// reference: ngx_http_proxy_process_header
static ngx_int_t __decode_header(ngx_http_request_t *r)
{
ngx_http_fetch_ctx_t * ctx = ngx_http_fetch_get_module_ctx(r);
for (;;)
{
ngx_int_t rc = ngx_http_parse_header_line(r, &r->upstream->buffer, 1);
if (rc == NGX_OK)
{
// a header line has been parsed successfully
if (NGX_ERROR == __decode_header_line(r, ctx->headers_in_hash))
{
return NGX_ERROR;
}
continue;
}
if (rc == NGX_HTTP_PARSE_HEADER_DONE)
{
// a whole header has been parsed successfully
return __finish_decode(r);
}
if (rc == NGX_AGAIN)
{
return NGX_AGAIN;
}
// there was error while a header line parsing
return NGX_HTTP_UPSTREAM_INVALID_HEADER;
}
return NGX_ERROR;
}
static ngx_int_t
ngx_http_poller_process_header(ngx_http_request_t *r)
{
static ngx_str_t content_length = ngx_string("Content-Length");
ngx_http_poller_t *poller;
ngx_http_upstream_t *u;
ngx_int_t rc;
ngx_str_t name;
ngx_str_t value;
poller = ngx_http_get_module_ctx(r, ngx_http_poller_module);
if (poller == NULL) {
return NGX_ERROR;
}
u = r->upstream;
for ( ;; ) {
rc = ngx_http_parse_header_line(r, &r->upstream->buffer, 1);
if (rc == NGX_OK) {
name.len = r->header_name_end - r->header_name_start;
name.data = r->header_name_start;
value.len = r->header_end - r->header_start;
value.data = r->header_start;
if (name.len == content_length.len &&
ngx_strncasecmp(name.data, content_length.data, name.len) == 0) {
u->headers_in.content_length_n = ngx_atoof(value.data, value.len);
}
if (poller->handler.header != NULL) {
poller->handler.header(r, &name, &value);
}
continue;
}
if (rc == NGX_HTTP_PARSE_HEADER_DONE) {
return NGX_OK;
}
if (rc == NGX_AGAIN) {
return NGX_AGAIN;
}
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"upstream sent invalid header");
return NGX_HTTP_UPSTREAM_INVALID_HEADER;
}
}
static ngx_int_t
zupstream_upstream_process_header(ngx_http_request_t *r)
{
ngx_int_t rc;
ngx_table_elt_t *h;
ngx_http_upstream_header_t *hh;
ngx_http_upstream_main_conf_t *umcf;
umcf = ngx_http_get_module_main_conf(r, ngx_http_upstream_module);
for ( ;; )
{
rc = ngx_http_parse_header_line(r, &r->upstream->buffer, 1);
if (rc == NGX_OK)
{
h = ngx_list_push(&r->upstream->headers_in.headers);
if (h == NULL)
{
return NGX_ERROR;
}
h->hash = r->header_hash;
h->key.len = r->header_name_end - r->header_name_start;
h->value.len = r->header_end - r->header_start;
h->key.data = ngx_pnalloc(r->pool,
h->key.len + 1 + h->value.len + 1 + h->key.len);
if (h->key.data == NULL)
{
return NGX_ERROR;
}
h->value.data = h->key.data + h->key.len + 1;
h->lowcase_key = h->key.data + h->key.len + 1 + h->value.len + 1;
ngx_memcpy(h->key.data, r->header_name_start, h->key.len);
h->key.data[h->key.len] = '\0';
ngx_memcpy(h->value.data, r->header_start, h->value.len);
h->value.data[h->value.len] = '\0';
if (h->key.len == r->lowcase_index)
{
ngx_memcpy(h->lowcase_key, r->lowcase_header, h->key.len);
}
else
{
ngx_strlow(h->lowcase_key, h->key.data, h->key.len);
}
hh = ngx_hash_find(&umcf->headers_in_hash, h->hash,
h->lowcase_key, h->key.len);
if (hh && hh->handler(r, h, hh->offset) != NGX_OK)
{
return NGX_ERROR;
}
continue;
}
if (rc == NGX_HTTP_PARSE_HEADER_DONE)
{
if (r->upstream->headers_in.server == NULL)
{
h = ngx_list_push(&r->upstream->headers_in.headers);
