[solanum.git] / ircd / msgbuf.c

/*
 * solanum - an advanced ircd.
 * Copyright (c) 2016 Ariadne Conill <ariadne@dereferenced.org>.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice is present in all copies.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "stdinc.h"
#include "ircd_defs.h"
#include "msgbuf.h"
#include "client.h"
#include "ircd.h"

static const char tag_escape_table[256] = {
	/*        x0   x1   x2   x3   x4   x5   x6   x7   x8   x9   xA   xB   xC   xD   xE   xF */
	/* 0x */   0,   0,   0,   0,   0,   0,   0,   0,   0,   0, 'n',   0,   0, 'r',   0,   0,
	/* 1x */   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
	/* 2x */ 's',   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
	/* 3x */   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0, ':',   0,   0,   0,   0,
	/* 4x */   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
	/* 5x */   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,'\\',   0,   0,   0,
};

static const char tag_unescape_table[256] = {
	/*        x0   x1   x2   x3   x4   x5   x6   x7   x8   x9   xA   xB   xC   xD   xE   xF */
	/* 0x */   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
	/* 1x */   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
	/* 2x */   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
	/* 3x */   0,   0,   0,   0,   0,   0,   0,   0,   0,   0, ';',   0,   0,   0,   0,   0,
	/* 4x */   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
	/* 5x */   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,'\\',   0,   0,   0,
	/* 6x */   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,'\n',   0,
	/* 7x */   0,   0,'\r', ' ',   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
};

static void
msgbuf_unescape_value(char *value)
{
	char *in = value;
	char *out = value;

	if (value == NULL)
		return;

	while (*in != '\0') {
		if (*in == '\\') {
			const char unescape = tag_unescape_table[(unsigned char)*++in];

			/* "\\\0" is unescaped to the character itself, "\0" */
			if (*in == '\0')
				break;

			if (unescape) {
				*out++ = unescape;
				in++;
			} else {
				*out++ = *in++;
			}
		} else {
			*out++ = *in++;
		}
	}

	/* copy final '\0' */
	*out = *in;
}

/*
 * parse a message into a MsgBuf.
 * returns 0 on success, 1 on error.
 */
int
msgbuf_parse(struct MsgBuf *msgbuf, char *line)
{
	char *ch = line;

	msgbuf_init(msgbuf);

	if (*ch == '@') {
		char *t = ch + 1;

		ch = strchr(ch, ' ');

		/* truncate tags if they're too long */
		if ((ch != NULL && (ch - line) + 1 > TAGSLEN) || (ch == NULL && strlen(line) >= TAGSLEN)) {
			ch = &line[TAGSLEN - 1];
		}

		if (ch != NULL) {
			/* NULL terminate the tags string */
			*ch++ = '\0';

			while (1) {
				char *next = strchr(t, ';');
				char *eq = strchr(t, '=');

				if (next != NULL) {
					*next = '\0';

					if (eq > next)
						eq = NULL;
				}

				if (eq != NULL)
					*eq++ = '\0';

				if (*t != '\0') {
					msgbuf_unescape_value(eq);
					msgbuf_append_tag(msgbuf, t, eq, 0);
				}

				if (next != NULL) {
					t = next + 1;
				} else {
					break;
				}
			}
		} else {
			return 1;
		}
	}

	/* truncate message if it's too long */
	if (strlen(ch) > DATALEN) {
		ch[DATALEN] = '\0';
	}

	if (*ch == ':') {
		ch++;
		msgbuf->origin = ch;

		char *end = strchr(ch, ' ');
		if (end == NULL)
			return 4;

