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Diffstat (limited to '')
| -rw-r--r-- | talloc.c | 3070 |
1 files changed, 3070 insertions, 0 deletions
diff --git a/talloc.c b/talloc.c new file mode 100644 index 0000000..3a93a82 --- /dev/null +++ b/talloc.c @@ -0,0 +1,3070 @@ +/* + Samba Unix SMB/CIFS implementation. + + Samba trivial allocation library - new interface + + NOTE: Please read talloc_guide.txt for full documentation + + Copyright (C) Andrew Tridgell 2004 + Copyright (C) Stefan Metzmacher 2006 + + ** NOTE! The following LGPL license applies to the talloc + ** library. This does NOT imply that all of Samba is released + ** under the LGPL + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 3 of the License, or (at your option) any later version. + + This library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, see <http://www.gnu.org/licenses/>. +*/ + +/* + inspired by http://swapped.cc/halloc/ +*/ + +#include "replace.h" +#include "talloc.h" + +#ifdef HAVE_SYS_AUXV_H +#include <sys/auxv.h> +#endif + +#if (TALLOC_VERSION_MAJOR != TALLOC_BUILD_VERSION_MAJOR) +#error "TALLOC_VERSION_MAJOR != TALLOC_BUILD_VERSION_MAJOR" +#endif + +#if (TALLOC_VERSION_MINOR != TALLOC_BUILD_VERSION_MINOR) +#error "TALLOC_VERSION_MINOR != TALLOC_BUILD_VERSION_MINOR" +#endif + +/* Special macros that are no-ops except when run under Valgrind on + * x86. They've moved a little bit from valgrind 1.0.4 to 1.9.4 */ +#ifdef HAVE_VALGRIND_MEMCHECK_H + /* memcheck.h includes valgrind.h */ +#include <valgrind/memcheck.h> +#elif defined(HAVE_VALGRIND_H) +#include <valgrind.h> +#endif + +#define MAX_TALLOC_SIZE 0x10000000 + +#define TALLOC_FLAG_FREE 0x01 +#define TALLOC_FLAG_LOOP 0x02 +#define TALLOC_FLAG_POOL 0x04 /* This is a talloc pool */ +#define TALLOC_FLAG_POOLMEM 0x08 /* This is allocated in a pool */ + +/* + * Bits above this are random, used to make it harder to fake talloc + * headers during an attack. Try not to change this without good reason. + */ +#define TALLOC_FLAG_MASK 0x0F + +#define TALLOC_MAGIC_REFERENCE ((const char *)1) + +#define TALLOC_MAGIC_BASE 0xe814ec70 +#define TALLOC_MAGIC_NON_RANDOM ( \ + ~TALLOC_FLAG_MASK & ( \ + TALLOC_MAGIC_BASE + \ + (TALLOC_BUILD_VERSION_MAJOR << 24) + \ + (TALLOC_BUILD_VERSION_MINOR << 16) + \ + (TALLOC_BUILD_VERSION_RELEASE << 8))) +static unsigned int talloc_magic = TALLOC_MAGIC_NON_RANDOM; + +/* by default we abort when given a bad pointer (such as when talloc_free() is called + on a pointer that came from malloc() */ +#ifndef TALLOC_ABORT +#define TALLOC_ABORT(reason) abort() +#endif + +#ifndef discard_const_p +#if defined(__intptr_t_defined) || defined(HAVE_INTPTR_T) +# define discard_const_p(type, ptr) ((type *)((intptr_t)(ptr))) +#else +# define discard_const_p(type, ptr) ((type *)(ptr)) +#endif +#endif + +/* these macros gain us a few percent of speed on gcc */ +#if (__GNUC__ >= 3) +/* the strange !! is to ensure that __builtin_expect() takes either 0 or 1 + as its first argument */ +#ifndef likely +#define likely(x) __builtin_expect(!!(x), 1) +#endif +#ifndef unlikely +#define unlikely(x) __builtin_expect(!!(x), 0) +#endif +#else +#ifndef likely +#define likely(x) (x) +#endif +#ifndef unlikely +#define unlikely(x) (x) +#endif +#endif + +/* this null_context is only used if talloc_enable_leak_report() or + talloc_enable_leak_report_full() is called, otherwise it remains + NULL +*/ +static void *null_context; +static bool talloc_report_null; +static bool talloc_report_null_full; +static void *autofree_context; + +static void talloc_setup_atexit(void); + +/* used to enable fill of memory on free, which can be useful for + * catching use after free errors when valgrind is too slow + */ +static struct { + bool initialised; + bool enabled; + uint8_t fill_value; +} talloc_fill; + +#define TALLOC_FILL_ENV "TALLOC_FREE_FILL" + +/* + * do not wipe the header, to allow the + * double-free logic to still work + */ +#define TC_INVALIDATE_FULL_FILL_CHUNK(_tc) do { \ + if (unlikely(talloc_fill.enabled)) { \ + size_t _flen = (_tc)->size; \ + char *_fptr = (char *)TC_PTR_FROM_CHUNK(_tc); \ + memset(_fptr, talloc_fill.fill_value, _flen); \ + } \ +} while (0) + +#if defined(DEVELOPER) && defined(VALGRIND_MAKE_MEM_NOACCESS) +/* Mark the whole chunk as not accessible */ +#define TC_INVALIDATE_FULL_VALGRIND_CHUNK(_tc) do { \ + size_t _flen = TC_HDR_SIZE + (_tc)->size; \ + char *_fptr = (char *)(_tc); \ + VALGRIND_MAKE_MEM_NOACCESS(_fptr, _flen); \ +} while(0) +#else +#define TC_INVALIDATE_FULL_VALGRIND_CHUNK(_tc) do { } while (0) +#endif + +#define TC_INVALIDATE_FULL_CHUNK(_tc) do { \ + TC_INVALIDATE_FULL_FILL_CHUNK(_tc); \ + TC_INVALIDATE_FULL_VALGRIND_CHUNK(_tc); \ +} while (0) + +#define TC_INVALIDATE_SHRINK_FILL_CHUNK(_tc, _new_size) do { \ + if (unlikely(talloc_fill.enabled)) { \ + size_t _flen = (_tc)->size - (_new_size); \ + char *_fptr = (char *)TC_PTR_FROM_CHUNK(_tc); \ + _fptr += (_new_size); \ + memset(_fptr, talloc_fill.fill_value, _flen); \ + } \ +} while (0) + +#if defined(DEVELOPER) && defined(VALGRIND_MAKE_MEM_NOACCESS) +/* Mark the unused bytes not accessible */ +#define TC_INVALIDATE_SHRINK_VALGRIND_CHUNK(_tc, _new_size) do { \ + size_t _flen = (_tc)->size - (_new_size); \ + char *_fptr = (char *)TC_PTR_FROM_CHUNK(_tc); \ + _fptr += (_new_size); \ + VALGRIND_MAKE_MEM_NOACCESS(_fptr, _flen); \ +} while (0) +#else +#define TC_INVALIDATE_SHRINK_VALGRIND_CHUNK(_tc, _new_size) do { } while (0) +#endif + +#define TC_INVALIDATE_SHRINK_CHUNK(_tc, _new_size) do { \ + TC_INVALIDATE_SHRINK_FILL_CHUNK(_tc, _new_size); \ + TC_INVALIDATE_SHRINK_VALGRIND_CHUNK(_tc, _new_size); \ +} while (0) + +#define TC_UNDEFINE_SHRINK_FILL_CHUNK(_tc, _new_size) do { \ + if (unlikely(talloc_fill.enabled)) { \ + size_t _flen = (_tc)->size - (_new_size); \ + char *_fptr = (char *)TC_PTR_FROM_CHUNK(_tc); \ + _fptr += (_new_size); \ + memset(_fptr, talloc_fill.fill_value, _flen); \ + } \ +} while (0) + +#if defined(DEVELOPER) && defined(VALGRIND_MAKE_MEM_UNDEFINED) +/* Mark the unused bytes as undefined */ +#define TC_UNDEFINE_SHRINK_VALGRIND_CHUNK(_tc, _new_size) do { \ + size_t _flen = (_tc)->size - (_new_size); \ + char *_fptr = (char *)TC_PTR_FROM_CHUNK(_tc); \ + _fptr += (_new_size); \ + VALGRIND_MAKE_MEM_UNDEFINED(_fptr, _flen); \ +} while (0) +#else +#define TC_UNDEFINE_SHRINK_VALGRIND_CHUNK(_tc, _new_size) do { } while (0) +#endif + +#define TC_UNDEFINE_SHRINK_CHUNK(_tc, _new_size) do { \ + TC_UNDEFINE_SHRINK_FILL_CHUNK(_tc, _new_size); \ + TC_UNDEFINE_SHRINK_VALGRIND_CHUNK(_tc, _new_size); \ +} while (0) + +#if defined(DEVELOPER) && defined(VALGRIND_MAKE_MEM_UNDEFINED) +/* Mark the new bytes as undefined */ +#define TC_UNDEFINE_GROW_VALGRIND_CHUNK(_tc, _new_size) do { \ + size_t _old_used = TC_HDR_SIZE + (_tc)->size; \ + size_t _new_used = TC_HDR_SIZE + (_new_size); \ + size_t _flen = _new_used - _old_used; \ + char *_fptr = _old_used + (char *)(_tc); \ + VALGRIND_MAKE_MEM_UNDEFINED(_fptr, _flen); \ +} while (0) +#else +#define TC_UNDEFINE_GROW_VALGRIND_CHUNK(_tc, _new_size) do { } while (0) +#endif + +#define TC_UNDEFINE_GROW_CHUNK(_tc, _new_size) do { \ + TC_UNDEFINE_GROW_VALGRIND_CHUNK(_tc, _new_size); \ +} while (0) + +struct talloc_reference_handle { + struct talloc_reference_handle *next, *prev; + void *ptr; + const char *location; +}; + +struct talloc_memlimit { + struct talloc_chunk *parent; + struct talloc_memlimit *upper; + size_t max_size; + size_t cur_size; +}; + +static inline bool talloc_memlimit_check(struct talloc_memlimit *limit, size_t size); +static inline void talloc_memlimit_grow(struct talloc_memlimit *limit, + size_t size); +static inline void talloc_memlimit_shrink(struct talloc_memlimit *limit, + size_t size); +static inline void tc_memlimit_update_on_free(struct talloc_chunk *tc); + +static inline void _tc_set_name_const(struct talloc_chunk *tc, + const char *name); +static struct talloc_chunk *_vasprintf_tc(const void *t, + const char *fmt, + va_list ap); + +typedef int (*talloc_destructor_t)(void *); + +struct talloc_pool_hdr; + +struct talloc_chunk { + /* + * flags includes the talloc magic, which is randomised to + * make overwrite attacks harder + */ + unsigned flags; + + /* + * If you have a logical tree like: + * + * <parent> + * / | \ + * / | \ + * / | \ + * <child 1> <child 2> <child 3> + * + * The actual talloc tree is: + * + * <parent> + * | + * <child 1> - <child 2> - <child 3> + * + * The children are linked with next/prev pointers, and + * child 1 is linked to the parent with parent/child + * pointers. + */ + + struct talloc_chunk *next, *prev; + struct talloc_chunk *parent, *child; + struct talloc_reference_handle *refs; + talloc_destructor_t destructor; + const char *name; + size_t size; + + /* + * limit semantics: + * if 'limit' is set it means all *new* children of the context will + * be limited to a total aggregate size ox max_size for memory + * allocations. + * cur_size is used to keep track of the current use + */ + struct talloc_memlimit *limit; + + /* + * For members of a pool (i.e. TALLOC_FLAG_POOLMEM is set), "pool" + * is a pointer to the struct talloc_chunk of the pool that it was + * allocated from. This way children can quickly find the pool to chew + * from. + */ + struct talloc_pool_hdr *pool; +}; + +union talloc_chunk_cast_u { + uint8_t *ptr; + struct talloc_chunk *chunk; +}; + +/* 16 byte alignment seems to keep everyone happy */ +#define TC_ALIGN16(s) (((s)+15)&~15) +#define TC_HDR_SIZE TC_ALIGN16(sizeof(struct talloc_chunk)) +#define TC_PTR_FROM_CHUNK(tc) ((void *)(TC_HDR_SIZE + (char*)tc)) + +_PUBLIC_ int talloc_version_major(void) +{ + return TALLOC_VERSION_MAJOR; +} + +_PUBLIC_ int talloc_version_minor(void) +{ + return TALLOC_VERSION_MINOR; +} + +_PUBLIC_ int talloc_test_get_magic(void) +{ + return talloc_magic; +} + +static inline void _talloc_chunk_set_free(struct talloc_chunk *tc, + const char *location) +{ + /* + * Mark this memory as free, and also over-stamp the talloc + * magic with the old-style magic. + * + * Why? This tries to avoid a memory read use-after-free from + * disclosing our talloc magic, which would then allow an + * attacker to prepare a valid header and so run a destructor. + * + */ + tc->flags = TALLOC_MAGIC_NON_RANDOM | TALLOC_FLAG_FREE + | (tc->flags & TALLOC_FLAG_MASK); + + /* we mark the freed memory with where we called the free + * from. This means on a double free error we can report where + * the first free came from + */ + if (location) { + tc->name = location; + } +} + +static inline void _talloc_chunk_set_not_free(struct talloc_chunk *tc) +{ + /* + * Mark this memory as not free. + * + * Why? This is memory either in a pool (and so available for + * talloc's re-use or after the realloc(). We need to mark + * the memory as free() before any realloc() call as we can't + * write to the memory after that. + * + * We put back the normal magic instead of the 'not random' + * magic. + */ + + tc->flags = talloc_magic | + ((tc->flags & TALLOC_FLAG_MASK) & ~TALLOC_FLAG_FREE); +} + +static void (*talloc_log_fn)(const char *message); + +_PUBLIC_ void talloc_set_log_fn(void (*log_fn)(const char *message)) +{ + talloc_log_fn = log_fn; +} + +#ifdef HAVE_CONSTRUCTOR_ATTRIBUTE +#define CONSTRUCTOR __attribute__((constructor)) +#elif defined(HAVE_PRAGMA_INIT) +#define CONSTRUCTOR +#pragma init (talloc_lib_init) +#endif +#if defined(HAVE_CONSTRUCTOR_ATTRIBUTE) || defined(HAVE_PRAGMA_INIT) +void talloc_lib_init(void) CONSTRUCTOR; +void talloc_lib_init(void) +{ + uint32_t random_value; +#if defined(HAVE_GETAUXVAL) && defined(AT_RANDOM) + uint8_t *p; + /* + * Use the kernel-provided random values used for + * ASLR. This won't change per-exec, which is ideal for us + */ + p = (uint8_t *) getauxval(AT_RANDOM); + if (p) { + /* + * We get 16 bytes from getauxval. By calling rand(), + * a totally insecure PRNG, but one that will + * deterministically have a different value when called + * twice, we ensure that if two talloc-like libraries + * are somehow loaded in the same address space, that + * because we choose different bytes, we will keep the + * protection against collision of multiple talloc + * libs. + * + * This protection is important because the effects of + * passing a talloc pointer from one to the other may + * be very hard to determine. + */ + int offset = rand() % (16 - sizeof(random_value)); + memcpy(&random_value, p + offset, sizeof(random_value)); + } else +#endif + { + /* + * Otherwise, hope the location we are loaded in + * memory is randomised by someone else + */ + random_value = ((uintptr_t)talloc_lib_init & 0xFFFFFFFF); + } + talloc_magic = random_value & ~TALLOC_FLAG_MASK; +} +#else +#warning "No __attribute__((constructor)) support found on this platform, additional talloc security measures not available" +#endif + +static void talloc_lib_atexit(void) +{ + TALLOC_FREE(autofree_context); + + if (talloc_total_size(null_context) == 0) { + return; + } + + if (talloc_report_null_full) { + talloc_report_full(null_context, stderr); + } else if (talloc_report_null) { + talloc_report(null_context, stderr); + } +} + +static void talloc_setup_atexit(void) +{ + static bool done; + + if (done) { + return; + } + + atexit(talloc_lib_atexit); + done = true; +} + +static void talloc_log(const char *fmt, ...) PRINTF_ATTRIBUTE(1,2); +static void talloc_log(const char *fmt, ...) +{ + va_list ap; + char *message; + + if (!talloc_log_fn) { + return; + } + + va_start(ap, fmt); + message = talloc_vasprintf(NULL, fmt, ap); + va_end(ap); + + talloc_log_fn(message); + talloc_free(message); +} + +static void talloc_log_stderr(const char *message) +{ + fprintf(stderr, "%s", message); +} + +_PUBLIC_ void talloc_set_log_stderr(void) +{ + talloc_set_log_fn(talloc_log_stderr); +} + +static void (*talloc_abort_fn)(const char *reason); + +_PUBLIC_ void talloc_set_abort_fn(void (*abort_fn)(const char *reason)) +{ + talloc_abort_fn = abort_fn; +} + +static void talloc_abort(const char *reason) +{ + talloc_log("%s\n", reason); + + if (!talloc_abort_fn) { + TALLOC_ABORT(reason); + } + + talloc_abort_fn(reason); +} + +static void talloc_abort_access_after_free(void) +{ + talloc_abort("Bad talloc magic value - access after free"); +} + +static void talloc_abort_unknown_value(void) +{ + talloc_abort("Bad talloc magic value - unknown value"); +} + +/* panic if we get a bad magic value */ +static inline struct talloc_chunk *talloc_chunk_from_ptr(const void *ptr) +{ + const char *pp = (const char *)ptr; + struct talloc_chunk *tc = discard_const_p(struct talloc_chunk, pp - TC_HDR_SIZE); + if (unlikely((tc->flags & (TALLOC_FLAG_FREE | ~TALLOC_FLAG_MASK)) != talloc_magic)) { + if ((tc->flags & (TALLOC_FLAG_FREE | ~TALLOC_FLAG_MASK)) + == (TALLOC_MAGIC_NON_RANDOM | TALLOC_FLAG_FREE)) { + talloc_log("talloc: access after free error - first free may be at %s\n", tc->name); + talloc_abort_access_after_free(); + return NULL; + } + + talloc_abort_unknown_value(); + return NULL; + } + return tc; +} + +/* hook into the front of the list */ +#define _TLIST_ADD(list, p) \ +do { \ + if (!(list)) { \ + (list) = (p); \ + (p)->next = (p)->prev = NULL; \ + } else { \ + (list)->prev = (p); \ + (p)->next = (list); \ + (p)->prev = NULL; \ + (list) = (p); \ + }\ +} while (0) + +/* remove an element from a list - element doesn't have to be in list. */ +#define _TLIST_REMOVE(list, p) \ +do { \ + if ((p) == (list)) { \ + (list) = (p)->next; \ + if (list) (list)->prev = NULL; \ + } else { \ + if ((p)->prev) (p)->prev->next = (p)->next; \ + if ((p)->next) (p)->next->prev = (p)->prev; \ + } \ + if ((p) && ((p) != (list))) (p)->next = (p)->prev = NULL; \ +} while (0) + + +/* + return the parent chunk of a pointer +*/ +static inline struct talloc_chunk *talloc_parent_chunk(const void *ptr) +{ + struct talloc_chunk *tc; + + if (unlikely(ptr == NULL)) { + return NULL; + } + + tc = talloc_chunk_from_ptr(ptr); + while (tc->prev) tc=tc->prev; + + return tc->parent; +} + +_PUBLIC_ void *talloc_parent(const void *ptr) +{ + struct talloc_chunk *tc = talloc_parent_chunk(ptr); + return tc? TC_PTR_FROM_CHUNK(tc) : NULL; +} + +/* + find parents name +*/ +_PUBLIC_ const char *talloc_parent_name(const void *ptr) +{ + struct talloc_chunk *tc = talloc_parent_chunk(ptr); + return tc? tc->name : NULL; +} + +/* + A pool carries an in-pool object count count in the first 16 bytes. + bytes. This is done to support talloc_steal() to a parent outside of the + pool. The count includes the pool itself, so a talloc_free() on a pool will + only destroy the pool if the count has dropped to zero. A talloc_free() of a + pool member will reduce the count, and eventually also call free(3) on the + pool memory. + + The object count is not put into "struct talloc_chunk" because it is only + relevant for talloc pools and the alignment to 16 bytes would increase the + memory footprint of each talloc chunk by those 16 bytes. +*/ + +struct talloc_pool_hdr { + void *end; + unsigned int object_count; + size_t poolsize; +}; + +union talloc_pool_hdr_cast_u { + uint8_t *ptr; + struct talloc_pool_hdr *hdr; +}; + +#define TP_HDR_SIZE TC_ALIGN16(sizeof(struct talloc_pool_hdr)) + +static inline struct talloc_pool_hdr *talloc_pool_from_chunk(struct talloc_chunk *c) +{ + union talloc_chunk_cast_u tcc = { .chunk = c }; + union talloc_pool_hdr_cast_u tphc = { tcc.ptr - TP_HDR_SIZE }; + return tphc.hdr; +} + +static inline struct talloc_chunk *talloc_chunk_from_pool(struct talloc_pool_hdr *h) +{ + union talloc_pool_hdr_cast_u tphc = { .hdr = h }; + union talloc_chunk_cast_u tcc = { .ptr = tphc.ptr + TP_HDR_SIZE }; + return tcc.chunk; +} + +static inline void *tc_pool_end(struct talloc_pool_hdr *pool_hdr) +{ + struct talloc_chunk *tc = talloc_chunk_from_pool(pool_hdr); + return (char *)tc + TC_HDR_SIZE + pool_hdr->poolsize; +} + +static inline size_t tc_pool_space_left(struct talloc_pool_hdr *pool_hdr) +{ + return (char *)tc_pool_end(pool_hdr) - (char *)pool_hdr->end; +} + +/* If tc is inside a pool, this gives the next neighbour. */ +static inline void *tc_next_chunk(struct talloc_chunk *tc) +{ + return (char *)tc + TC_ALIGN16(TC_HDR_SIZE + tc->size); +} + +static inline void *tc_pool_first_chunk(struct talloc_pool_hdr *pool_hdr) +{ + struct talloc_chunk *tc = talloc_chunk_from_pool(pool_hdr); + return tc_next_chunk(tc); +} + +/* Mark the whole remaining pool as not accessible */ +static inline void tc_invalidate_pool(struct talloc_pool_hdr *pool_hdr) +{ + size_t flen = tc_pool_space_left(pool_hdr); + + if (unlikely(talloc_fill.enabled)) { + memset(pool_hdr->end, talloc_fill.fill_value, flen); + } + +#if defined(DEVELOPER) && defined(VALGRIND_MAKE_MEM_NOACCESS) + VALGRIND_MAKE_MEM_NOACCESS(pool_hdr->end, flen); +#endif +} + +/* + Allocate from a pool +*/ + +static inline struct talloc_chunk *tc_alloc_pool(struct talloc_chunk *parent, + size_t size, size_t prefix_len) +{ + struct talloc_pool_hdr *pool_hdr = NULL; + union talloc_chunk_cast_u tcc; + size_t space_left; + struct talloc_chunk *result; + size_t chunk_size; + + if (parent == NULL) { + return NULL; + } + + if (parent->flags & TALLOC_FLAG_POOL) { + pool_hdr = talloc_pool_from_chunk(parent); + } + else if (parent->flags & TALLOC_FLAG_POOLMEM) { + pool_hdr = parent->pool; + } + + if (pool_hdr == NULL) { + return NULL; + } + + space_left = tc_pool_space_left(pool_hdr); + + /* + * Align size to 16 bytes + */ + chunk_size = TC_ALIGN16(size + prefix_len); + + if (space_left < chunk_size) { + return NULL; + } + + tcc = (union talloc_chunk_cast_u) { + .ptr = ((uint8_t *)pool_hdr->end) + prefix_len + }; + result = tcc.chunk; + +#if defined(DEVELOPER) && defined(VALGRIND_MAKE_MEM_UNDEFINED) + VALGRIND_MAKE_MEM_UNDEFINED(pool_hdr->end, chunk_size); +#endif + + pool_hdr->end = (void *)((char *)pool_hdr->end + chunk_size); + + result->flags = talloc_magic | TALLOC_FLAG_POOLMEM; + result->pool = pool_hdr; + + pool_hdr->object_count++; + + return result; +} + +/* + Allocate a bit of memory as a child of an existing pointer +*/ +static inline void *__talloc_with_prefix(const void *context, + size_t size, + size_t prefix_len, + struct talloc_chunk **tc_ret) +{ + struct talloc_chunk *tc = NULL; + struct talloc_memlimit *limit = NULL; + size_t total_len = TC_HDR_SIZE + size + prefix_len; + struct talloc_chunk *parent = NULL; + + if (unlikely(context == NULL)) { + context = null_context; + } + + if (unlikely(size >= MAX_TALLOC_SIZE)) { + return NULL; + } + + if (unlikely(total_len < TC_HDR_SIZE)) { + return NULL; + } + + if (likely(context != NULL)) { + parent = talloc_chunk_from_ptr(context); + + if (parent->limit != NULL) { + limit = parent->limit; + } + + tc = tc_alloc_pool(parent, TC_HDR_SIZE+size, prefix_len); + } + + if (tc == NULL) { + uint8_t *ptr = NULL; + union talloc_chunk_cast_u tcc; + + /* + * Only do the memlimit check/update on actual allocation. + */ + if (!talloc_memlimit_check(limit, total_len)) { + errno = ENOMEM; + return NULL; + } + + ptr = malloc(total_len); + if (unlikely(ptr == NULL)) { + return NULL; + } + tcc = (union talloc_chunk_cast_u) { .ptr = ptr + prefix_len }; + tc = tcc.chunk; + tc->flags = talloc_magic; + tc->pool = NULL; + + talloc_memlimit_grow(limit, total_len); + } + + tc->limit = limit; + tc->size = size; + tc->destructor = NULL; + tc->child = NULL; + tc->name = NULL; + tc->refs = NULL; + + if (likely(context != NULL)) { + if (parent->child) { + parent->child->parent = NULL; + tc->next = parent->child; + tc->next->prev = tc; + } else { + tc->next = NULL; + } + tc->parent = parent; + tc->prev = NULL; + parent->child = tc; + } else { + tc->next = tc->prev = tc->parent = NULL; + } + + *tc_ret = tc; + return TC_PTR_FROM_CHUNK(tc); +} + +static inline void *__talloc(const void *context, + size_t size, + struct talloc_chunk **tc) +{ + return __talloc_with_prefix(context, size, 0, tc); +} + +/* + * Create a talloc pool + */ + +static inline void *_talloc_pool(const void *context, size_t size) +{ + struct talloc_chunk *tc = NULL; + struct talloc_pool_hdr *pool_hdr; + void *result; + + result = __talloc_with_prefix(context, size, TP_HDR_SIZE, &tc); + + if (unlikely(result == NULL)) { + return NULL; + } + + pool_hdr = talloc_pool_from_chunk(tc); + + tc->flags |= TALLOC_FLAG_POOL; + tc->size = 0; + + pool_hdr->object_count = 1; + pool_hdr->end = result; + pool_hdr->poolsize = size; + + tc_invalidate_pool(pool_hdr); + + return result; +} + +_PUBLIC_ void *talloc_pool(const void *context, size_t size) +{ + return _talloc_pool(context, size); +} + +/* + * Create a talloc pool correctly sized for a basic size plus + * a number of subobjects whose total size is given. Essentially + * a custom allocator for talloc to reduce fragmentation. + */ + +_PUBLIC_ void *_talloc_pooled_object(const void *ctx, + size_t type_size, + const char *type_name, + unsigned num_subobjects, + size_t total_subobjects_size) +{ + size_t poolsize, subobjects_slack, tmp; + struct talloc_chunk *tc; + struct talloc_pool_hdr *pool_hdr; + void *ret; + + poolsize = type_size + total_subobjects_size; + + if ((poolsize < type_size) || (poolsize < total_subobjects_size)) { + goto overflow; + } + + if (num_subobjects == UINT_MAX) { + goto overflow; + } + num_subobjects += 1; /* the object body itself */ + + /* + * Alignment can increase the pool size by at most 15 bytes per object + * plus alignment for the object itself + */ + subobjects_slack = (TC_HDR_SIZE + TP_HDR_SIZE + 15) * num_subobjects; + if (subobjects_slack < num_subobjects) { + goto overflow; + } + + tmp = poolsize + subobjects_slack; + if ((tmp < poolsize) || (tmp < subobjects_slack)) { + goto overflow; + } + poolsize = tmp; + + ret = _talloc_pool(ctx, poolsize); + if (ret == NULL) { + return NULL; + } + + tc = talloc_chunk_from_ptr(ret); + tc->size = type_size; + + pool_hdr = talloc_pool_from_chunk(tc); + +#if defined(DEVELOPER) && defined(VALGRIND_MAKE_MEM_UNDEFINED) + VALGRIND_MAKE_MEM_UNDEFINED(pool_hdr->end, type_size); +#endif + + pool_hdr->end = ((char *)pool_hdr->end + TC_ALIGN16(type_size)); + + _tc_set_name_const(tc, type_name); + return ret; + +overflow: + return NULL; +} + +/* + setup a destructor to be called on free of a pointer + the destructor should return 0 on success, or -1 on failure. + if the destructor fails then the free is failed, and the memory can + be continued to be used +*/ +_PUBLIC_ void _talloc_set_destructor(const void *ptr, int (*destructor)(void *)) +{ + struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); + tc->destructor = destructor; +} + +/* + increase the reference count on a piece of memory. +*/ +_PUBLIC_ int talloc_increase_ref_count(const void *ptr) +{ + if (unlikely(!talloc_reference(null_context, ptr))) { + return -1; + } + return 0; +} + +/* + helper for talloc_reference() + + this is referenced by a function pointer and should not be inline +*/ +static int talloc_reference_destructor(struct talloc_reference_handle *handle) +{ + struct talloc_chunk *ptr_tc = talloc_chunk_from_ptr(handle->ptr); + _TLIST_REMOVE(ptr_tc->refs, handle); + return 0; +} + +/* + more efficient way to add a name to a pointer - the name must point to a + true string constant +*/ +static inline void _tc_set_name_const(struct talloc_chunk *tc, + const char *name) +{ + tc->name = name; +} + +/* + internal talloc_named_const() +*/ +static inline void *_talloc_named_const(const void *context, size_t size, const char *name) +{ + void *ptr; + struct talloc_chunk *tc = NULL; + + ptr = __talloc(context, size, &tc); + if (unlikely(ptr == NULL)) { + return NULL; + } + + _tc_set_name_const(tc, name); + + return ptr; +} + +/* + make a secondary reference to a pointer, hanging off the given context. + the pointer remains valid until both the original caller and this given + context are freed. + + the major use for this is when two different structures need to reference the + same underlying data, and you want to be able to free the two instances separately, + and in either order +*/ +_PUBLIC_ void *_talloc_reference_loc(const void *context, const void *ptr, const char *location) +{ + struct talloc_chunk *tc; + struct talloc_reference_handle *handle; + if (unlikely(ptr == NULL)) return NULL; + + tc = talloc_chunk_from_ptr(ptr); + handle = (struct talloc_reference_handle *)_talloc_named_const(context, + sizeof(struct talloc_reference_handle), + TALLOC_MAGIC_REFERENCE); + if (unlikely(handle == NULL)) return NULL; + + /* note that we hang the destructor off the handle, not the + main context as that allows the caller to still setup their + own destructor on the context if they want to */ + talloc_set_destructor(handle, talloc_reference_destructor); + handle->ptr = discard_const_p(void, ptr); + handle->location = location; + _TLIST_ADD(tc->refs, handle); + return handle->ptr; +} + +static void *_talloc_steal_internal(const void *new_ctx, const void *ptr); + +static inline void _tc_free_poolmem(struct talloc_chunk *tc, + const char *location) +{ + struct talloc_pool_hdr *pool; + struct talloc_chunk *pool_tc; + void *next_tc; + + pool = tc->pool; + pool_tc = talloc_chunk_from_pool(pool); + next_tc = tc_next_chunk(tc); + + _talloc_chunk_set_free(tc, location); + + TC_INVALIDATE_FULL_CHUNK(tc); + + if (unlikely(pool->object_count == 0)) { + talloc_abort("Pool object count zero!"); + return; + } + + pool->object_count--; + + if (unlikely(pool->object_count == 1 + && !