if (h == NULL)
{
return NGX_ERROR;
}
h->hash = ngx_hash(ngx_hash(ngx_hash(ngx_hash(
ngx_hash('s', 'e'), 'r'), 'v'), 'e'), 'r');
ngx_str_set(&h->key, "Server");
ngx_str_null(&h->value);
h->lowcase_key = (u_char *) "server";
}
if (r->upstream->headers_in.date == NULL)
{
h = ngx_list_push(&r->upstream->headers_in.headers);
if (h == NULL)
{
return NGX_ERROR;
}
h->hash = ngx_hash(ngx_hash(ngx_hash('d', 'a'), 't'), 'e');
ngx_str_set(&h->key, "Date");
ngx_str_null(&h->value);
h->lowcase_key = (u_char *) "date";
}
return NGX_OK;
}
if (rc == NGX_AGAIN)
{
return NGX_AGAIN;
}
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"upstream sent invalid header");
return NGX_HTTP_UPSTREAM_INVALID_HEADER;
}
}
static ngx_int_t
process_header(ngx_http_request_t *r)
{
ngx_str_t *status_line;
ngx_int_t rc, status;
ngx_table_elt_t *h;
ngx_http_upstream_t *u;
ngx_http_upstream_header_t *hh;
ngx_http_upstream_main_conf_t *umcf;
ngx_http_core_loc_conf_t *clcf;
umcf = ngx_http_get_module_main_conf(r, ngx_http_upstream_module);
clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
for ( ;; ) {
rc = ngx_http_parse_header_line(r, &r->upstream->buffer, 1);
if (rc == NGX_OK) {
/* a header line has been parsed successfully */
h = ngx_list_push(&r->upstream->headers_in.headers);
if (h == NULL) {
return NGX_ERROR;
}
h->hash = r->header_hash;
h->key.len = r->header_name_end - r->header_name_start;
h->value.len = r->header_end - r->header_start;
h->key.data = ngx_pnalloc(r->pool,
h->key.len + 1 + h->value.len + 1
+ h->key.len);
if (h->key.data == NULL) {
return NGX_ERROR;
}
h->value.data = h->key.data + h->key.len + 1;
h->lowcase_key = h->key.data + h->key.len + 1 + h->value.len + 1;
ngx_memcpy(h->key.data, r->header_name_start, h->key.len);
h->key.data[h->key.len] = '\0';
ngx_memcpy(h->value.data, r->header_start, h->value.len);
h->value.data[h->value.len] = '\0';
if (h->key.len == r->lowcase_index) {
ngx_memcpy(h->lowcase_key, r->lowcase_header, h->key.len);
} else {
ngx_strlow(h->lowcase_key, h->key.data, h->key.len);
}
hh = ngx_hash_find(&umcf->headers_in_hash, h->hash,
h->lowcase_key, h->key.len);
if (hh && hh->handler(r, h, hh->offset) != NGX_OK) {
return NGX_ERROR;
}
ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"http scgi header: \"%V: %V\"", &h->key, &h->value);
continue;
}
if (rc == NGX_HTTP_PARSE_HEADER_DONE) {
/* a whole header has been parsed successfully */
ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"http scgi header done");
/*
* if no "Server" and "Date" in header line,
* then add the default headers
*/
if (r->upstream->headers_in.server == NULL) {
h = ngx_list_push(&r->upstream->headers_in.headers);
if (h == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
h->hash = ngx_hash(ngx_hash(ngx_hash(ngx_hash(
ngx_hash('s', 'e'), 'r'), 'v'), 'e'), 'r');
h->key.len = sizeof("Server") - 1;
h->key.data = (u_char *) "Server";
if (!passenger_main_conf.show_version_in_header) {
if (clcf->server_tokens) {
h->value.data = (u_char *) (NGINX_VER " + " PROGRAM_NAME);
} else {
h->value.data = (u_char *) ("nginx + " PROGRAM_NAME);
}
} else {
if (clcf->server_tokens) {
h->value.data = (u_char *) (NGINX_VER " + " PROGRAM_NAME " " PASSENGER_VERSION);
} else {
h->value.data = (u_char *) ("nginx + " PROGRAM_NAME " " PASSENGER_VERSION);
