msgbuf: correctly split buffers into IRCv3 tags and RFC1459 message data

This commit is contained in:
Simon Arlott 2017-06-28 21:24:10 +01:00
parent 9f46eae691
commit f3564f47f4
No known key found for this signature in database
GPG key ID: C8975F2043CA5D24
6 changed files with 207 additions and 92 deletions

View file

@ -43,7 +43,6 @@ struct Blacklist;
#define HOSTIPLEN 53 /* sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255.ipv6") */
#define PASSWDLEN 128
#define CIPHERKEYLEN 64 /* 512bit */
#define CLIENT_BUFSIZE 512 /* must be at least 512 bytes */
#define IDLEN 10

View file

@ -89,7 +89,10 @@
/* 23+1 for \0 */
#define KEYLEN 24
#define TAGSLEN 512 /* IRCv3 message tags */
#define DATALEN 510 /* RFC1459 message data */
#define BUFSIZE 512 /* WARNING: *DONT* CHANGE THIS!!!! */
#define EXT_BUFSIZE (TAGSLEN + DATALEN + 1)
#define OPERNICKLEN (NICKLEN*2) /* Length of OPERNICKs. */
#define USERHOST_REPLYLEN (NICKLEN+HOSTLEN+USERLEN+5)

View file

@ -55,7 +55,7 @@ int msgbuf_parse(struct MsgBuf *msgbuf, char *line);
* cmd may not be NULL.
* returns 0 on success, 1 on error.
*/
int msgbuf_unparse(char *buf, size_t buflen, struct MsgBuf *msgbuf, unsigned int capmask);
int msgbuf_unparse(char *buf, size_t buflen, const struct MsgBuf *msgbuf, unsigned int capmask);
/*
* unparse a MsgBuf header plus payload into a buffer.
@ -63,10 +63,10 @@ int msgbuf_unparse(char *buf, size_t buflen, struct MsgBuf *msgbuf, unsigned int
* cmd may not be NULL.
* returns 0 on success, 1 on error.
*/
int msgbuf_unparse_fmt(char *buf, size_t buflen, struct MsgBuf *head, unsigned int capmask, const char *fmt, ...) AFP(5, 6);
int msgbuf_vunparse_fmt(char *buf, size_t buflen, struct MsgBuf *head, unsigned int capmask, const char *fmt, va_list va);
int msgbuf_unparse_fmt(char *buf, size_t buflen, const struct MsgBuf *head, unsigned int capmask, const char *fmt, ...) AFP(5, 6);
int msgbuf_vunparse_fmt(char *buf, size_t buflen, const struct MsgBuf *head, unsigned int capmask, const char *fmt, va_list va);
void msgbuf_unparse_prefix(char *buf, size_t buflen, struct MsgBuf *msgbuf, unsigned int capmask);
void msgbuf_unparse_prefix(char *buf, size_t *buflen, const struct MsgBuf *msgbuf, unsigned int capmask);
static inline void
msgbuf_init(struct MsgBuf *msgbuf)
@ -85,13 +85,4 @@ msgbuf_append_tag(struct MsgBuf *msgbuf, const char *key, const char *value, uns
}
}
static inline void
msgbuf_append_para(struct MsgBuf *msgbuf, const char *para)
{
if (msgbuf->n_para < MAXPARA) {
msgbuf->para[msgbuf->n_para] = para;
msgbuf->n_para++;
}
}
#endif

