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Inspect User-Agent header, fixes #3
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1 parent 5274f3e commit e2d3a887606622638757aa45806d15518b3e50f8
@Andreas Jaggi Andreas Jaggi authored on 17 Sep 2011
x-way committed on 17 Sep 2011
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 README
If-Unmodified-Since, If-Modified-Since, Date, Accept-Encoding,
Accept-Language, Accept-Charset, Max-Forwards, If-Match,
If-None-Match, Last-Modified, Content-Length, Expires,
Content-Language, Content-Encoding, Allow, Host, Accept,
Connection, Content-Range
Connection, Content-Range, User-Agent
 
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http://github.com/x-way/ngx_http_header_inspect/issues
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 ngx_http_header_inspect.c
static ngx_int_t ngx_header_inspect_host_header(ngx_header_inspect_loc_conf_t *conf, ngx_log_t *log, ngx_str_t value);
static ngx_int_t ngx_header_inspect_accept_header(ngx_header_inspect_loc_conf_t *conf, ngx_log_t *log, ngx_str_t value);
static ngx_int_t ngx_header_inspect_connection_header(ngx_header_inspect_loc_conf_t *conf, ngx_log_t *log, ngx_str_t value);
static ngx_int_t ngx_header_inspect_contentrange_header(ngx_header_inspect_loc_conf_t *conf, ngx_log_t *log, ngx_str_t value);
static ngx_int_t ngx_header_inspect_useragent_header(ngx_header_inspect_loc_conf_t *conf, ngx_log_t *log, ngx_str_t value);
static ngx_int_t ngx_header_inspect_ifrange_header(ngx_header_inspect_loc_conf_t *conf, ngx_log_t *log, ngx_str_t value);
static ngx_int_t ngx_header_inspect_date_header(ngx_header_inspect_loc_conf_t *conf, ngx_log_t *log, char *header, ngx_str_t value);
static ngx_int_t ngx_header_inspect_process_request(ngx_http_request_t *r);
 
 
return rc;
}
 
static ngx_int_t ngx_header_inspect_useragent_header(ngx_header_inspect_loc_conf_t *conf, ngx_log_t *log, ngx_str_t value) {
ngx_uint_t i = 0;
u_char d;
ngx_int_t rc = NGX_OK;
enum useragent_header_states { UAS_START, UAS_PROD, UAS_SLASH, UAS_VER, UAS_SPACE, UAS_PAREN } state;
 
 
if ( value.len < 1 ) {
if ( conf->log ) {
ngx_log_error(NGX_LOG_ALERT, log, 0, "header_inspect: User-Agent header \"%s\" too short", value.data);
}
return NGX_ERROR;
}
 
state = UAS_START;
for ( i = 0; i < value.len ; i++ ) {
d = value.data[i];
if (
((d >= '0') && (d <= '9')) ||
((d >= 'a') && (d <= 'z')) ||
((d >= 'A') && (d <= 'Z')) ||
(d == '-') || (d == '.')
) {
switch ( state ) {
case UAS_START:
case UAS_SPACE:
state = UAS_PROD;
break;
case UAS_PROD:
case UAS_VER:
case UAS_PAREN:
break;
case UAS_SLASH:
state = UAS_VER;
break;
default:
rc = NGX_ERROR;
}
} else if ( d == '/' ) {
switch ( state ) {
case UAS_PROD:
state = UAS_SLASH;
break;
default:
rc = NGX_ERROR;
}
} else if ( d == ' ' ) {
switch ( state ) {
case UAS_VER:
state = UAS_SPACE;
break;
case UAS_SPACE:
case UAS_PAREN:
break;
default:
rc = NGX_ERROR;
}
} else if ( d == '(' ) {
switch ( state ) {
case UAS_SPACE:
state = UAS_PAREN;
break;
default:
rc = NGX_ERROR;
}
} else if ( d == ')' ) {
switch ( state ) {
case UAS_PAREN:
state = UAS_SPACE;
break;
default:
rc = NGX_ERROR;
}
} else if (
(d == ',') || (d == ':') || (d == ';') ||
(d == '+') || (d == '_')
) {
switch ( state ) {
case UAS_PAREN:
break;
default:
rc = NGX_ERROR;
}
} else {
rc = NGX_ERROR;
}
if ( rc == NGX_ERROR ) {
if ( conf->log ) {
ngx_log_error(NGX_LOG_ALERT, log, 0, "header_inspect: illegal character at position %d in User-Agent header \"%s\"", i, value.data);
}
return NGX_ERROR;
}
}
switch ( state ) {
case UAS_SPACE:
case UAS_PROD:
case UAS_VER:
break;
default:
if ( conf->log ) {
ngx_log_error(NGX_LOG_ALERT, log, 0, "header_inspect: unexpected end of User-Agent header \"%s\"", value.data);
}
return NGX_ERROR;
}
 
return NGX_OK;
}
 
static ngx_int_t ngx_header_inspect_contentrange_header(ngx_header_inspect_loc_conf_t *conf, ngx_log_t *log, ngx_str_t value) {
ngx_uint_t i = 0;
ngx_int_t rc = NGX_OK;
ngx_int_t a,b,c;
rc = ngx_header_inspect_contentrange_header(conf, r->connection->log, h[i].value);
if ((rc != NGX_OK) && conf->block) {
return NGX_HTTP_BAD_REQUEST;
}
} else if ((h[i].key.len == 10) && (ngx_strcmp("User-Agent", h[i].key.data) == 0) ) {
rc = ngx_header_inspect_useragent_header(conf, r->connection->log, h[i].value);
if ((rc != NGX_OK) && conf->block) {
return NGX_HTTP_BAD_REQUEST;
}
} else {
/* TODO: support for other headers */
if (conf->log_uninspected) {
ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0, "header_inspect: uninspected header \"%s: %s\"", h[i].key.data, h[i].value.data);