}
}
h->value.len = ngx_strlen(h->value.data);
h->lowcase_key = (u_char *) "server";
}
if (r->upstream->headers_in.date == NULL) {
h = ngx_list_push(&r->upstream->headers_in.headers);
if (h == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
h->hash = ngx_hash(ngx_hash(ngx_hash('d', 'a'), 't'), 'e');
h->key.len = sizeof("Date") - 1;
h->key.data = (u_char *) "Date";
h->value.len = 0;
h->value.data = NULL;
h->lowcase_key = (u_char *) "date";
}
/* Process "Status" header. */
u = r->upstream;
if (u->headers_in.status_n) {
goto done;
}
if (u->headers_in.status) {
status_line = &u->headers_in.status->value;
status = ngx_atoi(status_line->data, 3);
if (status == NGX_ERROR) {
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"upstream sent invalid status \"%V\"",
status_line);
return NGX_HTTP_UPSTREAM_INVALID_HEADER;
}
u->headers_in.status_n = status;
u->headers_in.status_line = *status_line;
} else if (u->headers_in.location) {
u->headers_in.status_n = 302;
ngx_str_set(&u->headers_in.status_line,
"302 Moved Temporarily");
} else {
u->headers_in.status_n = 200;
ngx_str_set(&u->headers_in.status_line, "200 OK");
}
if (u->state && u->state->status == 0) {
u->state->status = u->headers_in.status_n;
}
done:
/* Supported since Nginx 1.3.15. */
#ifdef NGX_HTTP_SWITCHING_PROTOCOLS
if (u->headers_in.status_n == NGX_HTTP_SWITCHING_PROTOCOLS
&& r->headers_in.upgrade)
{
u->upgrade = 1;
}
#endif
return NGX_OK;
}
if (rc == NGX_AGAIN) {
return NGX_AGAIN;
}
/* there was error while a header line parsing */
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"upstream sent invalid header");
return NGX_HTTP_UPSTREAM_INVALID_HEADER;
}
}
ngx_int_t
ngx_http_srcache_process_header(ngx_http_request_t *r, ngx_buf_t *b)
{
ngx_int_t rc;
ngx_table_elt_t header;
ngx_http_srcache_ctx_t *ctx;
off_t len, rest;
unsigned truncate;
u_char *p;
ngx_http_srcache_header_t *hh;
ngx_http_srcache_main_conf_t *smcf;
smcf = ngx_http_get_module_main_conf(r, ngx_http_srcache_filter_module);
ctx = ngx_http_get_module_ctx(r, ngx_http_srcache_filter_module);
for ( ;; ) {
len = b->last - b->pos;
rest = ctx->header_buf->end - ctx->header_buf->last;
dd("len: %d, rest: %d", (int) len, (int) rest);
if (len > rest) {
len = rest;
truncate = 1;
} else {
truncate = 0;
}
ctx->header_buf->last = ngx_copy(ctx->header_buf->last, b->pos,
(size_t) len);
p = ctx->header_buf->pos;
rc = ngx_http_parse_header_line(r, ctx->header_buf, 1);
b->pos += ctx->header_buf->pos - p;
if (rc == NGX_OK) {
/* a header line has been parsed successfully */
ngx_memzero(&header, sizeof(ngx_table_elt_t));
header.hash = r->header_hash;
header.key.len = r->header_name_end - r->header_name_start;
header.value.len = r->header_end - r->header_start;
header.key.data = ngx_pnalloc(r->pool,
header.key.len + 1
+ header.value.len + 1
+ header.key.len);
if (header.key.data == NULL) {
return NGX_ERROR;
}
header.value.data = header.key.data + header.key.len + 1;
header.lowcase_key = header.key.data + header.key.len + 1
+ header.value.len + 1;
ngx_cpystrn(header.key.data, r->header_name_start,
header.key.len + 1);
ngx_cpystrn(header.value.data, r->header_start,
header.value.len + 1);
if (header.key.len == r->lowcase_index) {
ngx_memcpy(header.lowcase_key, r->lowcase_header,
