26: * a continuation line, the whole prefix can be replaced by a single
27: * white space character.
28: *
29: * Reply codes starting with 0 stand for `action successfully completed' messages,
30: * 1 means `table entry', 8 `runtime error' and 9 `syntax error'.
31: *
32: * Each CLI session is internally represented by a &cli structure and a
33: * resource pool containing all resources associated with the connection,
34: * so that it can be easily freed whenever the connection gets closed, not depending
35: * on the current state of command processing.
36: *
37: * The CLI commands are declared as a part of the configuration grammar
38: * by using the |CF_CLI| macro. When a command is received, it is processed
39: * by the same lexical analyzer and parser as used for the configuration, but
40: * it's switched to a special mode by prepending a fake token to the text,
41: * so that it uses only the CLI command rules. Then the parser invokes
42: * an execution routine corresponding to the command, which either constructs
43: * the whole reply and returns it back or (in case it expects the reply will be long)
44: * it prints a partial reply and asks the CLI module (using the @cont hook)
45: * to call it again when the output is transferred to the user.
46: *
47: * The @this_cli variable points to a &cli structure of the session being
48: * currently parsed, but it's of course available only in command handlers
49: * not entered using the @cont hook.
50: *
51: * TX buffer management works as follows: At cli.tx_buf there is a
52: * list of TX buffers (struct cli_out), cli.tx_write is the buffer
53: * currently used by the producer (cli_printf(), cli_alloc_out()) and
54: * cli.tx_pos is the buffer currently used by the consumer
55: * (cli_write(), in system dependent code). The producer uses
56: * cli_out.wpos ptr as the current write position and the consumer
57: * uses cli_out.outpos ptr as the current read position. When the
58: * producer produces something, it calls cli_write_trigger(). If there
59: * is not enough space in the current buffer, the producer allocates
60: * the new one. When the consumer processes everything in the buffer
61: * queue, it calls cli_written(), tha frees all buffers (except the
62: * first one) and schedules cli.event .
63: *
64: */
65:
66: #include "nest/bird.h"
67: #include "nest/cli.h"
68: #include "conf/conf.h"
69: #include "lib/string.h"
70:
71: pool *cli_pool;
72:
73: static byte *
74: cli_alloc_out(cli *c, int size)
75: {
76: struct cli_out *o;
77:
78: if (!(o = c->tx_write) || o->wpos + size > o->end)
79: {
80: if (!o && c->tx_buf)
81: o = c->tx_buf;
82: else
83: {
84: o = mb_alloc(c->pool, sizeof(struct cli_out) + CLI_TX_BUF_SIZE);
85: if (c->tx_write)
86: c->tx_write->next = o;
87: else
88: c->tx_buf = o;
89: o->wpos = o->outpos = o->buf;
90: o->end = o->buf + CLI_TX_BUF_SIZE;
91: }
92: c->tx_write = o;
93: if (!c->tx_pos)
94: c->tx_pos = o;
95: o->next = NULL;
96: }
97: o->wpos += size;
98: return o->wpos - size;
99: }
100:
101: /**
102: * cli_printf - send reply to a CLI connection
103: * @c: CLI connection
104: * @code: numeric code of the reply, negative for continuation lines
105: * @msg: a printf()-like formatting string.
106: *
107: * This function send a single line of reply to a given CLI connection.
108: * In works in all aspects like bsprintf() except that it automatically
109: * prepends the reply line prefix.
110: *
111: * Please note that if the connection can be already busy sending some
112: * data in which case cli_printf() stores the output to a temporary buffer,
113: * so please avoid sending a large batch of replies without waiting
114: * for the buffers to be flushed.
115: *
116: * If you want to write to the current CLI output, you can use the cli_msg()
117: * macro instead.
118: */
119: void
120: cli_printf(cli *c, int code, char *msg, ...)
