/*
* 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, ' ');
if (ch == NULL)
return PARSE_UNTERMINATED_TAGS;
msgbuf->tagslen = ch - line + 1;
/* truncate tags if they're too long */
if (ch - line + 1 > TAGSLEN) {
ch = &line[TAGSLEN - 1];
}
/* 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;
}
}
}
return msgbuf_partial_parse(msgbuf, ch);
}
int
msgbuf_partial_parse(struct MsgBuf *msgbuf, char *line)
{
char *ch = line;
const char *start = ch;
/* 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 PARSE_UNTERMINATED_ORIGIN;
*end = '\0';
ch = end + 1;
}
if (*ch == '\0')
return PARSE_NO_COMMAND;
msgbuf->endp = &ch[strlen(ch)];
msgbuf->n_para = rb_string_to_array(ch, (char **)msgbuf->para, MAXPARA);
if (msgbuf->n_para == 0)
return PARSE_NO_PARAMS;
const char *potential_colon = msgbuf->para[msgbuf->n_para - 1] - 1;
if (potential_colon >= start && *potential_colon == ':')
msgbuf->preserve_trailing = true;
msgbuf->cmd = msgbuf->para[0];
return PARSE_SUCCESS;
}
/*
* 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, uint64_t 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 (int clientonly = 0; clientonly < 2; clientonly++)
{
const char *stop = commit + TAGSPARTLEN + 1;
if (stop > end)
stop = end;
for (size_t i = 0; i < msgbuf->n_tags; i++)
{
output = commit;
if ((msgbuf->tags[i].capmask & capmask) == 0)
continue;
if (msgbuf->tags[i].key == NULL)
continue;
size_t len = strlen(msgbuf->tags[i].key);
if (len == 0 || (len == 1 && *msgbuf->tags[i].key == '+'))
continue;
/* spec requires that server tags are always provided before client-only tags */
if (clientonly ^ (*msgbuf->tags[i].key == '+'))
continue;
if (output + len + 1 > stop)
break;
*output++ = has_tags ? ';' : '@';
strcpy(output, msgbuf->tags[i].key);
output += len;
if (msgbuf->tags[i].value != NULL) {
if (output >= stop)
break;
*output++ = '=';
len = strlen(msgbuf->tags[i].value);
/* this only checks the unescaped length,
* but the escaped length could be longer
*/
if (output + len > stop)
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 > stop)
break;
*output++ = '\\';
*output++ = escape;
} else {
if (output >= stop)
break;
*output++ = c;
}
}
}
has_tags = true;
commit = output;
}
}
if (has_tags)
*commit++ = ' ';
*commit = 0;
return commit - buf;
}
int
msgbuf_unparse_linebuf(char *buf, size_t buflen, void *data)
{
struct MsgBuf_str_data *str_data = data;
size_t used = 0;
int ret;
size_t tags_buflen = buflen;
if (tags_buflen > TAGSLEN + 1)
tags_buflen = TAGSLEN + 1;
/* msgbuf_unparse / msgbuf_unparse_prefix have a couple of undesirable behaviors:
* 1. it enforces a source (using me.name if origin is NULL)
* 2. it adds in the cmd and target if defined (duplicating work done by msgbuf_unparse_para)
*
* As such, just unparse tags directly and then only add in origin if non-NULL
*/
used = msgbuf_unparse_tags(buf, tags_buflen, str_data->msgbuf, str_data->caps);
if (buflen > used + DATALEN + 1)
buflen = used + DATALEN + 1;
if (str_data->msgbuf->origin != NULL)
{
/* rb_snprintf_append returns the complete length of the final string, not just the number of bytes it wrote */
ret = rb_snprintf_append(buf, buflen, ":%s ", str_data->msgbuf->origin);
if (ret > 0)
used = ret;
}
used += msgbuf_unparse_para(buf, buflen, str_data->msgbuf);
return used;
}
int
msgbuf_unparse_linebuf_tags(char *buf, size_t buflen, void *data)
{
struct MsgBuf_str_data *str_data = data;
if (buflen > TAGSLEN + 1)
buflen = TAGSLEN + 1;
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, uint64_t 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;
/* rb_snprintf_append returns the complete length of the final string, not just the number of bytes it wrote */
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;
}
int
msgbuf_unparse_para(char *buf, size_t buflen, const struct MsgBuf *msgbuf)
{
size_t orig_len = strlen(buf);
size_t new_len = orig_len;
int ret;
for (size_t i = 0; i < msgbuf->n_para; i++) {
const char *fmt;
if (i == msgbuf->n_para - 1 && (msgbuf->preserve_trailing || strchr(msgbuf->para[i], ' ') != NULL || *msgbuf->para[i] == ':')) {
fmt = i == 0 ? ":%s" : " :%s";
} else {
fmt = i == 0 ? "%s" : " %s";
}
/* rb_snprintf_append returns the complete length of the final string, not just the number of bytes it wrote */
ret = rb_snprintf_append(buf, buflen, fmt, msgbuf->para[i]);
if (ret > 0)
new_len = ret;
}
if (new_len > buflen - 1)
new_len = buflen - 1;
return new_len - orig_len;
}
/*
* 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, uint64_t capmask)
{
size_t buflen_copy = buflen;
msgbuf_unparse_prefix(buf, &buflen_copy, msgbuf, capmask);
msgbuf_unparse_para(buf, buflen_copy, msgbuf);
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, uint64_t 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, uint64_t 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;
}
const char *
msgbuf_get_tag(const struct MsgBuf *buf, const char *name)
{
for (size_t i = 0; i < buf->n_tags; i++)
{
if (strcmp(name, buf->tags[i].key))
continue;
const char *v = buf->tags[i].value;
return v != NULL ? v : "";
}
return NULL;
}
void
msgbuf_cache_init(struct MsgBuf_cache *cache, struct MsgBuf *msgbuf, const char *local_source, const char *remote_source)
{
const char *orig_source = msgbuf->origin;
struct MsgBuf_str_data data = { .msgbuf = msgbuf, .caps = 0 };
rb_strf_t strings = { .func = msgbuf_unparse_linebuf, .func_args = &data, .length = DATALEN + 1, .next = NULL };
memset(cache, 0, sizeof(struct MsgBuf_cache));
cache->msgbuf = msgbuf;
msgbuf->origin = local_source != NULL ? local_source : orig_source;
rb_fsnprint(cache->local, sizeof(cache->local), &strings);
msgbuf->origin = remote_source != NULL ? remote_source : orig_source;
rb_fsnprint(cache->remote, sizeof(cache->remote), &strings);
msgbuf->origin = orig_source;
for (size_t i = 0; i < msgbuf->n_tags; i++) {
cache->overall_capmask |= msgbuf->tags[i].capmask;
}
}
buf_head_t*
msgbuf_cache_get(struct MsgBuf_cache *cache, uint64_t caps, bool is_remote)
{
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 && entry->is_remote == is_remote) {
/* 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 (already saved) message */
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, .next = &strings[1] },
{ .format = is_remote ? cache->remote : cache->local, .format_args = NULL, .next = NULL },
};
result->caps = caps;
result->is_remote = is_remote;
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;
}
