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#include <nginx.h>
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_string.h>
#include <ngx_table.h>
#include <ngx_hunk.h>
#include <ngx_conf_file.h>
#include <ngx_http.h>
#include <ngx_http_config.h>
#include <ngx_http_write_filter.h>
static void ngx_http_header_filter_init(ngx_pool_t *pool,
ngx_http_conf_filter_t *cf);
static int ngx_http_header_filter(ngx_http_request_t *r);
ngx_http_module_t ngx_http_header_filter_module_ctx = {
NULL, /* create server config */
NULL, /* init server config */
NULL, /* create location config */
NULL, /* merge location config */
ngx_http_header_filter_init /* init filters */
};
ngx_module_t ngx_http_header_filter_module = {
0, /* module index */
&ngx_http_header_filter_module_ctx, /* module context */
NULL, /* module directives */
NGX_HTTP_MODULE_TYPE, /* module type */
NULL /* init module */
};
static char server_string[] = "Server: " NGINX_VER CRLF;
static ngx_str_t http_codes[] = {
ngx_string("200 OK"),
ngx_string("301 Moved Permanently"),
ngx_string("302 Moved Temporarily"),
ngx_null_string, /* 303 */
ngx_string("304 Not Modified"),
ngx_string("400 Bad Request"),
ngx_null_string, /* 401 */
ngx_null_string, /* 402 */
ngx_string("403 Forbidden"),
ngx_string("404 Not Found"),
ngx_null_string, /* 405 */
ngx_null_string, /* 406 */
ngx_null_string, /* 407 */
ngx_string("408 Request Time-out"),
ngx_null_string, /* 409 */
ngx_null_string, /* 410 */
ngx_string("411 Length Required"),
ngx_null_string, /* 412 */
ngx_string("413 Request Entity Too Large"),
ngx_null_string, /* "414 Request-URI Too Large" but we never send it
because we treat such requests as HTTP/0.9 requests
and send only the body without the header */
ngx_null_string, /* 415 */
ngx_string("416 Requested Range Not Satisfiable"),
ngx_string("500 Internal Server Error"),
ngx_string("501 Method Not Implemented"),
ngx_string("502 Bad Gateway"),
ngx_string("503 Service Temporarily Unavailable"),
ngx_string("504 Gateway Time-out")
};
static int ngx_http_header_filter(ngx_http_request_t *r)
{
int len, status, i;
time_t ims;
ngx_hunk_t *h;
ngx_chain_t *ch;
ngx_table_elt_t *header;
if (r->http_version < NGX_HTTP_VERSION_10) {
return NGX_OK;
}
/* 9 is for "HTTP/1.x ", 2 is for trailing "\r\n"
and 2 is for end of header */
len = 9 + 2 + 2;
if (r->headers_in.if_modified_since && r->headers_out.status == NGX_HTTP_OK)
{
/* TODO: check LM header */
if (r->headers_out.last_modified_time) {
ims = ngx_http_parse_time(
r->headers_in.if_modified_since->value.data,
r->headers_in.if_modified_since->value.len);
ngx_log_debug(r->connection->log, "%d %d" _
ims _ r->headers_out.last_modified_time);
/* I think that the date equality is correcter */
if (ims != NGX_ERROR && ims == r->headers_out.last_modified_time) {
r->headers_out.status = NGX_HTTP_NOT_MODIFIED;
r->headers_out.content_length = -1;
r->headers_out.content_type->key.len = 0;
}
}
}
/* status line */
if (r->headers_out.status_line.len) {
len += r->headers_out.status_line.len;
#if (NGX_SUPPRESS_WARN)
status = NGX_INVALID_ARRAY_INDEX;
#endif
} else {
if (r->headers_out.status < NGX_HTTP_MOVED_PERMANENTLY) {
status = r->headers_out.status - NGX_HTTP_OK;
} else if (r->headers_out.status < NGX_HTTP_BAD_REQUEST) {
status = r->headers_out.status - NGX_HTTP_MOVED_PERMANENTLY + 1;
r->header_only = 1;
} else if (r->headers_out.status < NGX_HTTP_INTERNAL_SERVER_ERROR) {
status = r->headers_out.status - NGX_HTTP_BAD_REQUEST + 1 + 4;
} else {
status = r->headers_out.status
- NGX_HTTP_INTERNAL_SERVER_ERROR + 1 + 4 + 17;
}
len += http_codes[status].len;
}
if (r->headers_out.server && r->headers_out.server->key.len) {
len += r->headers_out.server->key.len