View file

@ -25,6 +25,60 @@
#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.
@ -32,29 +86,29 @@
int
msgbuf_parse(struct MsgBuf *msgbuf, char *line)
{
char *ch;
char *parv[MAXPARA];
/* skip any leading spaces */
for (ch = line; *ch && *ch == ' '; ch++)
;
char *ch = line;
msgbuf_init(msgbuf);
if (*ch == '@')
{
if (*ch == '@') {
char *t = ch + 1;
ch = strchr(ch, ' ');
if (ch != NULL)
{
while (1)
{
/* 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)
{
if (next != NULL) {
*next = '\0';
if (eq > next)
@ -64,123 +118,189 @@ msgbuf_parse(struct MsgBuf *msgbuf, char *line)
if (eq != NULL)
*eq++ = '\0';
if (*t && *t != ' ')
if (*t != '\0') {
msgbuf_unescape_value(eq);
msgbuf_append_tag(msgbuf, t, eq, 0);
else
break;
}
if (next != NULL)
if (next != NULL) {
t = next + 1;
else
} else {
break;
}
*ch++ = '\0';
}
else
ch = t;
} else {
return 1;
}
}
/* skip any whitespace between tags and origin */
for (; *ch && *ch == ' '; ch++)
;
/* truncate message if it's too long */
if (strlen(ch) > DATALEN) {
ch[DATALEN] = '\0';
}
if (*ch == ':')
{
if (*ch == ':') {
ch++;
msgbuf->origin = ch;
char *end = strchr(ch, ' ');
if (end == NULL)
return 1;
return 4;
*end = '\0';
for (ch = end + 1; *ch && *ch == ' '; ch++)
;
ch = end + 1;
}
if (*ch == '\0')
return 1;
return 2;
msgbuf->n_para = rb_string_to_array(ch, (char **)msgbuf->para, MAXPARA);
if (msgbuf->n_para == 0)
return 1;
return 3;
msgbuf->cmd = msgbuf->para[0];
return 0;
}
static void
msgbuf_unparse_tags(char *buf, size_t buflen, struct MsgBuf *msgbuf, unsigned int capmask)
/*
* 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;
for (size_t i = 0; i < msgbuf->n_tags; i++)
{
if ((msgbuf->tags[i].capmask & capmask) == 0)
continue;
if (has_tags) {
rb_strlcat(buf, ";", buflen);
if (output >= end)
break;
*output++ = ';';
} else {
*buf = '@';
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;
}
rb_strlcat(buf, msgbuf->tags[i].key, buflen);
/* XXX properly handle escaping */
if (msgbuf->tags[i].value)
{
rb_strlcat(buf, "=", buflen);
rb_strlcat(buf, msgbuf->tags[i].value, buflen);
}
commit = output;
}
if (has_tags)
rb_strlcat(buf, " ", buflen);
*commit++ = ' ';
*commit = 0;
return commit - buf;
}
/*
* 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
*/
void
msgbuf_unparse_prefix(char *buf, size_t buflen, struct MsgBuf *msgbuf, unsigned int capmask)
msgbuf_unparse_prefix(char *buf, size_t *buflen, const struct MsgBuf *msgbuf, unsigned int capmask)
{
memset(buf, 0, buflen);
size_t tags_buflen;
size_t tags_used = 0;
memset(buf, 0, *buflen);
tags_buflen = *buflen;
if (tags_buflen > TAGSLEN + 1)
tags_buflen = TAGSLEN + 1;
if (msgbuf->n_tags > 0)
msgbuf_unparse_tags(buf, buflen, msgbuf, capmask);
tags_used = msgbuf_unparse_tags(buf, tags_buflen, msgbuf, capmask);
rb_snprintf_append(buf, buflen, ":%s ", msgbuf->origin != NULL ? msgbuf->origin : me.name);
const size_t data_bufmax = (tags_used + DATALEN + 1);
if (*buflen > data_bufmax)
*buflen = data_bufmax;
rb_snprintf_append(buf, *buflen, ":%s ", msgbuf->origin != NULL ? msgbuf->origin : me.name);
if (msgbuf->cmd != NULL)
rb_snprintf_append(buf, buflen, "%s ", msgbuf->cmd);
rb_snprintf_append(buf, *buflen, "%s ", msgbuf->cmd);
if (msgbuf->target != NULL)
rb_snprintf_append(buf, buflen, "%s ", msgbuf->target);
rb_snprintf_append(buf, *buflen, "%s ", msgbuf->target);
}
/*
* unparse a pure MsgBuf into a buffer.
* if origin is NULL, me.name will be used.
* cmd may not be NULL.
* cmd should not be NULL.
* returns 0 on success, 1 on error.
*/
int
msgbuf_unparse(char *buf, size_t buflen, struct MsgBuf *msgbuf, unsigned int capmask)
msgbuf_unparse(char *buf, size_t buflen, const struct MsgBuf *msgbuf, unsigned int capmask)
{
msgbuf_unparse_prefix(buf, buflen, msgbuf, capmask);
size_t buflen_copy = buflen;
for (size_t i = msgbuf->cmd != NULL ? 0 : 1; i < msgbuf->n_para; i++)
{
if (i == (msgbuf->n_para - 1))
{
if (strchr(msgbuf->para[i], ' ') != NULL)
rb_snprintf_append(buf, buflen, ":%s", msgbuf->para[i]);
else
rb_strlcat(buf, msgbuf->para[i], 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";
}
else
rb_strlcat(buf, msgbuf->para[i], buflen);
rb_snprintf_append(buf, buflen_copy, fmt, msgbuf->para[i]);
}
return 0;
@ -193,16 +313,17 @@ msgbuf_unparse(char *buf, size_t buflen, struct MsgBuf *msgbuf, unsigned int cap
* returns 0 on success, 1 on error.
*/
int
msgbuf_vunparse_fmt(char *buf, size_t buflen, struct MsgBuf *head, unsigned int capmask, const char *fmt, va_list va)
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, head, capmask);
msgbuf_unparse_prefix(buf, &buflen_copy, head, capmask);
prefixlen = strlen(buf);
ws = buf + prefixlen;
vsnprintf(ws, buflen - prefixlen, fmt, va);
vsnprintf(ws, buflen_copy - prefixlen, fmt, va);
return 0;
}
@ -214,7 +335,7 @@ msgbuf_vunparse_fmt(char *buf, size_t buflen, struct MsgBuf *head, unsigned int
* returns 0 on success, 1 on error.
*/
int
msgbuf_unparse_fmt(char *buf, size_t buflen, struct MsgBuf *head, unsigned int capmask, const char *fmt, ...)
msgbuf_unparse_fmt(char *buf, size_t buflen, const struct MsgBuf *head, unsigned int capmask, const char *fmt, ...)
{
va_list va;
int res;

