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Diffstat (limited to 'lib/talloc/talloc.c')
-rw-r--r-- | lib/talloc/talloc.c | 1130 |
1 files changed, 1130 insertions, 0 deletions
diff --git a/lib/talloc/talloc.c b/lib/talloc/talloc.c new file mode 100644 index 0000000..c660870 --- /dev/null +++ b/lib/talloc/talloc.c @@ -0,0 +1,1130 @@ +/* + 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 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +/* + inspired by http://swapped.cc/halloc/ +*/ + + +#include "config.h" + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +/* nfsim additions */ +#define HAVE_SYS_TYPES_H +#define HAVE_UNISTD_H +#define HAVE_STDARG_H +#define HAVE_STDINT_H +#define HAVE_VA_COPY + +#ifdef HAVE_SYS_TYPES_H +#include <sys/types.h> +#endif + +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif + +#ifdef HAVE_STDARG_H +#include <stdarg.h> +#else +#include <varargs.h> +#endif + +#ifdef HAVE_STDINT_H +#include <stdint.h> +#endif + +#include "talloc.h" + +/* use this to force every realloc to change the pointer, to stress test + code that might not cope */ +#define ALWAYS_REALLOC 0 + + +#define MAX_TALLOC_SIZE 0x10000000 +#define TALLOC_MAGIC 0xe814ec4f +#define TALLOC_MAGIC_FREE 0x7faebef3 +#define TALLOC_MAGIC_REFERENCE ((const char *)1) + +/* 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 + +/* this null_context is only used if talloc_enable_leak_report() or + talloc_enable_leak_report_full() is called, otherwise it remains + NULL +*/ +static const void *null_context; +static void *cleanup_context; + + +struct talloc_reference_handle { + struct talloc_reference_handle *next, *prev; + void *ptr; +}; + +typedef int (*talloc_destructor_t)(void *); + +struct talloc_chunk { + struct talloc_chunk *next, *prev; + struct talloc_chunk *parent, *child; + struct talloc_reference_handle *refs; + size_t size; + talloc_destructor_t destructor; + const char *name; + union { + unsigned magic; + double align_dummy; + } u; +}; + +/* panic if we get a bad magic value */ +static struct talloc_chunk *talloc_chunk_from_ptr(const void *ptr) +{ + struct talloc_chunk *tc = discard_const_p(struct talloc_chunk, ptr)-1; + if (tc->u.magic != TALLOC_MAGIC) { + if (tc->u.magic == TALLOC_MAGIC_FREE) { + TALLOC_ABORT("Bad talloc magic value - double free"); + } else { + TALLOC_ABORT("Bad talloc magic value - unknown value"); + } + } + + 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 struct talloc_chunk *talloc_parent_chunk(const void *ptr) +{ + struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); + while (tc->prev) tc=tc->prev; + return tc->parent; +} + +void *talloc_parent(const void *ptr) +{ + struct talloc_chunk *tc = talloc_parent_chunk(ptr); + return (void *)(tc+1); +} + +/* + Allocate a bit of memory as a child of an existing pointer +*/ +void *_talloc(const void *context, size_t size) +{ + struct talloc_chunk *tc; + + if (context == NULL) { + context = null_context; + } + + if (size >= MAX_TALLOC_SIZE) { + return NULL; + } + + tc = malloc(sizeof(*tc)+size); + if (tc == NULL) return NULL; + + tc->size = size; + tc->u.magic = TALLOC_MAGIC; + tc->destructor = NULL; + tc->child = NULL; + tc->name = NULL; + tc->refs = NULL; + + if (context) { + struct talloc_chunk *parent = talloc_chunk_from_ptr(context); + + tc->parent = parent; + + if (parent->child) { + parent->child->parent = NULL; + } + + _TLIST_ADD(parent->child, tc); + } else { + tc->next = tc->prev = tc->parent = NULL; + } + + return (void *)(tc+1); +} + + +/* + 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 +*/ +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. +*/ +void talloc_increase_ref_count(const void *ptr) +{ + talloc_reference(null_context, ptr); +} + +/* + helper for talloc_reference() +*/ +static int talloc_reference_destructor(void *ptr) +{ + struct talloc_reference_handle *handle = ptr; + struct talloc_chunk *tc1 = talloc_chunk_from_ptr(ptr); + struct talloc_chunk *tc2 = talloc_chunk_from_ptr(handle->ptr); + if (tc1->destructor != (talloc_destructor_t)-1) { + tc1->destructor = NULL; + } + _TLIST_REMOVE(tc2->refs, handle); + talloc_free(handle); + return 0; +} + +/* + 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 +*/ +void *talloc_reference(const void *context, const void *ptr) +{ + struct talloc_chunk *tc; + struct talloc_reference_handle *handle; + if (ptr == NULL) return NULL; + + tc = talloc_chunk_from_ptr(ptr); + handle = talloc_named_const(context, sizeof(*handle), + TALLOC_MAGIC_REFERENCE); + + if (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); + _TLIST_ADD(tc->refs, handle); + return handle->ptr; +} + +/* + 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 int talloc_unreference(const void *context, const void *ptr) +{ + struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); + struct talloc_reference_handle *h; + + if (context == NULL) { + context = null_context; + } + + for (h=tc->refs;h;h=h->next) { + struct talloc_chunk *p = talloc_parent_chunk(h); + if ((p==NULL && context==NULL) || p+1 == context) break; + } + if (h == NULL) { + return -1; + } + + talloc_set_destructor(h, NULL); + _TLIST_REMOVE(tc->refs, h); + talloc_free(h); + return 0; +} + +/* + remove a specific parent context from a pointer. This is a more + controlled varient of talloc_free() +*/ +int talloc_unlink(const void *context, void *ptr) +{ + struct talloc_chunk *tc_p, *new_p; + 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) { + if (talloc_parent_chunk(ptr) != NULL) { + return -1; + } + } else { + if (talloc_chunk_from_ptr(context) + != talloc_parent_chunk(ptr)) { + return -1; + } + } + + tc_p = talloc_chunk_from_ptr(ptr); + + if (tc_p->refs == NULL) { + return talloc_free(ptr); + } + + new_p = talloc_parent_chunk(tc_p->refs); + if (new_p) { + new_parent = new_p+1; + } else { + new_parent = NULL; + } + + if (talloc_unreference(new_parent, ptr) != 0) { + return -1; + } + + talloc_steal(new_parent, ptr); + + return 0; +} + +/* + add a name to an existing pointer - va_list version +*/ +static void talloc_set_name_v(const void *ptr, const char *fmt, va_list ap) + PRINTF_ATTRIBUTE(2,0); + +static void talloc_set_name_v(const void *ptr, const char *fmt, va_list ap) +{ + struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); + tc->name = talloc_vasprintf(ptr, fmt, ap); + if (tc->name) { + talloc_set_name_const(tc->name, ".name"); + } +} + +/* + add a name to an existing pointer +*/ +void talloc_set_name(const void *ptr, const char *fmt, ...) +{ + va_list ap; + va_start(ap, fmt); + talloc_set_name_v(ptr, fmt, ap); + va_end(ap); +} + +/* + more efficient way to add a name to a pointer - the name must point to a + true string constant +*/ +void talloc_set_name_const(const void *ptr, const char *name) +{ + struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); + tc->name = 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. +*/ +void *talloc_named(const void *context, size_t size, const char *fmt, ...) +{ + va_list ap; + void *ptr; + + ptr = _talloc(context, size); + if (ptr == NULL) return NULL; + + va_start(ap, fmt); + talloc_set_name_v(ptr, fmt, ap); + va_end(ap); + + return ptr; +} + +/* + 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. +*/ +void *talloc_named_const(const void *context, size_t size, const char *name) +{ + void *ptr; + + ptr = _talloc(context, size); + if (ptr == NULL) { + return NULL; + } + + talloc_set_name_const(ptr, name); + + return