		*end = '\0';
		ch = end + 1;
	}

	if (*ch == '\0')
		return 2;

	msgbuf->endp = &ch[strlen(ch)];
	msgbuf->n_para = rb_string_to_array(ch, (char **)msgbuf->para, MAXPARA);
	if (msgbuf->n_para == 0)
		return 3;

	msgbuf->cmd = msgbuf->para[0];
	return 0;
}

/*
 * Unparse the tail of a msgbuf perfectly, preserving framing details
 * msgbuf->para[n] will reach to the end of the line
 */

void
msgbuf_reconstruct_tail(struct MsgBuf *msgbuf, size_t n)
{
	if (msgbuf->endp == NULL || n > msgbuf->n_para)
		return;

	char *c;
	const char *c_;

	if (n == 0)
		c_ = msgbuf->para[n];
	else
		c_ = msgbuf->para[n-1] + strlen(msgbuf->para[n-1]) + 1;

	if (n == msgbuf->n_para && c_ == msgbuf->endp)
		return;

	msgbuf->para[n] = c_;
	/* promote to non-const. msgbuf->endp witnesses that this is allowed */
	c = msgbuf->endp - (msgbuf->endp - c_);

	for ( ; c < msgbuf->endp; c++)
	{
		if (*c == '\0')
			*c = ' ';
	}
}


/*
 * Unparse msgbuf tags into a buffer
 * returns the length of the tags written
 */
static size_t
msgbuf_unparse_tags(char *buf, size_t buflen, const struct MsgBuf *msgbuf, unsigned int capmask)
{
	bool has_tags = false;
	char *commit = buf;
	char *output = buf;
	const char * const end = &buf[buflen - 2]; /* this is where the final ' ' goes */

	for (size_t i = 0; i < msgbuf->n_tags; i++) {
		size_t len;

		if ((msgbuf->tags[i].capmask & capmask) == 0)
			continue;

		if (has_tags) {
			if (output >= end)
				break;
			*output++ = ';';
		} else {
			if (output >= end)
				break;
			*output++ = '@';
		}

		if (msgbuf->tags[i].key == NULL)
			continue;

		len = strlen(msgbuf->tags[i].key);
		if (len == 0)
			continue;

		if (output + len > end)
			break;
		strcat(output, msgbuf->tags[i].key);
		output += len;

		if (msgbuf->tags[i].value != NULL) {
			if (output >= end)
				break;
			*output++ = '=';

			len = strlen(msgbuf->tags[i].value);
			/* this only checks the unescaped length,
			 * but the escaped length could be longer
			 */
			if (output + len > end)
				break;

			for (size_t n = 0; n < len; n++) {
				const unsigned char c = msgbuf->tags[i].value[n];
				const char escape = tag_escape_table[c];

				if (escape) {
					if (output + 2 > end)
						break;

					*output++ = '\\';
					*output++ = escape;
				} else {
					if (output >= end)
						break;

					*output++ = c;
				}
			}
		}

		has_tags = true;
		commit = output;
	}

	if (has_tags)
		*commit++ = ' ';

	*commit = 0;
	return commit - buf;
}

int
msgbuf_unparse_linebuf_tags(char *buf, size_t buflen, void *data)
{
	struct MsgBuf_str_data *str_data = data;

	return msgbuf_unparse_tags(buf, buflen, str_data->msgbuf, str_data->caps);
}

/*
 * unparse a MsgBuf and message prefix into a buffer
 * if origin is NULL, me.name will be used.
 * cmd should not be NULL.
 * updates buflen to correctly allow remaining message data to be added
 */
int
msgbuf_unparse_prefix(char *buf, size_t *buflen, const struct MsgBuf *msgbuf, unsigned int capmask)
{
	size_t tags_buflen;
	size_t used = 0;
	int ret;

	memset(buf, 0, *buflen);

	tags_buflen = *buflen;
	if (tags_buflen > TAGSLEN + 1)
		tags_buflen = TAGSLEN + 1;

	if (msgbuf->n_tags > 0)
		used = msgbuf_unparse_tags(buf, tags_buflen, msgbuf, capmask);

	const size_t data_bufmax = (used + DATALEN + 1);
	if (*buflen > data_bufmax)
		*buflen = data_bufmax;

	ret = rb_snprintf_append(buf, *buflen, ":%s ", msgbuf->origin != NULL ? msgbuf->origin : me.name);
	if (ret > 0)
		used += ret;

	if (msgbuf->cmd != NULL) {
		ret = rb_snprintf_append(buf, *buflen, "%s ", msgbuf->cmd);
		if (ret > 0)
			used += ret;
	}