121: {
122: va_list args;
123: byte buf[CLI_LINE_SIZE];
124: int cd = code;
125: int errcode;
126: int size, cnt;
127:
128: if (cd < 0)
129: {
130: cd = -cd;
131: if (cd == c->last_reply)
132: size = bsprintf(buf, " ");
133: else
134: size = bsprintf(buf, "%04d-", cd);
135: errcode = -8000;
136: }
137: else if (cd == CLI_ASYNC_CODE)
138: {
139: size = 1; buf[0] = '+';
140: errcode = cd;
141: }
142: else
143: {
144: size = bsprintf(buf, "%04d ", cd);
145: errcode = 8000;
146: }
147:
148: c->last_reply = cd;
149: va_start(args, msg);
150: cnt = bvsnprintf(buf+size, sizeof(buf)-size-1, msg, args);
151: va_end(args);
152: if (cnt < 0)
153: {
154: cli_printf(c, errcode, "<line overflow>");
155: return;
156: }
157: size += cnt;
158: buf[size++] = '\n';
159: memcpy(cli_alloc_out(c, size), buf, size);
160: }
161:
162: static void
163: cli_copy_message(cli *c)
164: {
165: byte *p, *q;
166: uint cnt = 2;
167:
168: if (c->ring_overflow)
169: {
170: byte buf[64];
171: int n = bsprintf(buf, "<%d messages lost>\n", c->ring_overflow);
172: c->ring_overflow = 0;
173: memcpy(cli_alloc_out(c, n), buf, n);
174: }
175: p = c->ring_read;
176: while (*p)
177: {
178: cnt++;
179: p++;
180: if (p == c->ring_end)
181: p = c->ring_buf;
182: ASSERT(p != c->ring_write);
183: }
184: c->async_msg_size += cnt;
185: q = cli_alloc_out(c, cnt);
186: *q++ = '+';
187: p = c->ring_read;
188: do
189: {
190: *q = *p++;
191: if (p == c->ring_end)
192: p = c->ring_buf;
193: }
194: while (*q++);
195: c->ring_read = p;
196: q[-1] = '\n';
197: }
198:
199: static void
200: cli_hello(cli *c)
201: {
202: cli_printf(c, 1, "BIRD " BIRD_VERSION " ready.");
203: c->cont = NULL;
204: }
205:
206: static void
207: cli_free_out(cli *c)
208: {
209: struct cli_out *o, *p;
210:
211: if (o = c->tx_buf)
212: {
213: o->wpos = o->outpos = o->buf;
214: while (p = o->next)
215: {
216: o->next = p->next;
217: mb_free(p);
218: }
219: }
220: c->tx_write = c->tx_pos = NULL;
221: c->async_msg_size = 0;
222: }
223:
224: void
225: cli_written(cli *c)
226: {
227: cli_free_out(c);
228: ev_schedule(c->event);
229: }
230:
231:
232: static byte *cli_rh_pos;
233: static uint cli_rh_len;
234: static int cli_rh_trick_flag;
235: struct cli *this_cli;
236:
237: static int
238: cli_cmd_read_hook(byte *buf, uint max, UNUSED int fd)
239: {
240: if (!cli_rh_trick_flag)
241: {
242: cli_rh_trick_flag = 1;
243: buf[0] = '!';
244: return 1;
245: }
246: if (max > cli_rh_len)
247: max = cli_rh_len;
248: memcpy(buf, cli_rh_pos, max);
249: cli_rh_pos += max;
250: cli_rh_len -= max;
251: return max;
252: }
253:
254: static void
255: cli_command(struct cli *c)
256: {
257: struct config f;
258: int res;
259:
260: if (config->cli_debug > 1)
261: log(L_TRACE "CLI: %s", c->rx_buf);
262: bzero(&f, sizeof(f));
263: f.mem = c->parser_pool;
264: cf_read_hook = cli_cmd_read_hook;
265: cli_rh_pos = c->rx_buf;
266: cli_rh_len = strlen(c->rx_buf);
267: cli_rh_trick_flag = 0;
268: this_cli = c;
269: lp_flush(c->parser_pool);
270: res = cli_parse(&f);
271: if (!res)
272: cli_printf(c, 9001, f.err_msg);
273: }
274:
275: static void
276: cli_event(void *data)
277: {
278: cli *c = data;
279: int err;
280:
281: while (c->ring_read != c->ring_write &&
282: c->async_msg_size < CLI_MAX_ASYNC_QUEUE)
283: cli_copy_message(c);