ptr; +} + +/* + return the name of a talloc ptr, or "UNNAMED" +*/ +const char *talloc_get_name(const void *ptr) +{ + struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); + if (tc->name == TALLOC_MAGIC_REFERENCE) { + return ".reference"; + } + if (tc->name) { + return tc->name; + } + return "UNNAMED"; +} + + +/* + check if a pointer has the given name. If it does, return the pointer, + otherwise return NULL +*/ +void *talloc_check_name(const void *ptr, const char *name) +{ + const char *pname; + if (ptr == NULL) return NULL; + pname = talloc_get_name(ptr); + if (pname == name || strcmp(pname, name) == 0) { + return discard_const_p(void, ptr); + } + return NULL; +} + + +/* + this is for compatibility with older versions of talloc +*/ +void *talloc_init(const char *fmt, ...) +{ + va_list ap; + void *ptr; + + ptr = _talloc(NULL, 0); + if (ptr == NULL) return NULL; + + va_start(ap, fmt); + talloc_set_name_v(ptr, fmt, ap); + va_end(ap); + + return ptr; +} + +/* + 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. +*/ +static void talloc_free_children(void *ptr) +{ + struct talloc_chunk *tc; + + if (ptr == NULL) { + return; + } + + tc = talloc_chunk_from_ptr(ptr); + + 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->child+1; + const void *new_parent = null_context; + if (tc->child->refs) { + struct talloc_chunk *p = + talloc_parent_chunk(tc->child->refs); + if (p) new_parent = p+1; + } + if (talloc_free(child) == -1) { + if (new_parent == null_context) { + struct talloc_chunk *p = + talloc_parent_chunk(ptr); + if (p) new_parent = p+1; + } + talloc_steal(new_parent, child); + } + } +} + +/* + 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 +*/ +int talloc_free(void *ptr) +{ + struct talloc_chunk *tc; + + if (ptr == NULL) { + return -1; + } + + tc = talloc_chunk_from_ptr(ptr); + + if (tc->refs) { + talloc_reference_destructor(tc->refs); + return -1; + } + + if (tc->destructor) { + talloc_destructor_t d = tc->destructor; + if (d == (talloc_destructor_t)-1) { + return -1; + } + tc->destructor = (talloc_destructor_t)-1; + if (d(ptr) == -1) { + tc->destructor = d; + return -1; + } + tc->destructor = NULL; + } + + talloc_free_children(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->u.magic = TALLOC_MAGIC_FREE; + + free(tc); + return 0; +} + + + +/* + A talloc version of realloc. The context argument is only used if + ptr is NULL +*/ +void *_talloc_realloc(const void *context, void *ptr, size_t size, + const char *name) +{ + struct talloc_chunk *tc; + void *new_ptr; + + /* size zero is equivalent to free() */ + if (size == 0) { + talloc_free(ptr); + return NULL; + } + + if (size >= MAX_TALLOC_SIZE) { + return NULL; + } + + /* realloc(NULL) is equavalent 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 (tc->refs) { + return NULL; + } + + /* by resetting magic we catch users of the old memory */ + tc->u.magic = TALLOC_MAGIC_FREE; + +#if ALWAYS_REALLOC + new_ptr = malloc(size + sizeof(*tc)); + if (new_ptr) { + memcpy(new_ptr, tc, tc->size + sizeof(*tc)); + free(tc); + } +#else + new_ptr = realloc(tc, size + sizeof(*tc)); +#endif + if (!new_ptr) { + tc->u.magic = TALLOC_MAGIC; + return NULL; + } + + tc = new_ptr; + tc->u.magic = TALLOC_MAGIC; + if (tc->parent) { + tc->parent->child = new_ptr; + } + if (tc->child) { + tc->child->parent = new_ptr; + } + + if (tc->prev) { + tc->prev->next = tc; + } + if (tc->next) { + tc->next->prev = tc; + } + + tc->size = size; + talloc_set_name_const(tc+1, name); + + return (void *)(tc+1); +} + +/* + move a lump of memory from one talloc context to another return the + ptr on success, or NULL if it could not be transferred. + passing NULL as ptr will always return