(pool_tc->flags & TALLOC_FLAG_FREE))) { + /* + * if there is just one object left in the pool + * and pool->flags does not have TALLOC_FLAG_FREE, + * it means this is the pool itself and + * the rest is available for new objects + * again. + */ + pool->end = tc_pool_first_chunk(pool); + tc_invalidate_pool(pool); + return; + } + + if (unlikely(pool->object_count == 0)) { + /* + * we mark the freed memory with where we called the free + * from. This means on a double free error we can report where + * the first free came from + */ + pool_tc->name = location; + + if (pool_tc->flags & TALLOC_FLAG_POOLMEM) { + _tc_free_poolmem(pool_tc, location); + } else { + /* + * The tc_memlimit_update_on_free() + * call takes into account the + * prefix TP_HDR_SIZE allocated before + * the pool talloc_chunk. + */ + tc_memlimit_update_on_free(pool_tc); + TC_INVALIDATE_FULL_CHUNK(pool_tc); + free(pool); + } + return; + } + + if (pool->end == next_tc) { + /* + * if pool->pool still points to end of + * 'tc' (which is stored in the 'next_tc' variable), + * we can reclaim the memory of 'tc'. + */ + pool->end = tc; + return; + } + + /* + * Do nothing. The memory is just "wasted", waiting for the pool + * itself to be freed. + */ +} + +static inline void _tc_free_children_internal(struct talloc_chunk *tc, + void *ptr, + const char *location); + +static inline int _talloc_free_internal(void *ptr, const char *location); + +/* + internal free call that takes a struct talloc_chunk *. +*/ +static inline int _tc_free_internal(struct talloc_chunk *tc, + const char *location) +{ + void *ptr_to_free; + void *ptr = TC_PTR_FROM_CHUNK(tc); + + if (unlikely(tc->refs)) { + int is_child; + /* check if this is a reference from a child or + * grandchild back to it's parent or grandparent + * + * in that case we need to remove the reference and + * call another instance of talloc_free() on the current + * pointer. + */ + is_child = talloc_is_parent(tc->refs, ptr); + _talloc_free_internal(tc->refs, location); + if (is_child) { + return _talloc_free_internal(ptr, location); + } + return -1; + } + + if (unlikely(tc->flags & TALLOC_FLAG_LOOP)) { + /* we have a free loop - stop looping */ + return 0; + } + + if (unlikely(tc->destructor)) { + talloc_destructor_t d = tc->destructor; + + /* + * Protect the destructor against some overwrite + * attacks, by explicitly checking it has the right + * magic here. + */ + if (talloc_chunk_from_ptr(ptr) != tc) { + /* + * This can't actually happen, the + * call itself will panic. + */ + TALLOC_ABORT("talloc_chunk_from_ptr failed!"); + } + + if (d == (talloc_destructor_t)-1) { + return -1; + } + tc->destructor = (talloc_destructor_t)-1; + if (d(ptr) == -1) { + /* + * Only replace the destructor pointer if + * calling the destructor didn't modify it. + */ + if (tc->destructor == (talloc_destructor_t)-1) { + tc->destructor = d; + } + return -1; + } + tc->destructor = NULL; + } + + if (tc->parent) { + _TLIST_REMOVE(tc->parent->child, tc); + if (tc->parent->child) { + tc->parent->child->parent = tc->parent; + } + } else { + if (tc->prev) tc->prev->next = tc->next; + if (tc->next) tc->next->prev = tc->prev; + tc->prev = tc->next = NULL; + } + + tc->flags |= TALLOC_FLAG_LOOP; + + _tc_free_children_internal(tc, ptr, location); + + _talloc_chunk_set_free(tc, location); + + if (tc->flags & TALLOC_FLAG_POOL) { + struct talloc_pool_hdr *pool; + + pool = talloc_pool_from_chunk(tc); + + if (unlikely(pool->object_count == 0)) { + talloc_abort("Pool object count zero!"); + return 0; + } + + pool->object_count--; + + if (likely(pool->object_count != 0)) { + return 0; + } + + /* + * With object_count==0, a pool becomes a normal piece of + * memory to free. If it's allocated inside a pool, it needs + * to be freed as poolmem, else it needs to be just freed. + */ + ptr_to_free = pool; + } else { + ptr_to_free = tc; + } + + if (tc->flags & TALLOC_FLAG_POOLMEM) { + _tc_free_poolmem(tc, location); + return 0; + } + + tc_memlimit_update_on_free(tc); + + TC_INVALIDATE_FULL_CHUNK(tc); + free(ptr_to_free); + return 0; +} + +/* + internal talloc_free call +*/ +static inline int _talloc_free_internal(void *ptr, const char *location) +{ + struct talloc_chunk *tc; + + if (unlikely(ptr == NULL)) { + return -1; + } + + /* possibly initialised the talloc fill value */ + if (unlikely(!talloc_fill.initialised)) { + const char *fill = getenv(TALLOC_FILL_ENV); + if (fill != NULL) { + talloc_fill.enabled = true; + talloc_fill.fill_value = strtoul(fill, NULL, 0); + } + talloc_fill.initialised = true; + } + + tc = talloc_chunk_from_ptr(ptr); + return _tc_free_internal(tc, location); +} + +static inline size_t _talloc_total_limit_size(const void *ptr, + struct talloc_memlimit *old_limit, + struct talloc_memlimit *new_limit); + +/* + move a lump of memory from one talloc context to another returning the + ptr on success, or NULL if it could not be transferred. + passing NULL as ptr will always return NULL with no side effects. +*/ +static void *_talloc_steal_internal(const void *new_ctx, const void *ptr) +{ + struct talloc_chunk *tc, *new_tc; + size_t ctx_size = 0; + + if (unlikely(!ptr)) { + return NULL; + } + + if (unlikely(new_ctx == NULL)) { + new_ctx = null_context; + } + + tc = talloc_chunk_from_ptr(ptr); + + if (tc->limit != NULL) { + + ctx_size = _talloc_total_limit_size(ptr, NULL, NULL); + + /* Decrement the memory limit from the source .. */ + talloc_memlimit_shrink(tc->limit->upper, ctx_size); + + if (tc->limit->parent == tc) { + tc->limit->upper = NULL; + } else { + tc->limit = NULL; + } + } + + if (unlikely(new_ctx == NULL)) { + if (tc->parent) { + _TLIST_REMOVE(tc->parent->child, tc); + if (tc->parent->child) { + tc->parent->child->parent = tc->parent; + } + } else { + if (tc->prev) tc->prev->next = tc->next; + if (tc->next) tc->next->prev = tc->prev; + } + + tc->parent = tc->next = tc->prev = NULL; + return discard_const_p(void, ptr); + } + + new_tc = talloc_chunk_from_ptr(new_ctx); + + if (unlikely(tc == new_tc || tc->parent == new_tc)) { + return discard_const_p(void, ptr); + } + + if (tc->parent) { + _TLIST_REMOVE(tc->parent->child, tc); + if (tc->parent->child) { + tc->parent->child->parent = tc->parent; + } + } else { + if (tc->prev) tc->prev->next = tc->next; + if (tc->next) tc->next->prev = tc->prev; + tc->prev = tc->next = NULL; + } + + tc->parent = new_tc; + if (new_tc->child) new_tc->child->parent = NULL; + _TLIST_ADD(new_tc->child, tc); + + if (tc->limit || new_tc->limit) { + ctx_size = _talloc_total_limit_size(ptr, tc->limit, + new_tc->limit); + /* .. and increment it in the destination. */ + if (new_tc->limit) { + talloc_memlimit_grow(new_tc->limit, ctx_size); + } + } + + return discard_const_p(void, ptr); +} + +/* + move a lump of memory from one talloc context to another returning the + ptr on success, or NULL if it could not be transferred. + passing NULL as ptr will always return NULL with no side effects. +*/ +_PUBLIC_ void *_talloc_steal_loc(const void *new_ctx, const void *ptr, const char *location) +{ + struct talloc_chunk *tc; + + if (unlikely(ptr == NULL)) { + return NULL; + } + + tc = talloc_chunk_from_ptr(ptr); + + if (unlikely(tc->refs != NULL) && talloc_parent(ptr) != new_ctx) { + struct talloc_reference_handle *h; + + talloc_log("WARNING: talloc_steal with references at %s\n", + location); + + for (h=tc->refs; h; h=h->next) { + talloc_log("\treference at %s\n", + h->location); + } + } + +#if 0 + /* this test is probably too expensive to have on in the + normal build, but it useful for debugging */ + if (talloc_is_parent(new_ctx, ptr)) { + talloc_log("WARNING: stealing into talloc child at %s\n", location); + } +#endif + + return _talloc_steal_internal(new_ctx, ptr); +} + +/* + this is like a talloc_steal(), but you must supply the old + parent. This resolves the ambiguity in a talloc_steal() which is + called on a context that has more than one parent (via references) + + The old parent can be either a reference or a parent +*/ +_PUBLIC_ void *talloc_reparent(const void *old_parent, const void *new_parent, const void *ptr) +{ + struct talloc_chunk *tc; + struct talloc_reference_handle *h; + + if (unlikely(ptr == NULL)) { + return NULL; + } + + if (old_parent == talloc_parent(ptr)) { + return _talloc_steal_internal(new_parent, ptr); + } + + tc = talloc_chunk_from_ptr(ptr); + for (h=tc->refs;h;h=h->next) { + if (talloc_parent(h) == old_parent) { + if (_talloc_steal_internal(new_parent, h) != h) { + return NULL; + } + return discard_const_p(void, ptr); + } + } + + /* it wasn't a parent */ + return NULL; +} + +/* + remove a secondary reference to a pointer. This undo's what + talloc_reference() has done. The context and pointer arguments + must match those given to a talloc_reference() +*/ +static inline int talloc_unreference(const void *context, const void *ptr) +{ + struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); + struct talloc_reference_handle *h; + + if (unlikely(context == NULL)) { + context = null_context; + } + + for (h=tc->refs;h;h=h->next) { + struct talloc_chunk *p = talloc_parent_chunk(h); + if (p == NULL) { + if (context == NULL) break; + } else if (TC_PTR_FROM_CHUNK(p) == context) { + break; + } + } + if (h == NULL) { + return -1; + } + + return _talloc_free_internal(h, __location__); +} + +/* + remove a specific parent context from a pointer. This is a more + controlled variant of talloc_free() +*/ + +/* coverity[ -tainted_data_sink : arg-1 ] */ +_PUBLIC_ int talloc_unlink(const void *context, void *ptr) +{ + struct talloc_chunk *tc_p, *new_p, *tc_c; + void *new_parent; + + if (ptr == NULL) { + return -1; + } + + if (context == NULL) { + context = null_context; + } + + if (talloc_unreference(context, ptr) == 0) { + return 0; + } + + if (context != NULL) { + tc_c = talloc_chunk_from_ptr(context); + } else { + tc_c = NULL; + } + if (tc_c != talloc_parent_chunk(ptr)) { + return -1; + } + + tc_p = talloc_chunk_from_ptr(ptr); + + if (tc_p->refs == NULL) { + return _talloc_free_internal(ptr, __location__); + } + + new_p = talloc_parent_chunk(tc_p->refs); + if (new_p) { + new_parent = TC_PTR_FROM_CHUNK(new_p); + } else { + new_parent = NULL; + } + + if (talloc_unreference(new_parent, ptr) != 0) { + return -1; + } + + _talloc_steal_internal(new_parent, ptr); + + return 0; +} + +/* + add a name to an existing pointer - va_list version +*/ +static inline const char *tc_set_name_v(struct talloc_chunk *tc, + const char *fmt, + va_list ap) PRINTF_ATTRIBUTE(2,0); + +static inline const char *tc_set_name_v(struct talloc_chunk *tc, + const char *fmt, + va_list ap) +{ + struct talloc_chunk *name_tc = _vasprintf_tc(TC_PTR_FROM_CHUNK(tc), + fmt, + ap); + if (likely(name_tc)) { + tc->name = TC_PTR_FROM_CHUNK(name_tc); + _tc_set_name_const(name_tc, ".name"); + } else { + tc->name = NULL; + } + return tc->name; +} + +/* + add a name to an existing pointer +*/ +_PUBLIC_ const char *talloc_set_name(const void *ptr, const char *fmt, ...) +{ + struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); + const char *name; + va_list ap; + va_start(ap, fmt); + name = tc_set_name_v(tc, fmt, ap); + va_end(ap); + return name; +} + + +/* + create a named talloc pointer. Any talloc pointer can be named, and + talloc_named() operates just like talloc() except that it allows you + to name the pointer. +*/ +_PUBLIC_ void *talloc_named(const void *context, size_t size, const char *fmt, ...) +{ + va_list ap; + void *ptr; + const char *name; + struct talloc_chunk *tc = NULL; + + ptr = __talloc(context, size, &tc); + if (unlikely(ptr == NULL)) return NULL; + + va_start(ap, fmt); + name = tc_set_name_v(tc, fmt, ap); + va_end(ap); + + if (unlikely(name == NULL)) { + _talloc_free_internal(ptr, __location__); + return NULL; + } + + return ptr; +} + +/* + return the name of a talloc ptr, or "UNNAMED" +*/ +static inline const char *__talloc_get_name(const void *ptr) +{ + struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); + if (unlikely(tc->name == TALLOC_MAGIC_REFERENCE)) { + return ".reference"; + } + if (likely(tc->name)) { + return tc->name; + } + return "UNNAMED"; +} + +_PUBLIC_ const char *talloc_get_name(const void *ptr) +{ + return __talloc_get_name(ptr); +} + +/* + check if a pointer has the given name. If it does, return the pointer, + otherwise return NULL +*/ +_PUBLIC_ void *talloc_check_name(const void *ptr, const char *name) +{ + const char *pname; + if (unlikely(ptr == NULL)) return NULL; + pname = __talloc_get_name(ptr); + if (likely(pname == name || strcmp(pname, name) == 0)) { + return discard_const_p(void, ptr); + } + return NULL; +} + +static void talloc_abort_type_mismatch(const char *location, + const char *name, + const char *expected) +{ + const char *reason; + + reason = talloc_asprintf(NULL, + "%s: Type mismatch: name[%s] expected[%s]", + location, + name?name:"NULL", + expected); + if (!reason) { + reason = "Type mismatch"; + } + + talloc_abort(reason); +} + +_PUBLIC_ void *_talloc_get_type_abort(const void *ptr, const char *name, const char *location) +{ + const char *pname; + + if (unlikely(ptr == NULL)) { + talloc_abort_type_mismatch(location, NULL, name); + return NULL; + } + + pname = __talloc_get_name(ptr); + if (likely(pname == name || strcmp(pname, name) == 0)) { + return discard_const_p(void, ptr); + } + + talloc_abort_type_mismatch(location, pname, name); + return NULL; +} + +/* + this is for compatibility with older versions of talloc +*/ +_PUBLIC_ void *talloc_init(const char *fmt, ...) +{ + va_list ap; + void *ptr; + const char *name; + struct talloc_chunk *tc = NULL; + + ptr = __talloc(NULL, 0, &tc); + if (unlikely(ptr == NULL)) return NULL; + + va_start(ap, fmt); + name = tc_set_name_v(tc, fmt, ap); + va_end(ap); + + if (unlikely(name == NULL)) { + _talloc_free_internal(ptr, __location__); + return NULL; + } + + return ptr; +} + +static inline void _tc_free_children_internal(struct talloc_chunk *tc, + void *ptr, + const char *location) +{ + while (tc->child) { + /* we need to work out who will own an abandoned child + if it cannot be freed. In priority order, the first + choice is owner of any remaining reference to this + pointer, the second choice is our parent, and the + final choice is the null context. */ + void *child = TC_PTR_FROM_CHUNK(tc->child); + const void *new_parent = null_context; + if (unlikely(tc->child->refs)) { + struct talloc_chunk *p = talloc_parent_chunk(tc->child->refs); + if (p) new_parent = TC_PTR_FROM_CHUNK(p); + } + if (unlikely(_tc_free_internal(tc->child, location) == -1)) { + if (talloc_parent_chunk(child) != tc) { + /* + * Destructor already reparented this child. + * No further reparenting needed. + */ + continue; + } + if (new_parent == null_context) { + struct talloc_chunk *p = talloc_parent_chunk(ptr); + if (p) new_parent = TC_PTR_FROM_CHUNK(p); + } + _talloc_steal_internal(new_parent, child); + } + } +} + +/* + this is a replacement for the Samba3 talloc_destroy_pool functionality. It + should probably not be used in new code. It's in here to keep the talloc + code consistent across Samba 3 and 4. +*/ +_PUBLIC_ void talloc_free_children(void *ptr) +{ + struct talloc_chunk *tc_name = NULL; + struct talloc_chunk *tc; + + if (unlikely(ptr == NULL)) { + return; + } + + tc = talloc_chunk_from_ptr(ptr); + + /* we do not want to free the context name if it is a child .. */ + if (likely(tc->child)) { + for (tc_name = tc->child; tc_name; tc_name = tc_name->next) { + if (tc->name == TC_PTR_FROM_CHUNK(tc_name)) break; + } + if (tc_name) { + _TLIST_REMOVE(tc->child, tc_name); + if (tc->child) { + tc->child->parent = tc; + } + } + } + + _tc_free_children_internal(tc, ptr, __location__); + + /* .. so we put it back after all other children have been freed */ + if (tc_name) { + if (tc->child) { + tc->child->parent = NULL; + } + tc_name->parent = tc; + _TLIST_ADD(tc->child, tc_name); + } +} + +/* + Allocate a bit of memory as a child of an existing pointer +*/ +_PUBLIC_ void *_talloc(const void *context, size_t size) +{ + struct talloc_chunk *tc; + return __talloc(context, size, &tc); +} + +/* + externally callable talloc_set_name_const() +*/ +_PUBLIC_ void talloc_set_name_const(const void *ptr, const char *name) +{ + _tc_set_name_const(talloc_chunk_from_ptr(ptr), name); +} + +/* + create a named talloc pointer. Any talloc pointer can be named, and + talloc_named() operates just like talloc() except that it allows you + to name the pointer. +*/ +_PUBLIC_ void *talloc_named_const(const void *context, size_t size, const char *name) +{ + return _talloc_named_const(context, size, name); +} + +/* + free a talloc pointer. This also frees all child pointers of this + pointer recursively + + return 0 if the memory is actually freed, otherwise -1. The memory + will not be freed if the ref_count is > 1 or the destructor (if + any) returns non-zero +*/ +_PUBLIC_ int _talloc_free(void *ptr, const char *location) +{ + struct talloc_chunk *tc; + + if (unlikely(ptr == NULL)) { + return -1; + } + + tc = talloc_chunk_from_ptr(ptr); + + if (unlikely(tc->refs != NULL)) { + struct talloc_reference_handle *h; + + if (talloc_parent(ptr) == null_context && tc->refs->next == NULL) { + /* in this case we do know which parent should + get this pointer, as there is really only + one parent */ + return talloc_unlink(null_context, ptr); + } + + talloc_log("ERROR: talloc_free with references at %s\n", + location); + + for (h=tc->refs; h; h=h->next) { + talloc_log("\treference at %s\n", + h->location); + } + return -1; + } + + return _talloc_free_internal(ptr, location); +} + + + +/* + A talloc version of realloc. The context argument is only used if + ptr is NULL +*/ +_PUBLIC_ void *_talloc_realloc(const void *context, void *ptr, size_t size, const char *name) +{ + struct talloc_chunk *tc; + void *new_ptr; + bool malloced = false; + struct talloc_pool_hdr *pool_hdr = NULL; + size_t old_size = 0; + size_t new_size = 0; + + /* size zero is equivalent to free() */ + if (unlikely(size == 0)) { + talloc_unlink(context, ptr); + return NULL; + } + + if (unlikely(size >= MAX_TALLOC_SIZE)) { + return NULL; + } + + /* realloc(NULL) is equivalent to malloc() */ + if (ptr == NULL) { + return _talloc_named_const(context, size, name); + } + + tc = talloc_chunk_from_ptr(ptr); + + /* don't allow realloc on referenced pointers */ + if (unlikely(tc->refs)) { + return NULL; + } + + /* don't let anybody try to realloc a talloc_pool */ + if (unlikely(tc->flags & TALLOC_FLAG_POOL)) { + return NULL; + } + + /* handle realloc inside a talloc_pool */ + if (unlikely(tc->flags & TALLOC_FLAG_POOLMEM)) { + pool_hdr = tc->pool; + } + + /* don't shrink if we have less than 1k to gain */ + if (size < tc->size && tc->limit == NULL) { + if (pool_hdr) { + void *next_tc = tc_next_chunk(tc); + TC_INVALIDATE_SHRINK_CHUNK(tc, size); + tc->size = size; + if (next_tc == pool_hdr->end) { + /* note: tc->size has changed, so this works */ + pool_hdr->end = tc_next_chunk(tc); + } + return ptr; + } else