	if (msgbuf->target != NULL) {
		ret = rb_snprintf_append(buf, *buflen, "%s ", msgbuf->target);
		if (ret > 0)
			used += ret;
	}

	if (used > data_bufmax - 1)
		used = data_bufmax - 1;

	return used;
}

/*
 * unparse a pure MsgBuf into a buffer.
 * if origin is NULL, me.name will be used.
 * cmd should not be NULL.
 * returns 0 on success, 1 on error.
 */
int
msgbuf_unparse(char *buf, size_t buflen, const struct MsgBuf *msgbuf, unsigned int capmask)
{
	size_t buflen_copy = buflen;

	msgbuf_unparse_prefix(buf, &buflen_copy, msgbuf, capmask);

	for (size_t i = 0; i < msgbuf->n_para; i++) {
		const char *fmt;

		if (i == (msgbuf->n_para - 1) && strchr(msgbuf->para[i], ' ') != NULL) {
			fmt = (i == 0) ? ":%s" : " :%s";
		} else {
			fmt = (i == 0) ? "%s" : " %s";
		}

		rb_snprintf_append(buf, buflen_copy, fmt, msgbuf->para[i]);
	}

	return 0;
}

/*
 * unparse a MsgBuf stem + format string into a buffer
 * if origin is NULL, me.name will be used.
 * cmd may not be NULL.
 * returns 0 on success, 1 on error.
 */
int
msgbuf_vunparse_fmt(char *buf, size_t buflen, const struct MsgBuf *head, unsigned int capmask, const char *fmt, va_list va)
{
	size_t buflen_copy = buflen;
	char *ws;
	size_t prefixlen;

	msgbuf_unparse_prefix(buf, &buflen_copy, head, capmask);
	prefixlen = strlen(buf);

	ws = buf + prefixlen;
	vsnprintf(ws, buflen_copy - prefixlen, fmt, va);

	return 0;
}

/*
 * unparse a MsgBuf stem + format string into a buffer (with va_list handling)
 * if origin is NULL, me.name will be used.
 * cmd may not be NULL.
 * returns 0 on success, 1 on error.
 */
int
msgbuf_unparse_fmt(char *buf, size_t buflen, const struct MsgBuf *head, unsigned int capmask, const char *fmt, ...)
{
	va_list va;
	int res;

	va_start(va, fmt);
	res = msgbuf_vunparse_fmt(buf, buflen, head, capmask, fmt, va);
	va_end(va);

	return res;
}

void
msgbuf_cache_init(struct MsgBuf_cache *cache, const struct MsgBuf *msgbuf, const rb_strf_t *message)
{
	cache->msgbuf = msgbuf;
	cache->head = NULL;
	cache->overall_capmask = 0;

	for (size_t i = 0; i < msgbuf->n_tags; i++) {
		cache->overall_capmask |= msgbuf->tags[i].capmask;
	}

	for (int i = 0; i < MSGBUF_CACHE_SIZE; i++) {
		cache->entry[i].caps = 0;
		cache->entry[i].next = NULL;
	}

	rb_fsnprint(cache->message, sizeof(cache->message), message);
}

void
msgbuf_cache_initf(struct MsgBuf_cache *cache, const struct MsgBuf *msgbuf, const rb_strf_t *message, const char *format, ...)
{
	va_list va;
	rb_strf_t strings = { .format = format, .format_args = &va, .next = message };

	va_start(va, format);
	msgbuf_cache_init(cache, msgbuf, &strings);
	va_end(va);
}

buf_head_t*
msgbuf_cache_get(struct MsgBuf_cache *cache, unsigned int caps)
{
	struct MsgBuf_cache_entry *entry = cache->head;
	struct MsgBuf_cache_entry *prev = NULL;
	struct MsgBuf_cache_entry *result = NULL;
	struct MsgBuf_cache_entry *tail = NULL;
	int n = 0;

	caps &= cache->overall_capmask;

	while (entry != NULL) {
		if (entry->caps == caps) {
			/* Cache hit */
			result = entry;
			break;
		}