header.key.len);
} else {
ngx_strlow(header.lowcase_key, header.key.data, header.key.len);
}
hh = ngx_hash_find(&smcf->headers_in_hash, header.hash,
header.lowcase_key, header.key.len);
if (hh) {
if (hh->handler(r->parent, &header, hh->offset) != NGX_OK) {
return NGX_ERROR;
}
} else {
if (ngx_http_srcache_process_header_line(r->parent, &header, 0)
!= NGX_OK)
{
return NGX_ERROR;
}
}
ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"srcache_fetch header: \"%V: %V\"",
&header.key, &header.value);
ctx->header_buf->pos = ctx->header_buf->start;
ctx->header_buf->last = ctx->header_buf->start;
continue;
}
if (rc == NGX_HTTP_PARSE_HEADER_DONE) {
/* a whole header has been parsed successfully */
ctx->header_buf->pos = ctx->header_buf->start;
ctx->header_buf->last = ctx->header_buf->start;
ngx_pfree(r->pool, ctx->header_buf->start);
ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"srcache_fetch header done");
return NGX_OK;
}
if (rc == NGX_AGAIN) {
if (truncate) {
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"srcache_fetch: header buffer overflown "
"(maybe you should consider increasing "
"srcache_header_buffer_size?)");
ctx->header_buf->pos = ctx->header_buf->start;
ctx->header_buf->last = ctx->header_buf->start;
ngx_pfree(r->pool, ctx->header_buf->start);
return NGX_ERROR;
}
return NGX_AGAIN;
}
/* there was error while a header line parsing */
ctx->header_buf->pos = ctx->header_buf->start;
ctx->header_buf->last = ctx->header_buf->start;
ngx_pfree(r->pool, ctx->header_buf->start);
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"srcache_fetch: cache sent invalid header");
return NGX_ERROR;
}
}
static ngx_int_t
process_header(ngx_http_request_t *r)
{
ngx_int_t rc;
ngx_uint_t i;
ngx_table_elt_t *h;
ngx_http_upstream_header_t *hh;
ngx_http_upstream_main_conf_t *umcf;
umcf = ngx_http_get_module_main_conf(r, ngx_http_upstream_module);
for ( ;; ) {
#if NGINX_VERSION_NUM >= 7000
rc = ngx_http_parse_header_line(r, &r->upstream->buffer, 1);
#else
rc = ngx_http_parse_header_line(r, &r->upstream->buffer);
#endif
if (rc == NGX_OK) {
/* a header line has been parsed successfully */
h = ngx_list_push(&r->upstream->headers_in.headers);
if (h == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
h->hash = r->header_hash;
h->key.len = r->header_name_end - r->header_name_start;
h->value.len = r->header_end - r->header_start;
h->key.data = ngx_palloc(r->pool,
h->key.len + 1 + h->value.len + 1 + h->key.len);
if (h->key.data == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
h->value.data = h->key.data + h->key.len + 1;
h->lowcase_key = h->key.data + h->key.len + 1 + h->value.len + 1;
ngx_cpystrn(h->key.data, r->header_name_start, h->key.len + 1);
ngx_cpystrn(h->value.data, r->header_start, h->value.len + 1);
if (h->key.len == r->lowcase_index) {
ngx_memcpy(h->lowcase_key, r->lowcase_header, h->key.len);
} else {
for (i = 0; i < h->key.len; i++) {
h->lowcase_key[i] = ngx_tolower(h->key.data[i]);
}
}
hh = ngx_hash_find(&umcf->headers_in_hash, h->hash,
h->lowcase_key, h->key.len);
if (hh && hh->handler(r, h, hh->offset) != NGX_OK) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"http scgi header: \"%V: %V\"",
&h->key, &h->value);
continue;
}
if (rc == NGX_HTTP_PARSE_HEADER_DONE) {