if ((tc->size - size) < 1024) { + /* + * if we call TC_INVALIDATE_SHRINK_CHUNK() here + * we would need to call TC_UNDEFINE_GROW_CHUNK() + * after each realloc call, which slows down + * testing a lot :-(. + * + * That is why we only mark memory as undefined here. + */ + TC_UNDEFINE_SHRINK_CHUNK(tc, size); + + /* do not shrink if we have less than 1k to gain */ + tc->size = size; + return ptr; + } + } else if (tc->size == size) { + /* + * do not change the pointer if it is exactly + * the same size. + */ + return ptr; + } + + /* + * by resetting magic we catch users of the old memory + * + * We mark this memory as free, and also over-stamp the talloc + * magic with the old-style magic. + * + * Why? This tries to avoid a memory read use-after-free from + * disclosing our talloc magic, which would then allow an + * attacker to prepare a valid header and so run a destructor. + * + * What else? We have to re-stamp back a valid normal magic + * on this memory once realloc() is done, as it will have done + * a memcpy() into the new valid memory. We can't do this in + * reverse as that would be a real use-after-free. + */ + _talloc_chunk_set_free(tc, NULL); + + if (pool_hdr) { + struct talloc_chunk *pool_tc; + void *next_tc = tc_next_chunk(tc); + size_t old_chunk_size = TC_ALIGN16(TC_HDR_SIZE + tc->size); + size_t new_chunk_size = TC_ALIGN16(TC_HDR_SIZE + size); + size_t space_needed; + size_t space_left; + unsigned int chunk_count = pool_hdr->object_count; + + pool_tc = talloc_chunk_from_pool(pool_hdr); + if (!(pool_tc->flags & TALLOC_FLAG_FREE)) { + chunk_count -= 1; + } + + if (chunk_count == 1) { + /* + * optimize for the case where 'tc' is the only + * chunk in the pool. + */ + char *start = tc_pool_first_chunk(pool_hdr); + space_needed = new_chunk_size; + space_left = (char *)tc_pool_end(pool_hdr) - start; + + if (space_left >= space_needed) { + size_t old_used = TC_HDR_SIZE + tc->size; + size_t new_used = TC_HDR_SIZE + size; + new_ptr = start; + +#if defined(DEVELOPER) && defined(VALGRIND_MAKE_MEM_UNDEFINED) + { + /* + * The area from + * start -> tc may have + * been freed and thus been marked as + * VALGRIND_MEM_NOACCESS. Set it to + * VALGRIND_MEM_UNDEFINED so we can + * copy into it without valgrind errors. + * We can't just mark + * new_ptr -> new_ptr + old_used + * as this may overlap on top of tc, + * (which is why we use memmove, not + * memcpy below) hence the MIN. + */ + size_t undef_len = MIN((((char *)tc) - ((char *)new_ptr)),old_used); + VALGRIND_MAKE_MEM_UNDEFINED(new_ptr, undef_len); + } +#endif + + memmove(new_ptr, tc, old_used); + + tc = (struct talloc_chunk *)new_ptr; + TC_UNDEFINE_GROW_CHUNK(tc, size); + + /* + * first we do not align the pool pointer + * because we want to invalidate the padding + * too. + */ + pool_hdr->end = new_used + (char *)new_ptr; + tc_invalidate_pool(pool_hdr); + + /* now the aligned pointer */ + pool_hdr->end = new_chunk_size + (char *)new_ptr; + goto got_new_ptr; + } + + next_tc = NULL; + } + + if (new_chunk_size == old_chunk_size) { + TC_UNDEFINE_GROW_CHUNK(tc, size); + _talloc_chunk_set_not_free(tc); + tc->size = size; + return ptr; + } + + if (next_tc == pool_hdr->end) { + /* + * optimize for the case where 'tc' is the last + * chunk in the pool. + */ + space_needed = new_chunk_size - old_chunk_size; + space_left = tc_pool_space_left(pool_hdr); + + if (space_left >= space_needed) { + TC_UNDEFINE_GROW_CHUNK(tc, size); + _talloc_chunk_set_not_free(tc); + tc->size = size; + pool_hdr->end = tc_next_chunk(tc); + return ptr; + } + } + + new_ptr = tc_alloc_pool(tc, size + TC_HDR_SIZE, 0); + + if (new_ptr == NULL) { + /* + * Couldn't allocate from pool (pool size + * counts as already allocated for memlimit + * purposes). We must check memory limit + * before any real malloc. + */ + if (tc->limit) { + /* + * Note we're doing an extra malloc, + * on top of the pool size, so account + * for size only, not the difference + * between old and new size. + */ + if (!talloc_memlimit_check(tc->limit, size)) { + _talloc_chunk_set_not_free(tc); + errno = ENOMEM; + return NULL; + } + } + new_ptr = malloc(TC_HDR_SIZE+size); + malloced = true; + new_size = size; + } + + if (new_ptr) { + memcpy(new_ptr, tc, MIN(tc->size,size) + TC_HDR_SIZE); + + _tc_free_poolmem(tc, __location__ "_talloc_realloc"); + } + } + else { + /* We're doing realloc here, so record the difference. */ + old_size = tc->size; + new_size = size; + /* + * We must check memory limit + * before any real realloc. + */ + if (tc->limit && (size > old_size)) { + if (!talloc_memlimit_check(tc->limit, + (size - old_size))) { + _talloc_chunk_set_not_free(tc); + errno = ENOMEM; + return NULL; + } + } + new_ptr = realloc(tc, size + TC_HDR_SIZE); + } +got_new_ptr: + + if (unlikely(!new_ptr)) { + /* + * Ok, this is a strange spot. We have to put back + * the old talloc_magic and any flags, except the + * TALLOC_FLAG_FREE as this was not free'ed by the + * realloc() call after all + */ + _talloc_chunk_set_not_free(tc); + return NULL; + } + + /* + * tc is now the new value from realloc(), the old memory we + * can't access any more and was preemptively marked as + * TALLOC_FLAG_FREE before the call. Now we mark it as not + * free again + */ + tc = (struct talloc_chunk *)new_ptr; + _talloc_chunk_set_not_free(tc); + if (malloced) { + tc->flags &= ~TALLOC_FLAG_POOLMEM; + } + if (tc->parent) { + tc->parent->child = tc; + } + if (tc->child) { + tc->child->parent = tc; + } + + if (tc->prev) { + tc->prev->next = tc; + } + if (tc->next) { + tc->next->prev = tc; + } + + if (new_size > old_size) { + talloc_memlimit_grow(tc->limit, new_size - old_size); + } else if (new_size < old_size) { + talloc_memlimit_shrink(tc->limit, old_size - new_size); + } + + tc->size = size; + _tc_set_name_const(tc, name); + + return TC_PTR_FROM_CHUNK(tc); +} + +/* + a wrapper around talloc_steal() for situations where you are moving a pointer + between two structures, and want the old pointer to be set to NULL +*/ +_PUBLIC_ void *_talloc_move(const void *new_ctx, const void *_pptr) +{ + const void **pptr = discard_const_p(const void *,_pptr); + void *ret = talloc_steal(new_ctx, discard_const_p(void, *pptr)); + (*pptr) = NULL; + return ret; +} + +enum talloc_mem_count_type { + TOTAL_MEM_SIZE, + TOTAL_MEM_BLOCKS, + TOTAL_MEM_LIMIT, +}; + +static inline size_t _talloc_total_mem_internal(const void *ptr, + enum talloc_mem_count_type type, + struct talloc_memlimit *old_limit, + struct talloc_memlimit *new_limit) +{ + size_t total = 0; + struct talloc_chunk *c, *tc; + + if (ptr == NULL) { + ptr = null_context; + } + if (ptr == NULL) { + return 0; + } + + tc = talloc_chunk_from_ptr(ptr); + + if (old_limit || new_limit) { + if (tc->limit && tc->limit->upper == old_limit) { + tc->limit->upper = new_limit; + } + } + + /* optimize in the memlimits case */ + if (type == TOTAL_MEM_LIMIT && + tc->limit != NULL && + tc->limit != old_limit && + tc->limit->parent == tc) { + return tc->limit->cur_size; + } + + if (tc->flags & TALLOC_FLAG_LOOP) { + return 0; + } + + tc->flags |= TALLOC_FLAG_LOOP; + + if (old_limit || new_limit) { + if (old_limit == tc->limit) { + tc->limit = new_limit; + } + } + + switch (type) { + case TOTAL_MEM_SIZE: + if (likely(tc->name != TALLOC_MAGIC_REFERENCE)) { + total = tc->size; + } + break; + case TOTAL_MEM_BLOCKS: + total++; + break; + case TOTAL_MEM_LIMIT: + if (likely(tc->name != TALLOC_MAGIC_REFERENCE)) { + /* + * Don't count memory allocated from a pool + * when calculating limits. Only count the + * pool itself. + */ + if (!(tc->flags & TALLOC_FLAG_POOLMEM)) { + if (tc->flags & TALLOC_FLAG_POOL) { + /* + * If this is a pool, the allocated + * size is in the pool header, and + * remember to add in the prefix + * length. + */ + struct talloc_pool_hdr *pool_hdr + = talloc_pool_from_chunk(tc); + total = pool_hdr->poolsize + + TC_HDR_SIZE + + TP_HDR_SIZE; + } else { + total = tc->size + TC_HDR_SIZE; + } + } + } + break; + } + for (c = tc->child; c; c = c->next) { + total += _talloc_total_mem_internal(TC_PTR_FROM_CHUNK(c), type, + old_limit, new_limit); + } + + tc->flags &= ~TALLOC_FLAG_LOOP; + + return total; +} + +/* + return the total size of a talloc pool (subtree) +*/ +_PUBLIC_ size_t talloc_total_size(const void *ptr) +{ + return _talloc_total_mem_internal(ptr, TOTAL_MEM_SIZE, NULL, NULL); +} + +/* + return the total number of blocks in a talloc pool (subtree) +*/ +_PUBLIC_ size_t talloc_total_blocks(const void *ptr) +{ + return _talloc_total_mem_internal(ptr, TOTAL_MEM_BLOCKS, NULL, NULL); +} + +/* + return the number of external references to a pointer +*/ +_PUBLIC_ size_t talloc_reference_count(const void *ptr) +{ + struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); + struct talloc_reference_handle *h; + size_t ret = 0; + + for (h=tc->refs;h;h=h->next) { + ret++; + } + return ret; +} + +/* + report on memory usage by all children of a pointer, giving a full tree view +*/ +_PUBLIC_ void talloc_report_depth_cb(const void *ptr, int depth, int max_depth, + void (*callback)(const void *ptr, + int depth, int max_depth, + int is_ref, + void *private_data), + void *private_data) +{ + struct talloc_chunk *c, *tc; + + if (ptr == NULL) { + ptr = null_context; + } + if (ptr == NULL) return; + + tc = talloc_chunk_from_ptr(ptr); + + if (tc->flags & TALLOC_FLAG_LOOP) { + return; + } + + callback(ptr, depth, max_depth, 0, private_data); + + if (max_depth >= 0 && depth >= max_depth) { + return; + } + + tc->flags |= TALLOC_FLAG_LOOP; + for (c=tc->child;c;c=c->next) { + if (c->name == TALLOC_MAGIC_REFERENCE) { + struct talloc_reference_handle *h = (struct talloc_reference_handle *)TC_PTR_FROM_CHUNK(c); + callback(h->ptr, depth + 1, max_depth, 1, private_data); + } else { + talloc_report_depth_cb(TC_PTR_FROM_CHUNK(c), depth + 1, max_depth, callback, private_data); + } + } + tc->flags &= ~TALLOC_FLAG_LOOP; +} + +static void talloc_report_depth_FILE_helper(const void *ptr, int depth, int max_depth, int is_ref, void *_f) +{ + const char *name = __talloc_get_name(ptr); + struct talloc_chunk *tc; + FILE *f = (FILE *)_f; + + if (is_ref) { + fprintf(f, "%*sreference to: %s\n", depth*4, "", name); + return; + } + + tc = talloc_chunk_from_ptr(ptr); + if (tc->limit && tc->limit->parent == tc) { + fprintf(f, "%*s%-30s is a memlimit context" + " (max_size = %lu bytes, cur_size = %lu bytes)\n", + depth*4, "", + name, + (unsigned long)tc->limit->max_size, + (unsigned long)tc->limit->cur_size); + } + + if (depth == 0) { + fprintf(f,"%stalloc report on '%s' (total %6lu bytes in %3lu blocks)\n", + (max_depth < 0 ? "full " :""), name, + (unsigned long)talloc_total_size(ptr), + (unsigned long)talloc_total_blocks(ptr)); + return; + } + + fprintf(f, "%*s%-30s contains %6lu bytes in %3lu blocks (ref %d) %p\n", + depth*4, "", + name, + (unsigned long)talloc_total_size(ptr), + (unsigned long)talloc_total_blocks(ptr), + (int)talloc_reference_count(ptr), ptr); + +#if 0 + fprintf(f, "content: "); + if (talloc_total_size(ptr)) { + int tot = talloc_total_size(ptr); + int i; + + for (i = 0; i < tot; i++) { + if ((((char *)ptr)[i] > 31) && (((char *)ptr)[i] < 126)) { + fprintf(f, "%c", ((char *)ptr)[i]); + } else { + fprintf(f, "~%02x", ((char *)ptr)[i]); + } + } + } + fprintf(f, "\n"); +#endif +} + +/* + report on memory usage by all children of a pointer, giving a full tree view +*/ +_PUBLIC_ void talloc_report_depth_file(const void *ptr, int depth, int max_depth, FILE *f) +{ + if (f) { + talloc_report_depth_cb(ptr, depth, max_depth, talloc_report_depth_FILE_helper, f); + fflush(f); + } +} + +/* + report on memory usage by all children of a pointer, giving a full tree view +*/ +_PUBLIC_ void talloc_report_full(const void *ptr, FILE *f) +{ + talloc_report_depth_file(ptr, 0, -1, f); +} + +/* + report on memory usage by all children of a pointer +*/ +_PUBLIC_ void talloc_report(const void *ptr, FILE *f) +{ + talloc_report_depth_file(ptr, 0, 1, f); +} + +/* + enable tracking of the NULL context +*/ +_PUBLIC_ void talloc_enable_null_tracking(void) +{ + if (null_context == NULL) { + null_context = _talloc_named_const(NULL, 0, "null_context"); + if (autofree_context != NULL) { + talloc_reparent(NULL, null_context, autofree_context); + } + } +} + +/* + enable tracking of the NULL context, not moving the autofree context + into the NULL context. This is needed for the talloc testsuite +*/ +_PUBLIC_ void talloc_enable_null_tracking_no_autofree(void) +{ + if (null_context == NULL) { + null_context = _talloc_named_const(NULL, 0, "null_context"); + } +} + +/* + disable tracking of the NULL context +*/ +_PUBLIC_ void talloc_disable_null_tracking(void) +{ + if (null_context != NULL) { + /* we have to move any children onto the real NULL + context */ + struct talloc_chunk *tc, *tc2; + tc = talloc_chunk_from_ptr(null_context); + for (tc2 = tc->child; tc2; tc2=tc2->next) { + if (tc2->parent == tc) tc2->parent = NULL; + if (tc2->prev == tc) tc2->prev = NULL; + } + for (tc2 = tc->next; tc2; tc2=tc2->next) { + if (tc2->parent == tc) tc2->parent = NULL; + if (tc2->prev == tc) tc2->prev = NULL; + } + tc->child = NULL; + tc->next = NULL; + } + talloc_free(null_context); + null_context = NULL; +} + +/* + enable leak reporting on exit +*/ +_PUBLIC_ void talloc_enable_leak_report(void) +{ + talloc_enable_null_tracking(); + talloc_report_null = true; + talloc_setup_atexit(); +} + +/* + enable full leak reporting on exit +*/ +_PUBLIC_ void talloc_enable_leak_report_full(void) +{ + talloc_enable_null_tracking(); + talloc_report_null_full = true; + talloc_setup_atexit(); +} + +/* + talloc and zero memory. +*/ +_PUBLIC_ void *_talloc_zero(const void *ctx, size_t size, const char *name) +{ + void *p = _talloc_named_const(ctx, size, name); + + if (p) { + memset(p, '\0', size); + } + + return p; +} + +/* + memdup with a talloc. +*/ +_PUBLIC_ void *_talloc_memdup(const void *t, const void *p, size_t size, const char *name) +{ + void *newp = NULL; + + if (likely(size > 0) && unlikely(p == NULL)) { + return NULL; + } + + newp = _talloc_named_const(t, size, name); + if (likely(newp != NULL) && likely(size > 0)) { + memcpy(newp, p, size); + } + + return newp; +} + +static inline char *__talloc_strlendup(const void *t, const char *p, size_t len) +{ + char *ret; + struct talloc_chunk *tc = NULL; + + ret = (char *)__talloc(t, len + 1, &tc); + if (unlikely(!ret)) return NULL; + + memcpy(ret, p, len); + ret[len] = 0; + + _tc_set_name_const(tc, ret); + return ret; +} + +/* + strdup with a talloc +*/ +_PUBLIC_ char *talloc_strdup(const void *t, const char *p) +{ + if (unlikely(!p)) return NULL; + return __talloc_strlendup(t, p, strlen(p)); +} + +/* + strndup with a talloc +*/ +_PUBLIC_ char *talloc_strndup(const void *t, const char *p, size_t n) +{ + if (unlikely(!p)) return NULL; + return __talloc_strlendup(t, p, strnlen(p, n)); +} + +static inline char *__talloc_strlendup_append(char *s, size_t slen, + const char *a, size_t alen) +{ + char *ret; + + ret = talloc_realloc(NULL, s, char, slen + alen + 1); + if (unlikely(!ret)) return NULL; + + /* append the string and the trailing \0 */ + memcpy(&ret[slen], a, alen); + ret[slen+alen] = 0; + + _tc_set_name_const(talloc_chunk_from_ptr(ret), ret); + return ret; +} + +/* + * Appends at the end of the string. + */ +_PUBLIC_ char *talloc_strdup_append(char *s, const char *a) +{ + if (unlikely(!s)) { + return talloc_strdup(NULL, a); + } + + if (unlikely(!a)) { + return s; + } + + return __talloc_strlendup_append(s, strlen(s), a, strlen(a)); +} + +/* + * Appends at the end of the talloc'ed buffer, + * not the end of the string. + */ +_PUBLIC_ char *talloc_strdup_append_buffer(char *s, const char *a) +{ + size_t slen; + + if (unlikely(!s)) { + return talloc_strdup(NULL, a); + } + + if (unlikely(!a)) { + return s; + } + + slen = talloc_get_size(s); + if (likely(slen > 0)) { + slen--; + } + + return __talloc_strlendup_append(s, slen, a, strlen(a)); +} + +/* + * Appends at the end of the string. + */ +_PUBLIC_ char *talloc_strndup_append(char *s, const char *a, size_t n) +{ + if (unlikely(!s)) { + return talloc_strndup(NULL, a, n); + } + + if (unlikely(!a)) { + return s; + } + + return __talloc_strlendup_append(s, strlen(s), a, strnlen(a, n)); +} + +/* + * Appends at the end of the talloc'ed buffer, + * not the end of the string. + */ +_PUBLIC_ char *talloc_strndup_append_buffer(char *s, const char *a, size_t n) +{ + size_t slen; + + if (unlikely(!s)) { + return talloc_strndup(NULL, a, n); + } + + if (unlikely(!a)) { + return s; + } + + slen = talloc_get_size(s); + if (likely(slen > 0)) { + slen--; + } + + return __talloc_strlendup_append(s, slen, a, strnlen(a, n)); +} + +#ifndef HAVE_VA_COPY +#ifdef HAVE___VA_COPY +#define va_copy(dest, src) __va_copy(dest, src) +#else +#define va_copy(dest, src) (dest) = (src) +#endif +#endif + +static struct talloc_chunk *_vasprintf_tc(const void *t, + const char *fmt, + va_list ap) PRINTF_ATTRIBUTE(2,0); + +static struct talloc_chunk *_vasprintf_tc(const void *t, + const char *fmt, + va_list ap) +{ + int vlen; + size_t len; + char *ret; + va_list ap2; + struct talloc_chunk *tc = NULL; + char buf[1024]; + + va_copy(ap2, ap); + vlen = vsnprintf(buf, sizeof(buf), fmt, ap2); + va_end(ap2); + if (unlikely(vlen < 0)) { + return NULL; + } + len = vlen; + if (unlikely(len + 1 < len)) { + return NULL; + } + + ret = (char *)__talloc(t, len+1, &tc); + if (unlikely(!ret)) return NULL; + + if (len < sizeof(buf)) { + memcpy(ret, buf, len+1); + } else { + va_copy(ap2, ap); + vsnprintf(ret, len+1, fmt, ap2); + va_end(ap2); + } + + _tc_set_name_const(tc, ret); + return tc; +} + +_PUBLIC_ char *talloc_vasprintf(const void *t, const char *fmt, va_list ap) +{ + struct talloc_chunk *tc = _vasprintf_tc(t, fmt, ap); + if (tc == NULL) { + return NULL; + } + return TC_PTR_FROM_CHUNK(tc); +} + + +/* + Perform string formatting, and return a pointer to newly allocated + memory holding the result, inside a memory pool. + */ +_PUBLIC_ char *talloc_asprintf(const void *t, const char *fmt, ...) +{ + va_list ap; + char *ret; + + va_start(ap, fmt); + ret = talloc_vasprintf(t, fmt, ap); + va_end(ap); + return ret; +} + +static inline char *__talloc_vaslenprintf_append(char *s, size_t slen, + const char *fmt, va_list ap) + PRINTF_ATTRIBUTE(3,0); + +static inline char *__talloc_vaslenprintf_append(char *s, size_t slen, + const char *fmt, va_list ap) +{ + ssize_t alen; + va_list ap2; + char c; + + va_copy(ap2, ap); + /* this call looks strange, but it makes it work on older solaris boxes */ + alen = vsnprintf(&c, 