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bugfix: using quotes inside a pair of long brackets might lead to par…
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…se failures. this is similar to the issue reported by Dejiang Zhu in #596.
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@agentzh
agentzh committed Nov 9, 2015
1 parent c317742 commit 905d7d0
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Showing 2 changed files with 189 additions and 68 deletions.
169 changes: 110 additions & 59 deletions src/ngx_http_lua_directive.c
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Expand Up @@ -44,25 +44,27 @@ static char *ngx_http_lua_conf_lua_block_parse(ngx_conf_t *cf,
ngx_command_t *cmd);
static ngx_int_t ngx_http_lua_conf_read_lua_token(ngx_conf_t *cf,
ngx_http_lua_block_parser_ctx_t *ctx);
static u_char *ngx_http_lua_strlstrn(u_char *s1, u_char *last, u_char *s2,
size_t n);


struct ngx_http_lua_block_parser_ctx_s {
ngx_uint_t start_line;
int token_len;
int expect_right_lbracket;
};


enum {
FOUND_LEFT_CURLY = 0,
FOUND_RIGHT_CURLY,
FOUND_LEFT_LBRACKET_STR,
FOUND_LBRACKET_STR = FOUND_LEFT_LBRACKET_STR,
FOUND_LEFT_LBRACKET_CMT,
FOUND_LBRACKET_CMT = FOUND_LEFT_LBRACKET_CMT,
FOUND_RIGHT_LBRACKET,
FOUND_COMMENT_LINE,
FOUND_DOUBLE_QUOTED,
FOUND_SINGLE_QUOTED,
FOUND_DONTCARE
FOUND_SINGLE_QUOTED
};


Expand Down Expand Up @@ -1316,7 +1318,6 @@ ngx_http_lua_conf_lua_block_parse(ngx_conf_t *cf, ngx_command_t *cmd)
}

ctx.token_len = 0;
ctx.expect_right_lbracket = 0;
start_line = cf->conf_file->line;

dd("init start line: %d", (int) start_line);
Expand All @@ -1334,9 +1335,6 @@ ngx_http_lua_conf_lua_block_parse(ngx_conf_t *cf, ngx_command_t *cmd)
goto done;

case FOUND_LEFT_CURLY:
if (ctx.expect_right_lbracket) {
break;
}

ctx.start_line = cf->conf_file->line;

Expand All @@ -1352,9 +1350,6 @@ ngx_http_lua_conf_lua_block_parse(ngx_conf_t *cf, ngx_command_t *cmd)
break;

case FOUND_RIGHT_CURLY:
if (ctx.expect_right_lbracket) {
break;
}

level--;
dd("seen block done: level=%d", (int) level);
Expand Down Expand Up @@ -1419,49 +1414,24 @@ ngx_http_lua_conf_lua_block_parse(ngx_conf_t *cf, ngx_command_t *cmd)

break;

case FOUND_LEFT_LBRACKET_STR:
if (ctx.expect_right_lbracket) {
break;
}
case FOUND_LBRACKET_STR:

ctx.expect_right_lbracket = ctx.token_len;
ctx.start_line = cf->conf_file->line;
break;

case FOUND_LEFT_LBRACKET_CMT:
if (ctx.expect_right_lbracket) {
break;
}
case FOUND_LBRACKET_CMT:

ctx.expect_right_lbracket = ctx.token_len - (sizeof("--") - 1);
ctx.start_line = cf->conf_file->line;
break;

case FOUND_RIGHT_LBRACKET:
if (!ctx.expect_right_lbracket) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"unexpected lua closing long-bracket");
goto failed;
}

if (ctx.token_len != ctx.expect_right_lbracket) {
/* unmatched long brackets */
break;
}
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"unexpected lua closing long-bracket");
goto failed;

ctx.expect_right_lbracket = 0;
break;

case FOUND_COMMENT_LINE:
case FOUND_DOUBLE_QUOTED:
case FOUND_SINGLE_QUOTED:
if (ctx.expect_right_lbracket) {
break;
}

break;

case FOUND_DONTCARE:
break;

