curl/lib/dynhds.c
Stefan Eissing 61f52a97e9
lib: add bufq and dynhds
Adding `bufq`:
- at init() time configured to hold up to `n` chunks of `m` bytes each.
- various methods for reading from and writing to it.
- `peek` support to get access to buffered data without copy
- `pass` support to allow buffer flushing on write if it becomes full
- use case: IO buffers for dynamic reads and writes that do not blow up
- distinct from `dynbuf` in that:
  - it maintains a read position
  - writes on a full bufq return CURLE_AGAIN instead of nuking itself
- Init options:
  - SOFT_LIMIT: allow writes into a full bufq
  - NO_SPARES: free empty chunks right away
- a `bufc_pool` that can keep a number of spare chunks to
  be shared between different `bufq` instances

Adding `dynhds`:
- a straightforward list of name+value pairs as used for HTTP headers
- headers can be appended dynamically
- headers can be removed again
- headers can be replaced
- headers can be looked up
- http/1.1 formatting into a `dynbuf`
- configured at init() with limits on header counts and total string
  sizes
- use case: pass a HTTP request or response around without being version
  specific
- express a HTTP request without a curl easy handle (used in h2 proxy
  tunnels)
- future extension possibilities:
  - conversions of `dynhds` to nghttp2/nghttp3 name+value arrays