		tail = prev;
		prev = entry;
		entry = entry->next;
		n++;
	}

	if (result == NULL) {
		if (n < MSGBUF_CACHE_SIZE) {
			/* Cache miss, allocate a new entry */
			result = &cache->entry[n];
			prev = NULL;
		} else {
			/* Cache full, replace the last entry */
			result = prev;
			if (tail != NULL)
				tail->next = NULL;
			prev = NULL;

			rb_linebuf_donebuf(&result->linebuf);
		}

		/* Construct the line using the tags followed by the no tags line */
		struct MsgBuf_str_data msgbuf_str_data = { .msgbuf = cache->msgbuf, .caps = caps };
		rb_strf_t strings[2] = {
			{ .func = msgbuf_unparse_linebuf_tags, .func_args = &msgbuf_str_data, .length = TAGSLEN + 1, .next = &strings[1] },
			{ .format = cache->message, .length = DATALEN + 1, .next = NULL }
		};

		result->caps = caps;
		rb_linebuf_newbuf(&result->linebuf);
		rb_linebuf_put(&result->linebuf, &strings[0]);
	}

	/* Move it to the top */
	if (cache->head != result) {
		if (prev != NULL) {
			prev->next = result->next;
		}
		result->next = cache->head;
		cache->head = result;
	}

	return &result->linebuf;
}

void
msgbuf_cache_free(struct MsgBuf_cache *cache)
{
	struct MsgBuf_cache_entry *entry = cache->head;

	while (entry != NULL) {
		rb_linebuf_donebuf(&entry->linebuf);
		entry = entry->next;
	}