default:
Expand Down Expand Up @@ -1495,7 +1465,7 @@ ngx_http_lua_conf_read_lua_token(ngx_conf_t *cf,
};
int i, rc;
int ovec[OVEC_SIZE];
u_char *start, ch;
u_char *start, *p, *q, ch;
off_t file_size;
size_t len, buf_size;
ssize_t n, size;
Expand Down Expand Up @@ -1585,20 +1555,74 @@ ngx_http_lua_conf_read_lua_token(ngx_conf_t *cf,
rc = ngx_http_lua_lex(b->pos, b->last - b->pos, ovec);

if (rc < 0) { /* no match */
if (ctx->expect_right_lbracket) {
cf->conf_file->line = ctx->start_line;
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"Lua code block missing the closing "
"long bracket");
cf->conf_file->line = start_line;
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"Lua code block missing the \"}\" "
"character");

return NGX_ERROR;
}

if (rc == FOUND_LEFT_LBRACKET_STR || rc == FOUND_LEFT_LBRACKET_CMT) {

/* we update the line numbers for best error messages when the
* closing long bracket is missing */

for (i = 0; i < ovec[0]; i++) {
ch = b->pos[i];
if (ch == LF) {
cf->conf_file->line++;
}
}

b->pos += ovec[0];
ovec[1] -= ovec[0];
ovec[0] = 0;

if (rc == FOUND_LEFT_LBRACKET_CMT) {
p = &b->pos[2]; /* we skip the leading "--" prefix */
rc = FOUND_LBRACKET_CMT;

} else {
cf->conf_file->line = start_line;
p = b->pos;
rc = FOUND_LBRACKET_STR;
}

/* we temporarily rewrite [=*[ in the input buffer to ]=*] to
* construct the pattern for the corresponding closing long
* bracket without additional buffers. */

ngx_http_lua_assert(p[0] == '[');
p[0] = ']';

ngx_http_lua_assert(b->pos[ovec[1] - 1] == '[');
b->pos[ovec[1] - 1] = ']';

/* search for the corresponding closing bracket */

dd("search pattern for the closing long bracket: \"%.*s\" (len=%d)",
(int) (b->pos + ovec[1] - p), p, (int) (b->pos + ovec[1] - p));

q = ngx_http_lua_strlstrn(b->pos + ovec[1], b->last, p,
b->pos + ovec[1] - p - 1);

if (q == NULL) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"Lua code block missing the \"}\" "
"character");
"Lua code block missing the closing "
"long bracket \"%*s\"",
b->pos + ovec[1] - p, p);
return NGX_ERROR;
}

return NGX_ERROR;
/* restore the original opening long bracket */

p[0] = '[';
b->pos[ovec[1] - 1] = '[';

ovec[1] = q - b->pos + b->pos + ovec[1] - p;

dd("found long bracket token: \"%.*s\"",
(int) (ovec[1] - ovec[0]), b->pos + ovec[0]);
}

for (i = 0; i < ovec[1]; i++) {
Expand All @@ -1608,15 +1632,8 @@ ngx_http_lua_conf_read_lua_token(ngx_conf_t *cf,
}
}

if (ctx->expect_right_lbracket && rc == FOUND_COMMENT_LINE) {
b->pos += ovec[0] + sizeof("--") - 1;
rc = FOUND_DONTCARE;
ctx->token_len = sizeof("--") - 1;

} else {
b->pos += ovec[1];
ctx->token_len = ovec[1] - ovec[0];
}
b->pos += ovec[1];
ctx->token_len = ovec[1] - ovec[0];

break;
}
Expand All @@ -1639,4 +1656,38 @@ ngx_http_lua_conf_read_lua_token(ngx_conf_t *cf,
}


/*
* ngx_http_lua_strlstrn() is intended to search for static substring
* with known length in string until the argument last. The argument n
* must be length of the second substring - 1.
*/

static u_char *
ngx_http_lua_strlstrn(u_char *s1, u_char *last, u_char *s2, size_t n)
{
ngx_uint_t c1, c2;

c2 = (ngx_uint_t) *s2++;
last -= n;

do {
do {
if (s1 >= last) {
return NULL;
}

c1 = (ngx_uint_t) *s1++;

dd("testing char '%c' vs '%c'", (int) c1, (int) c2);

} while (c1 != c2);

dd("testing against pattern \"%.*s\"", (int) n, s2);

} while (ngx_strncmp(s1, s2, n) != 0);

return --s1;
}


/* vi:set ft=c ts=4 sw=4 et fdm=marker: */

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