/* a whole header has been parsed successfully */
ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"http scgi header done");
/*
* if no "Server" and "Date" in header line,
* then add the default headers
*/
if (r->upstream->headers_in.server == NULL) {
h = ngx_list_push(&r->upstream->headers_in.headers);
if (h == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
h->hash = ngx_hash(ngx_hash(ngx_hash(ngx_hash(
ngx_hash('s', 'e'), 'r'), 'v'), 'e'), 'r');
h->key.len = sizeof("Server") - 1;
h->key.data = (u_char *) "Server";
h->value.data = (u_char *) (NGINX_VER " + Phusion Passenger " PASSENGER_VERSION " (mod_rails/mod_rack)");
h->value.len = ngx_strlen(h->value.data);
h->lowcase_key = (u_char *) "server";
}
if (r->upstream->headers_in.date == NULL) {
h = ngx_list_push(&r->upstream->headers_in.headers);
if (h == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
h->hash = ngx_hash(ngx_hash(ngx_hash('d', 'a'), 't'), 'e');
h->key.len = sizeof("Date") - 1;
h->key.data = (u_char *) "Date";
h->value.len = 0;
h->value.data = NULL;
h->lowcase_key = (u_char *) "date";
}
return NGX_OK;
}
if (rc == NGX_AGAIN) {
return NGX_AGAIN;
}
/* there was error while a header line parsing */
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"upstream sent invalid header");
return NGX_HTTP_UPSTREAM_INVALID_HEADER;
}
}
//mytest_upstream_process_header方法可以解析HTTP响应头部，而这里只是简单的
//把上游服务器发送的HTTP头部添加到了请求r->upstream->headers_in.headers链表
//中。
static ngx_int_t
mytest_upstream_process_header(ngx_http_request_t *r)
{
ngx_int_t rc;
ngx_table_elt_t *h;
ngx_http_upstream_header_t *hh;
ngx_http_upstream_main_conf_t *umcf;
//这里将upstream模块配置项ngx_http_upstream_main_conf_t取出来，对将要转发给
//下游客户端的HTTP响应头部进行统一处理
umcf = ngx_http_get_module_main_conf(r, ngx_http_upstream_module);
//循环的解析所有的HTTP头部
for(;;){
//HTTP框架提供了基础性的ngx_http_parse_header_line方法，它用于解析HTTP头部
rc = ngx_http_parse_header_line(r, &r->upstream->buffer, 1);
//返回NGX_OK时，表示解析出一行HTTP头部
if(rc == NGX_OK){
//向headers_in.headers这个ngx_list_t链表中添加HTTP头部
h = ngx_list_push(&r->upstream->headers_in.headers);
if(h == NULL){
return NGX_ERROR;
}
//下面开始构造刚刚添加到headers链表中的HTTP头部
h->hash = r->header_hash;
h->key.len = r->header_name_end - r->header_name_start;
h->value.len = r->header_end - r->header_start;
//必须在内存池中非配存放HTTP头部的内存空间
h->key.data = ngx_pnalloc(r->pool,
h->key.len + 1 + h->value.len + 1 + h->key.len);
if(h->key.data == NULL){
return NGX_ERROR;
}
h->value.data = h->key.data + h->key.len + 1;
h->lowcase_key = h->key.data + h->key.len + 1 + h->value.len + 1;
ngx_memcpy(h->key.data, r->header_name_start, h->key.len);
h->value.data[h->value.len] = '\0';
ngx_memcpy(h->value.data, r->header_start, h->value.len);
h->value.data[h->value.len] = '\0';
if(h->key.len == r->lowcase_index){
ngx_memcpy(h->lowcase_key, r->lowcase_header, h->key.len);
} else {
ngx_strlow(h->lowcase_key, h->key.data, h->key.len);
}
//upstream模块会对一些HTTP头部作特殊处理
hh = ngx_hash_find(&umcf->headers_in_hash, h->hash, h->lowcase_key, h->key.len);
if(hh && hh->handler(r, h, hh->offset) != NGX_OK){
return NGX_ERROR;
}
continue;
}
//返回NGX_HTTP_PARSE_HEADER_DONE时，表示响应中的所有的HTTP头部都解析完毕，接下来
//在接收到的都将是HTTP包体
if(rc == NGX_HTTP_PARSE_HEADER_DONE) {
//如果之前解析HTTP头部时没有发现server和date头部，那么下面会根据HTTP协议
//规范添加这两个头部