	cache->head = NULL;
}
Commit	Line	Data
a8e69f5d	1	/*
a6f63a82	2	* solanum - an advanced ircd.
3fc0499e	3	* Copyright (c) 2016 Ariadne Conill <ariadne@dereferenced.org>.
a8e69f5d AC	4	*
	5	* Permission to use, copy, modify, and/or distribute this software for any
	6	* purpose with or without fee is hereby granted, provided that the above
	7	* copyright notice and this permission notice is present in all copies.
	8	*
	9	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	10	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
	11	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	12	* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
	13	* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
	14	* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
	15	* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	16	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	17	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
	18	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	19	* POSSIBILITY OF SUCH DAMAGE.
	20	*/
	21
	22	#include "stdinc.h"
	23	#include "ircd_defs.h"
	24	#include "msgbuf.h"
691adddd AC	25	#include "client.h"
691adddd AC	26	#include "ircd.h"
a8e69f5d	27
f3564f47 SA	28	static const char tag_escape_table[256] = {
	29	/* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */
	30	/* 0x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 'n', 0, 0, 'r', 0, 0,
	31	/* 1x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	32	/* 2x */ 's', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	33	/* 3x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ':', 0, 0, 0, 0,
	34	/* 4x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	35	/* 5x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,'\\', 0, 0, 0,
	36	};
	37
	38	static const char tag_unescape_table[256] = {
	39	/* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */
	40	/* 0x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	41	/* 1x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	42	/* 2x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	43	/* 3x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ';', 0, 0, 0, 0, 0,
	44	/* 4x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	45	/* 5x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,'\\', 0, 0, 0,
	46	/* 6x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,'\n', 0,
	47	/* 7x */ 0, 0,'\r', ' ', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	48	};
	49
	50	static void
	51	msgbuf_unescape_value(char *value)
	52	{
	53	char *in = value;
	54	char *out = value;
	55
	56	if (value == NULL)
	57	return;
	58
	59	while (*in != '\0') {
	60	if (*in == '\\') {
	61	const char unescape = tag_unescape_table[(unsigned char)*++in];
	62
	63	/* "\\\0" is unescaped to the character itself, "\0" */
	64	if (*in == '\0')
	65	break;
	66
	67	if (unescape) {
	68	*out++ = unescape;
05a16d98	69	in++;
f3564f47 SA	70	} else {
	71	out++ = in++;
	72	}
	73	} else {
	74	out++ = in++;
	75	}
	76	}
	77
	78	/* copy final '\0' */
	79	out = in;
	80	}
	81
a8e69f5d AC	82	/*
	83	* parse a message into a MsgBuf.
	84	* returns 0 on success, 1 on error.
	85	*/
	86	int
	87	msgbuf_parse(struct MsgBuf msgbuf, char line)
	88	{
f3564f47	89	char *ch = line;
a8e69f5d AC	90
	91	msgbuf_init(msgbuf);
	92
f3564f47	93	if (*ch == '@') {
08006c16	94	char *t = ch + 1;
a8e69f5d AC	95
a8e69f5d AC	96	ch = strchr(ch, ' ');
f3564f47 SA	97
	98	/* truncate tags if they're too long */
	99	if ((ch != NULL && (ch - line) + 1 > TAGSLEN) \|\| (ch == NULL && strlen(line) >= TAGSLEN)) {
	100	ch = &line[TAGSLEN - 1];
	101	}
	102
	103	if (ch != NULL) {
	104	/* NULL terminate the tags string */
	105	*ch++ = '\0';
	106
	107	while (1) {