1, fmt, ap2); + va_end(ap2); + + if (alen <= 0) { + /* Either the vsnprintf failed or the format resulted in + * no characters being formatted. In the former case, we + * ought to return NULL, in the latter we ought to return + * the original string. Most current callers of this + * function expect it to never return NULL. + */ + return s; + } + + s = talloc_realloc(NULL, s, char, slen + alen + 1); + if (!s) return NULL; + + vsnprintf(s + slen, alen + 1, fmt, ap); + + _tc_set_name_const(talloc_chunk_from_ptr(s), s); + return s; +} + +/** + * Realloc @p s to append the formatted result of @p fmt and @p ap, + * and return @p s, which may have moved. Good for gradually + * accumulating output into a string buffer. Appends at the end + * of the string. + **/ +_PUBLIC_ char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap) +{ + if (unlikely(!s)) { + return talloc_vasprintf(NULL, fmt, ap); + } + + return __talloc_vaslenprintf_append(s, strlen(s), fmt, ap); +} + +/** + * Realloc @p s to append the formatted result of @p fmt and @p ap, + * and return @p s, which may have moved. Always appends at the + * end of the talloc'ed buffer, not the end of the string. + **/ +_PUBLIC_ char *talloc_vasprintf_append_buffer(char *s, const char *fmt, va_list ap) +{ + size_t slen; + + if (unlikely(!s)) { + return talloc_vasprintf(NULL, fmt, ap); + } + + slen = talloc_get_size(s); + if (likely(slen > 0)) { + slen--; + } + + return __talloc_vaslenprintf_append(s, slen, fmt, ap); +} + +/* + Realloc @p s to append the formatted result of @p fmt and return @p + s, which may have moved. Good for gradually accumulating output + into a string buffer. + */ +_PUBLIC_ char *talloc_asprintf_append(char *s, const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + s = talloc_vasprintf_append(s, fmt, ap); + va_end(ap); + return s; +} + +/* + Realloc @p s to append the formatted result of @p fmt and return @p + s, which may have moved. Good for gradually accumulating output + into a buffer. + */ +_PUBLIC_ char *talloc_asprintf_append_buffer(char *s, const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + s = talloc_vasprintf_append_buffer(s, fmt, ap); + va_end(ap); + return s; +} + +_PUBLIC_ void talloc_asprintf_addbuf(char **ps, const char *fmt, ...) +{ + va_list ap; + char *s = *ps; + char *t = NULL; + + if (s == NULL) { + return; + } + + va_start(ap, fmt); + t = talloc_vasprintf_append_buffer(s, fmt, ap); + va_end(ap); + + if (t == NULL) { + /* signal failure to the next caller */ + TALLOC_FREE(s); + *ps = NULL; + } else { + *ps = t; + } +} + +/* + alloc an array, checking for integer overflow in the array size +*/ +_PUBLIC_ void *_talloc_array(const void *ctx, size_t el_size, unsigned count, const char *name) +{ + if (count >= MAX_TALLOC_SIZE/el_size) { + return NULL; + } + return _talloc_named_const(ctx, el_size * count, name); +} + +/* + alloc an zero array, checking for integer overflow in the array size +*/ +_PUBLIC_ void *_talloc_zero_array(const void *ctx, size_t el_size, unsigned count, const char *name) +{ + if (count >= MAX_TALLOC_SIZE/el_size) { + return NULL; + } + return _talloc_zero(ctx, el_size * count, name); +} + +/* + realloc an array, checking for integer overflow in the array size +*/ +_PUBLIC_ void *_talloc_realloc_array(const void *ctx, void *ptr, size_t el_size, unsigned count, const char *name) +{ + if (count >= MAX_TALLOC_SIZE/el_size) { + return NULL; + } + return _talloc_realloc(ctx, ptr, el_size * count, name); +} + +/* + a function version of talloc_realloc(), so it can be passed as a function pointer + to libraries that want a realloc function (a realloc function encapsulates + all the basic capabilities of an allocation library, which is why this is useful) +*/ +_PUBLIC_ void *talloc_realloc_fn(const void *context, void *ptr, size_t size) +{ + return _talloc_realloc(context, ptr, size, NULL); +} + + +static int talloc_autofree_destructor(void *ptr) +{ + autofree_context = NULL; + return 0; +} + +/* + return a context which will be auto-freed on exit + this is useful for reducing the noise in leak reports +*/ +_PUBLIC_ void *talloc_autofree_context(void) +{ + if (autofree_context == NULL) { + autofree_context = _talloc_named_const(NULL, 0, "autofree_context"); + talloc_set_destructor(autofree_context, talloc_autofree_destructor); + talloc_setup_atexit(); + } + return autofree_context; +} + +_PUBLIC_ size_t talloc_get_size(const void *context) +{ + struct talloc_chunk *tc; + + if (context == NULL) { + return 0; + } + + tc = talloc_chunk_from_ptr(context); + + return tc->size; +} + +/* + find a parent of this context that has the given name, if any +*/ +_PUBLIC_ void *talloc_find_parent_byname(const void *context, const char *name) +{ + struct talloc_chunk *tc; + + if (context == NULL) { + return NULL; + } + + tc = talloc_chunk_from_ptr(context); + while (tc) { + if (tc->name && strcmp(tc->name, name) == 0) { + return TC_PTR_FROM_CHUNK(tc); + } + while (tc && tc->prev) tc = tc->prev; + if (tc) { + tc = tc->parent; + } + } + return NULL; +} + +/* + show the parentage of a context +*/ +_PUBLIC_ void talloc_show_parents(const void *context, FILE *file) +{ + struct talloc_chunk *tc; + + if (context == NULL) { + fprintf(file, "talloc no parents for NULL\n"); + return; + } + + tc = talloc_chunk_from_ptr(context); + fprintf(file, "talloc parents of '%s'\n", __talloc_get_name(context)); + while (tc) { + fprintf(file, "\t'%s'\n", __talloc_get_name(TC_PTR_FROM_CHUNK(tc))); + while (tc && tc->prev) tc = tc->prev; + if (tc) { + tc = tc->parent; + } + } + fflush(file); +} + +/* + return 1 if ptr is a parent of context +*/ +static int _talloc_is_parent(const void *context, const void *ptr, int depth) +{ + struct talloc_chunk *tc; + + if (context == NULL) { + return 0; + } + + tc = talloc_chunk_from_ptr(context); + while (tc) { + if (depth <= 0) { + return 0; + } + if (TC_PTR_FROM_CHUNK(tc) == ptr) return 1; + while (tc && tc->prev) tc = tc->prev; + if (tc) { + tc = tc->parent; + depth--; + } + } + return 0; +} + +/* + return 1 if ptr is a parent of context +*/ +_PUBLIC_ int talloc_is_parent(const void *context, const void *ptr) +{ + return _talloc_is_parent(context, ptr, TALLOC_MAX_DEPTH); +} + +/* + return the total size of memory used by this context and all children +*/ +static inline size_t _talloc_total_limit_size(const void *ptr, + struct talloc_memlimit *old_limit, + struct talloc_memlimit *new_limit) +{ + return _talloc_total_mem_internal(ptr, TOTAL_MEM_LIMIT, + old_limit, new_limit); +} + +static inline bool talloc_memlimit_check(struct talloc_memlimit *limit, size_t size) +{ + struct talloc_memlimit *l; + + for (l = limit; l != NULL; l = l->upper) { + if (l->max_size != 0 && + ((l->max_size <= l->cur_size) || + (l->max_size - l->cur_size < size))) { + return false; + } + } + + return true; +} + +/* + Update memory limits when freeing a talloc_chunk. +*/ +static void tc_memlimit_update_on_free(struct talloc_chunk *tc) +{ + size_t limit_shrink_size; + + if (!tc->limit) { + return; + } + + /* + * Pool entries don't count. Only the pools + * themselves are counted as part of the memory + * limits. Note that this also takes care of + * nested pools which have both flags + * TALLOC_FLAG_POOLMEM|TALLOC_FLAG_POOL set. + */ + if (tc->flags & TALLOC_FLAG_POOLMEM) { + return; + } + + /* + * If we are part of a memory limited context hierarchy + * we need to subtract the memory used from the counters + */ + + limit_shrink_size = tc->size+TC_HDR_SIZE; + + /* + * If we're deallocating a pool, take into + * account the prefix size added for the pool. + */ + + if (tc->flags & TALLOC_FLAG_POOL) { + limit_shrink_size += TP_HDR_SIZE; + } + + talloc_memlimit_shrink(tc->limit, limit_shrink_size); + + if (tc->limit->parent == tc) { + free(tc->limit); + } + + tc->limit = NULL; +} + +/* + Increase memory limit accounting after a malloc/realloc. +*/ +static void talloc_memlimit_grow(struct talloc_memlimit *limit, + size_t size) +{ + struct talloc_memlimit *l; + + for (l = limit; l != NULL; l = l->upper) { + size_t new_cur_size = l->cur_size + size; + if (new_cur_size < l->cur_size) { + talloc_abort("logic error in talloc_memlimit_grow\n"); + return; + } + l->cur_size = new_cur_size; + } +} + +/* + Decrease memory limit accounting after a free/realloc. +*/ +static void talloc_memlimit_shrink(struct talloc_memlimit *limit, + size_t size) +{ + struct talloc_memlimit *l; + + for (l = limit; l != NULL; l = l->upper) { + if (l->cur_size < size) { + talloc_abort("logic error in talloc_memlimit_shrink\n"); + return; + } + l->cur_size = l->cur_size - size; + } +} + +_PUBLIC_ int talloc_set_memlimit(const void *ctx, size_t max_size) +{ + struct talloc_chunk *tc = talloc_chunk_from_ptr(ctx); + struct talloc_memlimit *orig_limit; + struct talloc_memlimit *limit = NULL; + + if (tc->limit && tc->limit->parent == tc) { + tc->limit->max_size = max_size; + return 0; + } + orig_limit = tc->limit; + + limit = malloc(sizeof(struct talloc_memlimit)); + if (limit == NULL) { + return 1; + } + limit->parent = tc; + limit->max_size = max_size; + limit->cur_size = _talloc_total_limit_size(ctx, tc->limit, limit); + + if (orig_limit) { + limit->upper = orig_limit; + } else { + limit->upper = NULL; + } + + return 0; +} |