if(r->upstream->headers_in.server == NULL){
h = ngx_list_push(&r->upstream->headers_in.headers);
if(h == NULL){
return NGX_ERROR;
}
h->hash = ngx_hash(ngx_hash(ngx_hash(ngx_hash(ngx_hash('s', 'e'),
'r'), 'v'), 'e'), 'r');
ngx_str_set(&h->key, "Server");
ngx_str_null(&h->value);
h->lowcase_key = (u_char *)"server";
}
if(r->upstream->headers_in.date == NULL){
h = ngx_list_push(&r->upstream->headers_in.headers);
if(h == NULL){
return NGX_ERROR;
}
h->hash = ngx_hash(ngx_hash(ngx_hash('d', 'a'), 't'), 'e');
ngx_str_set(&h->key, "Date");
ngx_str_null(&h->value);
h->lowcase_key = (u_char *)"date";
}
return NGX_OK;
}
//如果返回NGX_AGAIN,则表示状态机还没有解析到完整的HTTP头部，此时要求upstream模块
//继续接收新的字符流，然后交由process_header回调方法解析
if(rc == NGX_AGAIN){
return NGX_AGAIN;
}
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"upstream sent invalid header");
return NGX_HTTP_UPSTREAM_INVALID_HEADER; //当mytest_upstream_process_header返回NGX_OK后
//upstream模块开始把上游的包体直接转发到下游客户端
}
}
static ngx_int_t
ngx_http_scgi_process_header(ngx_http_request_t *r)
{
ngx_str_t *status_line;
ngx_int_t rc, status;
ngx_table_elt_t *h;
ngx_http_upstream_t *u;
ngx_http_upstream_header_t *hh;
ngx_http_upstream_main_conf_t *umcf;
umcf = ngx_http_get_module_main_conf(r, ngx_http_upstream_module);
for ( ;; ) {
rc = ngx_http_parse_header_line(r, &r->upstream->buffer, 1);
if (rc == NGX_OK) {
/* a header line has been parsed successfully */
h = ngx_list_push(&r->upstream->headers_in.headers);
if (h == NULL) {
return NGX_ERROR;
}
h->hash = r->header_hash;
h->key.len = r->header_name_end - r->header_name_start;
h->value.len = r->header_end - r->header_start;
h->key.data = ngx_pnalloc(r->pool,
h->key.len + 1 + h->value.len + 1
+ h->key.len);
if (h->key.data == NULL) {
return NGX_ERROR;
}
h->value.data = h->key.data + h->key.len + 1;
h->lowcase_key = h->key.data + h->key.len + 1 + h->value.len + 1;
ngx_cpystrn(h->key.data, r->header_name_start, h->key.len + 1);
ngx_cpystrn(h->value.data, r->header_start, h->value.len + 1);
if (h->key.len == r->lowcase_index) {
ngx_memcpy(h->lowcase_key, r->lowcase_header, h->key.len);
} else {
ngx_strlow(h->lowcase_key, h->key.data, h->key.len);
}
hh = ngx_hash_find(&umcf->headers_in_hash, h->hash,
h->lowcase_key, h->key.len);
if (hh && hh->handler(r, h, hh->offset) != NGX_OK) {
return NGX_ERROR;
}
ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"http scgi header: \"%V: %V\"", &h->key, &h->value);
continue;
}
if (rc == NGX_HTTP_PARSE_HEADER_DONE) {
/* a whole header has been parsed successfully */
ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"http scgi header done");
if (r->http_version > NGX_HTTP_VERSION_9) {
return NGX_OK;
}
u = r->upstream;
if (u->headers_in.status) {
status_line = &u->headers_in.status->value;
status = ngx_atoi(status_line->data, 3);
if (status == NGX_ERROR) {
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"upstream sent invalid status \"%V\"",
status_line);
return NGX_HTTP_UPSTREAM_INVALID_HEADER;
}
r->http_version = NGX_HTTP_VERSION_10;
u->headers_in.status_n = status;
u->headers_in.status_line = *status_line;
} else if (u->headers_in.location) {
r->http_version = NGX_HTTP_VERSION_10;
u->headers_in.status_n = 302;
ngx_str_set(&u->headers_in.status_line,
"302 Moved Temporarily");
} else {