NULL with no side effects. +*/ +void *talloc_steal(const void *new_ctx, const void *ptr) +{ + struct talloc_chunk *tc, *new_tc; + + if (!ptr) { + return NULL; + } + + if (new_ctx == NULL) { + new_ctx = null_context; + } + + tc = talloc_chunk_from_ptr(ptr); + + if (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 (tc == 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->parent = new_tc; + if (new_tc->child) new_tc->child->parent = NULL; + _TLIST_ADD(new_tc->child, tc); + + return discard_const_p(void, ptr); +} + +/* + return the total size of a talloc pool (subtree) +*/ +off_t talloc_total_size(const void *ptr) +{ + off_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); + + total = tc->size; + for (c=tc->child;c;c=c->next) { + total += talloc_total_size(c+1); + } + return total; +} + +/* + return the total number of blocks in a talloc pool (subtree) +*/ +off_t talloc_total_blocks(const void *ptr) +{ + off_t total = 0; + struct talloc_chunk *c, *tc = talloc_chunk_from_ptr(ptr); + + total++; + for (c=tc->child;c;c=c->next) { + total += talloc_total_blocks(c+1); + } + return total; +} + +/* + return the number of external references to a pointer +*/ +static int talloc_reference_count(const void *ptr) +{ + struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); + struct talloc_reference_handle *h; + int 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 +*/ +void talloc_report_depth(const void *ptr, FILE *f, int depth) +{ + struct talloc_chunk *c, *tc = talloc_chunk_from_ptr(ptr); + + for (c=tc->child;c;c=c->next) { + if (c->name == TALLOC_MAGIC_REFERENCE) { + struct talloc_reference_handle *handle = (void *)(c+1); + const char *name2 = talloc_get_name(handle->ptr); + fprintf(f, "%*sreference to: %s\n", depth*4, "", name2); + } else { + const char *name = talloc_get_name(c+1); + fprintf(f, "%*s%-30s contains %6lu bytes " + "in %3lu blocks (ref %d)\n", + depth * 4, "", name, + (unsigned long)talloc_total_size(c+1), + (unsigned long)talloc_total_blocks(c+1), + talloc_reference_count(c+1)); + talloc_report_depth(c+1, f, depth+1); + } + } + +} + +/* + report on memory usage by all children of a pointer, giving a full tree view +*/ +void talloc_report_full(const void *ptr, FILE *f) +{ + if (ptr == NULL) { + ptr = null_context; + } + if (ptr == NULL) return; + + fprintf(f, "full talloc report on '%s' " + "(total %lu bytes in %lu blocks)\n", + talloc_get_name(ptr), + (unsigned long)talloc_total_size(ptr), + (unsigned long)talloc_total_blocks(ptr)); + + talloc_report_depth(ptr, f, 1); + fflush(f); +} + +/* + report on memory usage by all children of a pointer +*/ +void talloc_report(const void *ptr, FILE *f) +{ + struct talloc_chunk *c, *tc; + + if (ptr == NULL) { + ptr = null_context; + } + if (ptr == NULL) return; + + fprintf(f, "talloc report on '%s' (total %lu bytes in %lu blocks)\n", + talloc_get_name(ptr), + (unsigned long)talloc_total_size(ptr), + (unsigned long)talloc_total_blocks(ptr)); + + tc = talloc_chunk_from_ptr(ptr); + + for (c=tc->child;c;c=c->next) { + fprintf(f, "\t%-30s contains %6lu bytes in %3lu blocks\n", + talloc_get_name(c+1), + (unsigned long)talloc_total_size(c+1), + (unsigned long)talloc_total_blocks(c+1)); + } + fflush(f); +} + +/* + report on any memory hanging off the null context +*/ +static void talloc_report_null(void) +{ + if (talloc_total_size(null_context) != 0) { + talloc_report(null_context, stderr); + } +} + +/* + report on any memory hanging off the null context +*/ +static void talloc_report_null_full(void) +{ + if (talloc_total_size(null_context) != 0) { + talloc_report_full(null_context, stderr); + } +} + +/* + enable tracking of the NULL context +*/ +void talloc_enable_null_tracking(void) +{ + if (null_context == NULL) { + null_context = talloc_named_const(NULL, 0, "null_context"); + } +} + +/* + enable leak reporting on exit +*/ +void talloc_enable_leak_report(void) +{ + talloc_enable_null_tracking(); + atexit(talloc_report_null); +} + +/* + enable full leak reporting on exit +*/ +void talloc_enable_leak_report_full(void) +{ + talloc_enable_null_tracking(); + atexit(talloc_report_null_full); +} + +/* + talloc and zero memory. +*/ +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. +*/ +void *_talloc_memdup(const void *t, const void *p, size_t size, const char *name) +{ + void *newp = talloc_named_const(t, size, name); + + if (newp) { + memcpy(newp, p, size); + } + + return newp; +} + +/* + strdup with a talloc +*/ +char *talloc_strdup(const void *t, const char *p) +{ + char *ret; + if (!p) { + return NULL; + } + ret = talloc_memdup(t, p, strlen(p) + 1); + if (ret) { + talloc_set_name_const(ret, ret); + } + return ret; +} + +/* + strndup with a talloc +*/ +char *talloc_strndup(const void *t, const char *p, size_t n) +{ + size_t len; + char *ret; + + for (len=0; len<n && p[len]; len++) ; + + ret = _talloc(t, len + 1); + if (!ret) { return NULL; } + memcpy(ret, p, len); + ret[len] = 0; + talloc_set_name_const(ret, ret); + return ret; +} + +#ifndef VA_COPY +#ifdef HAVE_VA_COPY +#define VA_COPY(dest, src) va_copy(dest, src) +#elif defined(HAVE___VA_COPY) +#define VA_COPY(dest, src) __va_copy(dest, src) +#else +#define VA_COPY(dest, src) (dest) = (src) +#endif +#endif + +char *talloc_vasprintf(const void *t, const char *fmt, va_list ap) +{ + int len; + char *ret; + va_list ap2; + + VA_COPY(ap2, ap); + + len = vsnprintf(NULL, 0, fmt, ap2); + + ret = _talloc(t, len+1); + if (ret) { + VA_COPY(ap2, ap); + vsnprintf(ret, len+1, fmt, ap2); + talloc_set_name_const(ret, ret); + } + + return ret; +} + + +/* + Perform string formatting, and return a pointer to newly allocated + memory holding the result, inside a memory pool. + */ +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; +} + + +/** + * 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. + **/ + +static char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap) + PRINTF_ATTRIBUTE(2,0); + +static char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap) +{ + struct talloc_chunk *tc; + int len, s_len; + va_list ap2; + + if (s == NULL) { + return talloc_vasprintf(NULL, fmt, ap); + } + + tc = talloc_chunk_from_ptr(s); + + VA_COPY(ap2, ap); + + s_len = tc->size - 1; + len = vsnprintf(NULL, 0, fmt, ap2); + + s = talloc_realloc(NULL, s, char, s_len + len+1); + if (!s) return NULL; + + VA_COPY(ap2, ap); + + vsnprintf(s+s_len, len+1, fmt, ap2); + talloc_set_name_const(s, s); + + 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 string buffer. + */ +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; +} + +/* + alloc an array, checking for integer overflow in the array size +*/ +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 +*/ +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 +*/ +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) +*/ +void *talloc_realloc_fn(const void *context, void *ptr, size_t size) +{ + return _talloc_realloc(context, ptr, size, NULL); +} + + +static void talloc_autofree(void) +{ + talloc_free(cleanup_context); + cleanup_context = NULL; +} + +/* + return a context which will be auto-freed on exit + this is useful for reducing the noise in leak reports +*/ +void *talloc_autofree_context(void) +{ + if (cleanup_context == NULL) { + cleanup_context = talloc_named_const(NULL, 0, + "autofree_context"); + atexit(talloc_autofree); + } + return cleanup_context; +} + +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; +} |