From 34cf40321c3cfa5160e34a87a816b7c6030c0296 Mon Sep 17 00:00:00 2001 From: Patrick Monnerat Date: Tue, 23 Mar 2021 02:02:18 +0100 Subject: bufref: buffer reference support A struct bufref holds a buffer pointer, a data size and a destructor. When freed or its contents are changed, the previous buffer is implicitly released by the associated destructor. The data size, although not used internally, allows binary data support. A unit test checks its handling methods: test 1661 Closes #6654 --- lib/Makefile.inc | 2 + lib/bufref.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ lib/bufref.h | 46 ++++++++++++++++++++ 3 files changed, 175 insertions(+) create mode 100644 lib/bufref.c create mode 100644 lib/bufref.h (limited to 'lib') diff --git a/lib/Makefile.inc b/lib/Makefile.inc index 90ec6aa05..3e9ddec12 100644 --- a/lib/Makefile.inc +++ b/lib/Makefile.inc @@ -97,6 +97,7 @@ LIB_CFILES = \ asyn-ares.c \ asyn-thread.c \ base64.c \ + bufref.c \ c-hyper.c \ conncache.c \ connect.c \ @@ -217,6 +218,7 @@ LIB_HFILES = \ amigaos.h \ arpa_telnet.h \ asyn.h \ + bufref.h \ c-hyper.h \ conncache.h \ connect.h \ diff --git a/lib/bufref.c b/lib/bufref.c new file mode 100644 index 000000000..b84511e18 --- /dev/null +++ b/lib/bufref.c @@ -0,0 +1,127 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 2021, Daniel Stenberg, , 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. + * + ***************************************************************************/ + +#include "curl_setup.h" +#include "urldata.h" +#include "bufref.h" + +#include "curl_memory.h" +#include "memdebug.h" + +#define SIGNATURE 0x5c48e9b2 /* Random pattern. */ + +/* + * Init a bufref struct. + */ +void Curl_bufref_init(struct bufref *br) +{ + DEBUGASSERT(br); + br->dtor = NULL; + br->ptr = NULL; + br->len = 0; + +#ifdef DEBUGBUILD + br->signature = SIGNATURE; +#endif +} + +/* + * Free the buffer and re-init the necessary fields. It doesn't touch the + * 'signature' field and thus this buffer reference can be reused. + */ + +void Curl_bufref_free(struct bufref *br) +{ + DEBUGASSERT(br); + DEBUGASSERT(br->signature == SIGNATURE); + DEBUGASSERT(br->ptr || !br->len); + + if(br->ptr && br->dtor) + br->dtor((void *) br->ptr); + + br->dtor = NULL; + br->ptr = NULL; + br->len = 0; +} + +/* + * Set the buffer reference to new values. The previously referenced buffer + * is released before assignment. + */ +void Curl_bufref_set(struct bufref *br, const void *ptr, size_t len, + void (*dtor)(void *)) +{ + DEBUGASSERT(ptr || !len); + DEBUGASSERT(len <= CURL_MAX_INPUT_LENGTH); + + Curl_bufref_free(br); + br->ptr = (const unsigned char *) ptr; + br->len = len; + br->dtor = dtor; +} + +/* + * Get a pointer to the referenced buffer. + */ +const unsigned char *Curl_bufref_ptr(const struct bufref *br) +{ + DEBUGASSERT(br); + DEBUGASSERT(br->signature == SIGNATURE); + DEBUGASSERT(br->ptr || !br->len); + + return br->ptr; +} + +/* + * Get the length of the referenced buffer data. + */ +size_t Curl_bufref_len(const struct bufref *br) +{ + DEBUGASSERT(br); + DEBUGASSERT(br->signature == SIGNATURE); + DEBUGASSERT(br->ptr || !br->len); + + return br->len; +} + +CURLcode Curl_bufref_memdup(struct bufref *br, const void *ptr, size_t len) +{ + unsigned char *cpy = NULL; + + DEBUGASSERT(br); + DEBUGASSERT(br->signature == SIGNATURE); + DEBUGASSERT(br->ptr || !br->len); + DEBUGASSERT(ptr || !len); + DEBUGASSERT(len <= CURL_MAX_INPUT_LENGTH); + + if(ptr) { + cpy = malloc(len + 1); + if(!cpy) + return CURLE_OUT_OF_MEMORY; + if(len) + memcpy(cpy, ptr, len); + cpy[len] = '\0'; + } + + Curl_bufref_set(br, cpy, len, curl_free); + return CURLE_OK; +} diff --git a/lib/bufref.h b/lib/bufref.h new file mode 100644 index 000000000..25f65d894 --- /dev/null +++ b/lib/bufref.h @@ -0,0 +1,46 @@ +#ifndef HEADER_CURL_BUFREF_H +#define HEADER_CURL_BUFREF_H +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 2021, Daniel Stenberg, , 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. + * + ***************************************************************************/ + +/* + * Generic buffer reference. + */ +struct bufref { + void (*dtor)(void *); /* Associated destructor. */ + const unsigned char *ptr; /* Referenced data buffer. */ + size_t len; /* The data size in bytes. */ +#ifdef DEBUGBUILD + int signature; /* Detect API use mistakes. */ +#endif +}; + + +void Curl_bufref_init(struct bufref *br); +void Curl_bufref_set(struct bufref *br, const void *ptr, size_t len, + void (*dtor)(void *)); +const unsigned char *Curl_bufref_ptr(const struct bufref *br); +size_t Curl_bufref_len(const struct bufref *br); +CURLcode Curl_bufref_memdup(struct bufref *br, const void *ptr, size_t len); +void Curl_bufref_free(struct bufref *br); + +#endif -- cgit v1.2.1