Closes #10720
2023-03-30 09:08:05 +02:00

304 lines
8.0 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
#include "curl_setup.h"
#include "dynhds.h"
#include "strcase.h"
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"
static struct dynhds_entry *
entry_new(const char *name, size_t namelen,
const char *value, size_t valuelen)
{
struct dynhds_entry *e;
char *p;
DEBUGASSERT(name);
DEBUGASSERT(value);
e = calloc(1, sizeof(*e) + namelen + valuelen + 2);
if(!e)
return NULL;
e->name = p = ((char *)e) + sizeof(*e);
memcpy(p, name, namelen);
e->namelen = namelen;
e->value = p += namelen + 1; /* leave a \0 at the end of name */
memcpy(p, value, valuelen);
e->valuelen = valuelen;
return e;
}
static void entry_free(struct dynhds_entry *e)
{
free(e);
}
void Curl_dynhds_init(struct dynhds *dynhds, size_t max_entries,
size_t max_strs_size)
{
DEBUGASSERT(dynhds);
DEBUGASSERT(max_strs_size);
dynhds->hds = NULL;
dynhds->hds_len = dynhds->hds_allc = dynhds->strs_len = 0;
dynhds->max_entries = max_entries;
dynhds->max_strs_size = max_strs_size;
}
void Curl_dynhds_free(struct dynhds *dynhds)
{
DEBUGASSERT(dynhds);
if(dynhds->hds && dynhds->hds_len) {
size_t i;
DEBUGASSERT(dynhds->hds);
for(i = 0; i < dynhds->hds_len; ++i) {
entry_free(dynhds->hds[i]);
}
}
Curl_safefree(dynhds->hds);
dynhds->hds_len = dynhds->hds_allc = dynhds->strs_len = 0;
}
void Curl_dynhds_reset(struct dynhds *dynhds)
{
DEBUGASSERT(dynhds);
if(dynhds->hds_len) {
size_t i;
DEBUGASSERT(dynhds->hds);
for(i = 0; i < dynhds->hds_len; ++i) {
entry_free(dynhds->hds[i]);
dynhds->hds[i] = NULL;
}
}
dynhds->hds_len = dynhds->strs_len = 0;
}
size_t Curl_dynhds_count(struct dynhds *dynhds)
{
return dynhds->hds_len;
}
struct dynhds_entry *Curl_dynhds_getn(struct dynhds *dynhds, size_t n)
{
DEBUGASSERT(dynhds);
return (n < dynhds->hds_len)? dynhds->hds[n] : NULL;
}
struct dynhds_entry *Curl_dynhds_get(struct dynhds *dynhds, const char *name,
size_t namelen)
{
size_t i;
for(i = 0; i < dynhds->hds_len; ++i) {
if(dynhds->hds[i]->namelen == namelen &&
strncasecompare(dynhds->hds[i]->name, name, namelen)) {
return dynhds->hds[i];
}
}
return NULL;
}
struct dynhds_entry *Curl_dynhds_cget(struct dynhds *dynhds, const char *name)
{
return Curl_dynhds_get(dynhds, name, strlen(name));
}
bool Curl_dynhds_contains(struct dynhds *dynhds,
const char *name, size_t namelen)
{
return !!Curl_dynhds_get(dynhds, name, namelen);
}
bool Curl_dynhds_ccontains(struct dynhds *dynhds, const char *name)
{
return Curl_dynhds_contains(dynhds, name, strlen(name));
}
CURLcode Curl_dynhds_add(struct dynhds *dynhds,
const char *name, size_t namelen,
const char *value, size_t valuelen)
{
struct dynhds_entry *entry = NULL;
CURLcode result = CURLE_OUT_OF_MEMORY;
DEBUGASSERT(dynhds);
if(dynhds->max_entries && dynhds->hds_len >= dynhds->max_entries)
return CURLE_OUT_OF_MEMORY;
if(dynhds->strs_len + namelen + valuelen > dynhds->max_strs_size)
return CURLE_OUT_OF_MEMORY;
entry = entry_new(name, namelen, value, valuelen);
if(!entry)
goto out;
if(dynhds->hds_len + 1 >= dynhds->hds_allc) {
size_t nallc = dynhds->hds_len + 16;
struct dynhds_entry **nhds;
if(dynhds->max_entries && nallc > dynhds->max_entries)
nallc = dynhds->max_entries;
nhds = calloc(nallc, sizeof(struct dynhds_entry *));
if(!nhds)
goto out;
if(dynhds->hds) {
memcpy(nhds, dynhds->hds,
dynhds->hds_len * sizeof(struct dynhds_entry *));
Curl_safefree(dynhds->hds);
}
dynhds->hds = nhds;
dynhds->hds_allc = nallc;
}
dynhds->hds[dynhds->hds_len++] = entry;
entry = NULL;
dynhds->strs_len += namelen + valuelen;
result = CURLE_OK;
out:
if(entry)
entry_free(entry);
return result;
}
CURLcode Curl_dynhds_cadd(struct dynhds *dynhds,
const char *name, const char *value)
{
return Curl_dynhds_add(dynhds, name, strlen(name), value, strlen(value));
}
CURLcode Curl_dynhds_set(struct dynhds *dynhds,
const char *name, size_t namelen,
const char *value, size_t valuelen)
{
Curl_dynhds_remove(dynhds, name, namelen);
return Curl_dynhds_add(dynhds, name, namelen, value, valuelen);
}
CURLcode Curl_dynhds_cset(struct dynhds *dynhds,
const char *name, const char *value)
{
return Curl_dynhds_set(dynhds, name, strlen(name), value, strlen(value));
}
CURLcode Curl_dynhds_h1_cadd_line(struct dynhds *dynhds, const char *line)
{
const char *p;
const char *name;
size_t namelen;
const char *value;
size_t valuelen;
if(!line)
return CURLE_OK;
p = strchr(line, ':');
if(!p) {
return CURLE_BAD_FUNCTION_ARGUMENT;
}
name = line;
namelen = p - line;
p++; /* move past the colon */
while(ISBLANK(*p))
p++;
value = p;
p = strchr(value, '\r');
if(!p)
p = strchr(value, '\n');
valuelen = p? ((size_t)(p - value)) : strlen(value);
return Curl_dynhds_add(dynhds, name, namelen, value, valuelen);
}
size_t Curl_dynhds_count_name(struct dynhds *dynhds,
const char *name, size_t namelen)
{
size_t n = 0;
if(dynhds->hds_len) {
size_t i;
for(i = 0; i < dynhds->hds_len; ++i) {
if((namelen == dynhds->hds[i]->namelen) &&
strncasecompare(name, dynhds->hds[i]->name, namelen))
++n;
}
}
return n;
}
size_t Curl_dynhds_ccount_name(struct dynhds *dynhds, const char *name)
{
return Curl_dynhds_count_name(dynhds, name, strlen(name));
}
size_t Curl_dynhds_remove(struct dynhds *dynhds,
const char *name, size_t namelen)
{
size_t n = 0;
if(dynhds->hds_len) {
size_t i, len;
for(i = 0; i < dynhds->hds_len; ++i) {
if((namelen == dynhds->hds[i]->namelen) &&
strncasecompare(name, dynhds->hds[i]->name, namelen)) {
++n;
--dynhds->hds_len;
dynhds->strs_len -= (dynhds->hds[i]->namelen +
dynhds->hds[i]->valuelen);
entry_free(dynhds->hds[i]);
len = dynhds->hds_len - i; /* remaining entries */
if(len) {
memmove(&dynhds->hds[i], &dynhds->hds[i + 1],
len * sizeof(dynhds->hds[i]));
}
--i; /* do this index again */
}
}
}
return n;
}
size_t Curl_dynhds_cremove(struct dynhds *dynhds, const char *name)
{
return Curl_dynhds_remove(dynhds, name, strlen(name));
}
CURLcode Curl_dynhds_h1_dprint(struct dynhds *dynhds, struct dynbuf *dbuf)
{
CURLcode result = CURLE_OK;
size_t i;
if(!dynhds->hds_len)
return result;
for(i = 0; i < dynhds->hds_len; ++i) {
result = Curl_dyn_addf(dbuf, "%.*s: %.*s\r\n",
(int)dynhds->hds[i]->namelen, dynhds->hds[i]->name,
(int)dynhds->hds[i]->valuelen, dynhds->hds[i]->value);
if(result)
break;
}
return result;
}