284:
285: if (c->tx_pos)
286: ;
287: else if (c->cont)
288: c->cont(c);
289: else
290: {
291: err = cli_get_command(c);
292: if (!err)
293: return;
294: if (err < 0)
295: cli_printf(c, 9000, "Command too long");
296: else
297: cli_command(c);
298: }
299:
300: cli_write_trigger(c);
301: }
302:
303: cli *
304: cli_new(void *priv)
305: {
306: pool *p = rp_new(cli_pool, "CLI");
307: cli *c = mb_alloc(p, sizeof(cli));
308:
309: bzero(c, sizeof(cli));
310: c->pool = p;
311: c->priv = priv;
312: c->event = ev_new(p);
313: c->event->hook = cli_event;
314: c->event->data = c;
315: c->cont = cli_hello;
316: c->parser_pool = lp_new(c->pool, 4096);
317: c->rx_buf = mb_alloc(c->pool, CLI_RX_BUF_SIZE);
318: ev_schedule(c->event);
319: return c;
320: }
321:
322: void
323: cli_kick(cli *c)
324: {
325: if (!c->cont && !c->tx_pos)
326: ev_schedule(c->event);
327: }
328:
329: static list cli_log_hooks;
330: static int cli_log_inited;
331:
332: void
333: cli_set_log_echo(cli *c, uint mask, uint size)
334: {
335: if (c->ring_buf)
336: {
337: mb_free(c->ring_buf);
338: c->ring_buf = c->ring_end = c->ring_read = c->ring_write = NULL;
339: rem_node(&c->n);
340: }
341: c->log_mask = mask;
342: if (mask && size)
343: {
344: c->ring_buf = mb_alloc(c->pool, size);
345: c->ring_end = c->ring_buf + size;
346: c->ring_read = c->ring_write = c->ring_buf;
347: add_tail(&cli_log_hooks, &c->n);
348: c->log_threshold = size / 8;
349: }
350: c->ring_overflow = 0;
351: }
352:
353: void
354: cli_echo(uint class, byte *msg)
355: {
356: unsigned len, free, i, l;
357: cli *c;
358: byte *m;
359:
360: if (!cli_log_inited || EMPTY_LIST(cli_log_hooks))
361: return;
362: len = strlen(msg) + 1;
363: WALK_LIST(c, cli_log_hooks)
364: {
365: if (!(c->log_mask & (1 << class)))
366: continue;
367: if (c->ring_read <= c->ring_write)
368: free = (c->ring_end - c->ring_buf) - (c->ring_write - c->ring_read + 1);
369: else
370: free = c->ring_read - c->ring_write - 1;
371: if ((len > free) ||
372: (free < c->log_threshold && class < (unsigned) L_INFO[0]))
373: {
374: c->ring_overflow++;
375: continue;
376: }
377: if (c->ring_read == c->ring_write)
378: ev_schedule(c->event);
379: m = msg;
380: l = len;
381: while (l)
382: {
383: if (c->ring_read <= c->ring_write)
384: i = c->ring_end - c->ring_write;
385: else
386: i = c->ring_read - c->ring_write;
387: if (i > l)
388: i = l;
389: memcpy(c->ring_write, m, i);
390: m += i;
391: l -= i;
392: c->ring_write += i;
393: if (c->ring_write == c->ring_end)
394: c->ring_write = c->ring_buf;
395: }
396: }
397: }
398:
399: /* Hack for scheduled undo notification */
400: extern cli *cmd_reconfig_stored_cli;
401:
402: void
403: cli_free(cli *c)
404: {
405: cli_set_log_echo(c, 0, 0);
406: if (c->cleanup)
407: c->cleanup(c);
408: if (c == cmd_reconfig_stored_cli)
409: cmd_reconfig_stored_cli = NULL;
410: rfree(c->pool);
411: }
412:
413: /**
414: * cli_init - initialize the CLI module
415: *
416: * This function is called during BIRD startup to initialize
417: * the internal data structures of the CLI module.
418: */
419: void
420: cli_init(void)
421: {
422: cli_pool = rp_new(&root_pool, "CLI");
423: init_list(&cli_log_hooks);
424: cli_log_inited = 1;
425: }
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