a8e69f5d AC	108	char *next = strchr(t, ';');
	109	char *eq = strchr(t, '=');
	110
f3564f47	111	if (next != NULL) {
a8e69f5d AC	112	*next = '\0';
a8e69f5d AC	113
08006c16 AC	114	if (eq > next)
	115	eq = NULL;
	116	}
a8e69f5d AC	117
a8e69f5d AC	118	if (eq != NULL)
08006c16	119	*eq++ = '\0';
a8e69f5d	120
f3564f47 SA	121	if (*t != '\0') {
f3564f47 SA	122	msgbuf_unescape_value(eq);
d670fe52	123	msgbuf_append_tag(msgbuf, t, eq, 0);
f3564f47	124	}
269dd686	125
f3564f47	126	if (next != NULL) {
269dd686	127	t = next + 1;
f3564f47	128	} else {
269dd686	129	break;
f3564f47	130	}
a8e69f5d	131	}
f3564f47 SA	132	} else {
f3564f47 SA	133	return 1;
a8e69f5d AC	134	}
	135	}
	136
f3564f47 SA	137	/* truncate message if it's too long */
	138	if (strlen(ch) > DATALEN) {
	139	ch[DATALEN] = '\0';
	140	}
a8e69f5d	141
f3564f47	142	if (*ch == ':') {
a8e69f5d AC	143	ch++;
	144	msgbuf->origin = ch;
	145
	146	char *end = strchr(ch, ' ');
	147	if (end == NULL)
f3564f47	148	return 4;
a8e69f5d AC	149
a8e69f5d AC	150	*end = '\0';
f3564f47	151	ch = end + 1;
a8e69f5d AC	152	}
	153
	154	if (*ch == '\0')
f3564f47	155	return 2;
a8e69f5d	156
4e14f9a4	157	msgbuf->endp = &ch[strlen(ch)];
33ded5fc SA	158	msgbuf->n_para = rb_string_to_array(ch, (char **)msgbuf->para, MAXPARA);
33ded5fc SA	159	if (msgbuf->n_para == 0)
f3564f47	160	return 3;
a8e69f5d	161
33ded5fc	162	msgbuf->cmd = msgbuf->para[0];
a8e69f5d AC	163	return 0;
a8e69f5d AC	164	}
4a13e3f1	165
4e14f9a4 EK	166	/*
	167	* Unparse the tail of a msgbuf perfectly, preserving framing details
	168	* msgbuf->para[n] will reach to the end of the line
	169	*/
	170
	171	void
	172	msgbuf_reconstruct_tail(struct MsgBuf *msgbuf, size_t n)
	173	{
	174	if (msgbuf->endp == NULL \|\| n > msgbuf->n_para)
	175	return;
	176
	177	char *c;
	178	const char *c_;
	179
	180	if (n == 0)
	181	c_ = msgbuf->para[n];
	182	else
	183	c_ = msgbuf->para[n-1] + strlen(msgbuf->para[n-1]) + 1;
	184
	185	if (n == msgbuf->n_para && c_ == msgbuf->endp)
	186	return;
	187
	188	msgbuf->para[n] = c_;
	189	/* promote to non-const. msgbuf->endp witnesses that this is allowed */
	190	c = msgbuf->endp - (msgbuf->endp - c_);
	191
	192	for ( ; c < msgbuf->endp; c++)
	193	{
	194	if (*c == '\0')
	195	*c = ' ';
	196	}
	197	}
	198
	199
f3564f47 SA	200	/*
	201	* Unparse msgbuf tags into a buffer
	202	* returns the length of the tags written
	203	*/
	204	static size_t
	205	msgbuf_unparse_tags(char buf, size_t buflen, const struct MsgBuf msgbuf, unsigned int capmask)
4a13e3f1	206	{
57dd2c6a	207	bool has_tags = false;
f3564f47 SA	208	char *commit = buf;
	209	char *output = buf;
	210	const char * const end = &buf[buflen - 2]; /* this is where the final ' ' goes */
	211
	212	for (size_t i = 0; i < msgbuf->n_tags; i++) {
	213	size_t len;
4a13e3f1	214
4a13e3f1 AC	215	if ((msgbuf->tags[i].capmask & capmask) == 0)
	216	continue;
	217
57dd2c6a	218	if (has_tags) {
f3564f47 SA	219	if (output >= end)
	220	break;
	221	*output++ = ';';
57dd2c6a	222	} else {
f3564f47 SA	223	if (output >= end)
	224	break;
	225	*output++ = '@';
57dd2c6a	226	}
4a13e3f1	227
f3564f47 SA	228	if (msgbuf->tags[i].key == NULL)
	229	continue;
	230
	231	len = strlen(msgbuf->tags[i].key);
	232	if (len == 0)
	233	continue;
4a13e3f1	234
f3564f47 SA	235	if (output + len > end)
	236	break;
	237	strcat(output, msgbuf->tags[i].key);
	238	output += len;
	239
	240	if (msgbuf->tags[i].value != NULL) {
	241	if (output >= end)
	242	break;
	243	*output++ = '=';
	244
	245	len = strlen(msgbuf->tags[i].value);
	246	/* this only checks the unescaped length,
	247	* but the escaped length could be longer
	248	*/
	249	if (output + len > end)
	250	break;
	251
	252	for (size_t n = 0; n < len; n++) {