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"upstream sent neither valid HTTP/1.0 header "
"nor \"Status\" header line");
u->headers_in.status_n = 200;
ngx_str_set(&u->headers_in.status_line, "200 OK");
}
if (u->state) {
u->state->status = u->headers_in.status_n;
}
return NGX_OK;
}
if (rc == NGX_AGAIN) {
return NGX_AGAIN;
}
/* there was error while a header line parsing */
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"upstream sent invalid header");
return NGX_HTTP_UPSTREAM_INVALID_HEADER;
}
}
static ngx_int_t
mytest_upstream_process_header(ngx_http_request_t *r)
{
ngx_int_t rc;
ngx_table_elt_t *h;
ngx_http_upstream_header_t *hh;
ngx_http_upstream_main_conf_t *umcf;
//这里将upstream模块配置项ngx_http_upstream_main_conf_t取了
//出来，目的只有1个，对将要转发给下游客户端的http响应头部作统一
//处理。该结构体中存储了需要做统一处理的http头部名称和回调方法
umcf = ngx_http_get_module_main_conf(r, ngx_http_upstream_module);
//循环的解析所有的http头部
for ( ;; )
{
// http框架提供了基础性的ngx_http_parse_header_line
//方法，它用于解析http头部
rc = ngx_http_parse_header_line(r, &r->upstream->buffer, 1);
//返回NGX_OK表示解析出一行http头部
if (rc == NGX_OK)
{
//向headers_in.headers这个ngx_list_t链表中添加http头部
h = ngx_list_push(&r->upstream->headers_in.headers);
if (h == NULL)
{
return NGX_ERROR;
}
//以下开始构造刚刚添加到headers链表中的http头部
h->hash = r->header_hash;
h->key.len = r->header_name_end - r->header_name_start;
h->value.len = r->header_end - r->header_start;
//必须由内存池中分配存放http头部的内存
h->key.data = ngx_pnalloc(r->pool,
h->key.len + 1 + h->value.len + 1 + h->key.len);
if (h->key.data == NULL)
{
return NGX_ERROR;
}
h->value.data = h->key.data + h->key.len + 1;
h->lowcase_key = h->key.data + h->key.len + 1 + h->value.len + 1;
ngx_memcpy(h->key.data, r->header_name_start, h->key.len);
h->key.data[h->key.len] = '\0';
ngx_memcpy(h->value.data, r->header_start, h->value.len);
h->value.data[h->value.len] = '\0';
if (h->key.len == r->lowcase_index)
{
ngx_memcpy(h->lowcase_key, r->lowcase_header, h->key.len);
}
else
{
ngx_strlow(h->lowcase_key, h->key.data, h->key.len);
}
//upstream模块会对一些http头部做特殊处理
hh = ngx_hash_find(&umcf->headers_in_hash, h->hash,
h->lowcase_key, h->key.len);
if (hh && hh->handler(r, h, hh->offset) != NGX_OK)
{
return NGX_ERROR;
}
continue;
}
//返回NGX_HTTP_PARSE_HEADER_DONE表示响应中所有的http头部都解析
//完毕，接下来再接收到的都将是http包体
if (rc == NGX_HTTP_PARSE_HEADER_DONE)
{
//如果之前解析http头部时没有发现server和date头部，以下会
//根据http协议添加这两个头部
if (r->upstream->headers_in.server == NULL)
{
h = ngx_list_push(&r->upstream->headers_in.headers);
if (h == NULL)
{
return NGX_ERROR;
}
h->hash = ngx_hash(ngx_hash(ngx_hash(ngx_hash(
ngx_hash('s', 'e'), 'r'), 'v'), 'e'), 'r');
ngx_str_set(&h->key, "Server");
ngx_str_null(&h->value);
h->lowcase_key = (u_char *) "server";
}
if (r->upstream->headers_in.date == NULL)
{
h = ngx_list_push(&r->upstream->headers_in.headers);
if (h == NULL)
{
return NGX_ERROR;
}
h->hash = ngx_hash(ngx_hash(ngx_hash('d', 'a'), 't'), 'e');
ngx_str_set(&h->key, "Date");
ngx_str_null(&h->value);
h->lowcase_key = (u_char *) "date";
}
return NGX_OK;
}
//如果返回NGX_AGAIN则表示状态机还没有解析到完整的http头部，
//要求upstream模块继续接收新的字符流再交由process_header
//回调方法解析
if (rc == NGX_AGAIN)
{
return NGX_AGAIN;
}
//其他返回值都是非法的
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"upstream sent invalid header");
return NGX_HTTP_UPSTREAM_INVALID_HEADER;
}
}