+ r->headers_out.server->value.len + 2;
} else {
len += sizeof(server_string) - 1;
}
if (r->headers_out.date && r->headers_out.date->key.len) {
len += r->headers_out.date->key.len
+ r->headers_out.date->value.len + 2;
} else {
/* "Date: ... \r\n"; */
len += 37;
}
/* 2^64 is 20 characters */
if (r->headers_out.content_length >= 0) {
len += 48;
}
#if 0
if (r->headers_out.content_type.len)
len += r->headers_out.content_type.len + 16;
#endif
if (r->headers_out.last_modified && r->headers_out.last_modified->key.len) {
len += r->headers_out.last_modified->key.len
+ r->headers_out.last_modified->value.len + 2;
} else if (r->headers_out.last_modified_time != -1) {
/* "Last-Modified: ... \r\n"; */
len += 46;
}
if (r->keepalive == 0) {
len += 19;
} else {
len += 24;
}
header = (ngx_table_elt_t *) r->headers_out.headers->elts;
for (i = 0; i < r->headers_out.headers->nelts; i++) {
if (header[i].key.len == 0) {
continue;
}
len += header[i].key.len + 2 + header[i].value.len + 2;
}
ngx_test_null(h, ngx_create_temp_hunk(r->pool, len, 0, 64), NGX_ERROR);
/* "HTTP/1.x " */
ngx_memcpy(h->last, "HTTP/1.1 ", 9);
h->last += 9;
/* status line */
if (r->headers_out.status_line.len) {
ngx_memcpy(h->last, r->headers_out.status_line.data,
r->headers_out.status_line.len);
h->last += r->headers_out.status_line.len;
} else {
ngx_memcpy(h->last, http_codes[status].data,
http_codes[status].len);
h->last += http_codes[status].len;
}
*(h->last++) = CR; *(h->last++) = LF;
if (!(r->headers_out.server && r->headers_out.server->key.len)) {
ngx_memcpy(h->last, server_string, sizeof(server_string) - 1);
h->last += sizeof(server_string) - 1;
}
if (!(r->headers_out.date && r->headers_out.date->key.len)) {
ngx_memcpy(h->last, "Date: ", 6);
h->last += 6;
h->last += ngx_http_get_time(h->last, time(NULL));
*(h->last++) = CR; *(h->last++) = LF;
}
/* 2^64 is 20 characters */
if (r->headers_out.content_length >= 0) {
h->last += ngx_snprintf(h->last, 49,
"Content-Length: " OFF_FMT CRLF,
r->headers_out.content_length);
}
#if 0
if (r->headers_out.content_type.len) {
ngx_memcpy(h->last, "Content-Type: ", 14);
h->last += 14;
ngx_memcpy(h->last, r->headers_out.content_type.data,
r->headers_out.content_type.len);
h->last += r->headers_out.content_type.len;
*(h->last++) = CR; *(h->last++) = LF;
}
#endif
if (!(r->headers_out.last_modified
&& r->headers_out.last_modified->key.len)
&& r->headers_out.last_modified_time != -1)
{
ngx_memcpy(h->last, "Last-Modified: ", 15);
h->last += 15;
h->last += ngx_http_get_time(h->last,
r->headers_out.last_modified_time);
*(h->last++) = CR; *(h->last++) = LF;
}
if (r->keepalive == 0) {
ngx_memcpy(h->last, "Connection: close" CRLF, 19);
h->last += 19;
} else {
ngx_memcpy(h->last, "Connection: keep-alive" CRLF, 24);
h->last += 24;
}
for (i = 0; i < r->headers_out.headers->nelts; i++) {
if (header[i].key.len == 0) {
continue;
}
ngx_memcpy(h->last, header[i].key.data, header[i].key.len);
h->last += header[i].key.len;
*(h->last++) = ':' ; *(h->last++) = ' ' ;
ngx_memcpy(h->last, header[i].value.data, header[i].value.len);
h->last += header[i].value.len;
*(h->last++) = CR; *(h->last++) = LF;
}
/* STUB */
*(h->last) = '\0';
ngx_log_debug(r->connection->log, "%s\n" _ h->pos);
/**/
/* end of HTTP header */
*(h->last++) = CR; *(h->last++) = LF;
if (r->header_only) {
h->type |= NGX_HUNK_LAST;
}
ngx_test_null(ch, ngx_palloc(r->pool, sizeof(ngx_chain_t)), NGX_ERROR);
ch->hunk = h;
ch->next = NULL;
return ngx_http_write_filter(r, ch);
}
static void ngx_http_header_filter_init(ngx_pool_t *pool,
ngx_http_conf_filter_t *cf)
{
cf->output_header_filter = ngx_http_header_filter;
}
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