	253	const unsigned char c = msgbuf->tags[i].value[n];
	254	const char escape = tag_escape_table[c];
	255
	256	if (escape) {
	257	if (output + 2 > end)
	258	break;
	259
	260	*output++ = '\\';
	261	*output++ = escape;
	262	} else {
	263	if (output >= end)
	264	break;
	265
	266	*output++ = c;
	267	}
	268	}
4a13e3f1	269	}
f3564f47 SA	270
	271	has_tags = true;
	272	commit = output;
4a13e3f1 AC	273	}
4a13e3f1 AC	274
57dd2c6a	275	if (has_tags)
f3564f47 SA	276	*commit++ = ' ';
	277
	278	*commit = 0;
	279	return commit - buf;
4a13e3f1 AC	280	}
4a13e3f1 AC	281
4b1cce65 SA	282	int
	283	msgbuf_unparse_linebuf_tags(char buf, size_t buflen, void data)
	284	{
	285	struct MsgBuf_str_data *str_data = data;
	286
	287	return msgbuf_unparse_tags(buf, buflen, str_data->msgbuf, str_data->caps);
	288	}
	289
f3564f47 SA	290	/*
	291	* unparse a MsgBuf and message prefix into a buffer
	292	* if origin is NULL, me.name will be used.
	293	* cmd should not be NULL.
	294	* updates buflen to correctly allow remaining message data to be added
	295	*/
4b1cce65	296	int
f3564f47	297	msgbuf_unparse_prefix(char buf, size_t buflen, const struct MsgBuf *msgbuf, unsigned int capmask)
4a13e3f1	298	{
f3564f47	299	size_t tags_buflen;
4b1cce65 SA	300	size_t used = 0;
4b1cce65 SA	301	int ret;
f3564f47 SA	302
	303	memset(buf, 0, *buflen);
	304
	305	tags_buflen = *buflen;
	306	if (tags_buflen > TAGSLEN + 1)
	307	tags_buflen = TAGSLEN + 1;
4a13e3f1 AC	308
4a13e3f1 AC	309	if (msgbuf->n_tags > 0)
4b1cce65	310	used = msgbuf_unparse_tags(buf, tags_buflen, msgbuf, capmask);
f3564f47	311
4b1cce65	312	const size_t data_bufmax = (used + DATALEN + 1);
f3564f47 SA	313	if (*buflen > data_bufmax)
f3564f47 SA	314	*buflen = data_bufmax;
4a13e3f1	315
4b1cce65 SA	316	ret = rb_snprintf_append(buf, *buflen, ":%s ", msgbuf->origin != NULL ? msgbuf->origin : me.name);
	317	if (ret > 0)
	318	used += ret;
5559c3cf	319
4b1cce65 SA	320	if (msgbuf->cmd != NULL) {
	321	ret = rb_snprintf_append(buf, *buflen, "%s ", msgbuf->cmd);
	322	if (ret > 0)
	323	used += ret;
	324	}
	325
	326	if (msgbuf->target != NULL) {
	327	ret = rb_snprintf_append(buf, *buflen, "%s ", msgbuf->target);
	328	if (ret > 0)
	329	used += ret;
	330	}
	331
	332	if (used > data_bufmax - 1)
	333	used = data_bufmax - 1;
71c875fb	334
4b1cce65	335	return used;
4a13e3f1 AC	336	}
	337
	338	/*
	339	* unparse a pure MsgBuf into a buffer.
	340	* if origin is NULL, me.name will be used.
f3564f47	341	* cmd should not be NULL.
4a13e3f1 AC	342	* returns 0 on success, 1 on error.
	343	*/
	344	int
f3564f47	345	msgbuf_unparse(char buf, size_t buflen, const struct MsgBuf msgbuf, unsigned int capmask)
4a13e3f1	346	{
f3564f47 SA	347	size_t buflen_copy = buflen;
	348
	349	msgbuf_unparse_prefix(buf, &buflen_copy, msgbuf, capmask);
	350
	351	for (size_t i = 0; i < msgbuf->n_para; i++) {
	352	const char *fmt;
	353
	354	if (i == (msgbuf->n_para - 1) && strchr(msgbuf->para[i], ' ') != NULL) {
	355	fmt = (i == 0) ? ":%s" : " :%s";
	356	} else {
	357	fmt = (i == 0) ? "%s" : " %s";
4a13e3f1	358	}
f3564f47 SA	359
f3564f47 SA	360	rb_snprintf_append(buf, buflen_copy, fmt, msgbuf->para[i]);
4a13e3f1 AC	361	}
	362
	363	return 0;
	364	}
8f64d325 AC	365
	366	/*
	367	* unparse a MsgBuf stem + format string into a buffer
	368	* if origin is NULL, me.name will be used.
	369	* cmd may not be NULL.
	370	* returns 0 on success, 1 on error.
	371	*/
	372	int
f3564f47	373	msgbuf_vunparse_fmt(char buf, size_t buflen, const struct MsgBuf head, unsigned int capmask, const char *fmt, va_list va)
8f64d325	374	{
f3564f47	375	size_t buflen_copy = buflen;
8f64d325 AC	376	char *ws;
	377	size_t prefixlen;
	378
f3564f47	379	msgbuf_unparse_prefix(buf, &buflen_copy, head, capmask);
8f64d325 AC	380	prefixlen = strlen(buf);