View file

@ -57,7 +57,7 @@ int MaxConnectionCount = 1;
int MaxClientCount = 1;
int refresh_user_links = 0;
static char buf[BUFSIZE];
static char buf[EXT_BUFSIZE];
/*
* list of recognized server capabilities. "TS" is not on the list
@ -559,7 +559,7 @@ burst_modes_TS6(struct Client *client_p, struct Channel *chptr,
tlen = strlen(banptr->banstr) + (banptr->forward ? strlen(banptr->forward) + 1 : 0) + 1;
/* uh oh */
if(cur_len + tlen > BUFSIZE - 3)
if(cur_len + tlen > EXT_BUFSIZE - 3)
{
/* the one we're trying to send doesnt fit at all! */
if(cur_len == mlen)
@ -601,7 +601,7 @@ burst_modes_TS6(struct Client *client_p, struct Channel *chptr,
static void
burst_TS6(struct Client *client_p)
{
char ubuf[BUFSIZE];
char ubuf[EXT_BUFSIZE];
struct Client *target_p;
struct Channel *chptr;
struct membership *msptr;
@ -698,7 +698,7 @@ burst_TS6(struct Client *client_p)
if(is_voiced(msptr))
tlen++;
if(cur_len + tlen >= BUFSIZE - 3)
if(cur_len + tlen >= EXT_BUFSIZE - 3)
{
*(t-1) = '\0';
sendto_one(client_p, "%s", buf);
@ -764,7 +764,7 @@ burst_TS6(struct Client *client_p)
const char *
show_capabilities(struct Client *target_p)
{
static char msgbuf[BUFSIZE];
static char msgbuf[EXT_BUFSIZE];
*msgbuf = '\0';

View file

@ -218,10 +218,11 @@ send_queued_write(rb_fde_t *F, void *data)
static void
linebuf_put_msgvbuf(struct MsgBuf *msgbuf, buf_head_t *linebuf, unsigned int capmask, const char *pattern, va_list *va)
{
char buf[BUFSIZE];
char buf[EXT_BUFSIZE];
size_t buflen = sizeof(buf);
rb_linebuf_newbuf(linebuf);
msgbuf_unparse_prefix(buf, sizeof buf, msgbuf, capmask);
msgbuf_unparse_prefix(buf, &buflen, msgbuf, capmask);
rb_linebuf_putprefix(linebuf, pattern, va, buf);
}