	381
	382	ws = buf + prefixlen;
f3564f47	383	vsnprintf(ws, buflen_copy - prefixlen, fmt, va);
8f64d325 AC	384
	385	return 0;
	386	}
	387
	388	/*
	389	* unparse a MsgBuf stem + format string into a buffer (with va_list handling)
	390	* if origin is NULL, me.name will be used.
	391	* cmd may not be NULL.
	392	* returns 0 on success, 1 on error.
	393	*/
	394	int
f3564f47	395	msgbuf_unparse_fmt(char buf, size_t buflen, const struct MsgBuf head, unsigned int capmask, const char *fmt, ...)
8f64d325 AC	396	{
	397	va_list va;
	398	int res;
	399
	400	va_start(va, fmt);
	401	res = msgbuf_vunparse_fmt(buf, buflen, head, capmask, fmt, va);
	402	va_end(va);
	403
	404	return res;
	405	}
4b1cce65 SA	406
	407	void
	408	msgbuf_cache_init(struct MsgBuf_cache cache, const struct MsgBuf msgbuf, const rb_strf_t *message)
	409	{
	410	cache->msgbuf = msgbuf;
	411	cache->head = NULL;
	412	cache->overall_capmask = 0;
	413
	414	for (size_t i = 0; i < msgbuf->n_tags; i++) {
	415	cache->overall_capmask \|= msgbuf->tags[i].capmask;
	416	}
	417
	418	for (int i = 0; i < MSGBUF_CACHE_SIZE; i++) {
	419	cache->entry[i].caps = 0;
	420	cache->entry[i].next = NULL;
	421	}
	422
	423	rb_fsnprint(cache->message, sizeof(cache->message), message);
	424	}
	425
	426	void
	427	msgbuf_cache_initf(struct MsgBuf_cache cache, const struct MsgBuf msgbuf, const rb_strf_t message, const char format, ...)
	428	{
	429	va_list va;
	430	rb_strf_t strings = { .format = format, .format_args = &va, .next = message };
	431
	432	va_start(va, format);
	433	msgbuf_cache_init(cache, msgbuf, &strings);
	434	va_end(va);
	435	}
	436
	437	buf_head_t*
	438	msgbuf_cache_get(struct MsgBuf_cache *cache, unsigned int caps)
	439	{
	440	struct MsgBuf_cache_entry *entry = cache->head;
	441	struct MsgBuf_cache_entry *prev = NULL;
	442	struct MsgBuf_cache_entry *result = NULL;
888d20da	443	struct MsgBuf_cache_entry *tail = NULL;
4b1cce65 SA	444	int n = 0;
4b1cce65 SA	445
d5e424bc EK	446	caps &= cache->overall_capmask;
d5e424bc EK	447
4b1cce65 SA	448	while (entry != NULL) {
	449	if (entry->caps == caps) {
	450	/* Cache hit */
	451	result = entry;
	452	break;
	453	}
	454
888d20da	455	tail = prev;
4b1cce65 SA	456	prev = entry;
	457	entry = entry->next;
	458	n++;
	459	}
	460
	461	if (result == NULL) {
	462	if (n < MSGBUF_CACHE_SIZE) {
	463	/* Cache miss, allocate a new entry */
	464	result = &cache->entry[n];
	465	prev = NULL;
	466	} else {
	467	/* Cache full, replace the last entry */
	468	result = prev;
888d20da EK	469	if (tail != NULL)
888d20da EK	470	tail->next = NULL;
4b1cce65 SA	471	prev = NULL;
	472
	473	rb_linebuf_donebuf(&result->linebuf);
	474	}
	475
	476	/* Construct the line using the tags followed by the no tags line */
	477	struct MsgBuf_str_data msgbuf_str_data = { .msgbuf = cache->msgbuf, .caps = caps };
	478	rb_strf_t strings[2] = {
	479	{ .func = msgbuf_unparse_linebuf_tags, .func_args = &msgbuf_str_data, .length = TAGSLEN + 1, .next = &strings[1] },
	480	{ .format = cache->message, .length = DATALEN + 1, .next = NULL }
	481	};
	482
	483	result->caps = caps;
	484	rb_linebuf_newbuf(&result->linebuf);
	485	rb_linebuf_put(&result->linebuf, &strings[0]);
	486	}
	487
	488	/* Move it to the top */
	489	if (cache->head != result) {
	490	if (prev != NULL) {
	491	prev->next = result->next;
	492	}
	493	result->next = cache->head;
	494	cache->head = result;
	495	}
	496
	497	return &result->linebuf;
	498	}
	499
	500	void
	501	msgbuf_cache_free(struct MsgBuf_cache *cache)
	502	{
	503	struct MsgBuf_cache_entry *entry = cache->head;
	504
	505	while (entry != NULL) {
	506	rb_linebuf_donebuf(&entry->linebuf);
	507	entry = entry->next;
	508	}
	509
	510	cache->head = NULL;
	511	}