tal: take implies NULL passthrough.

[ccan] / ccan / tal / tal.c

diff --git a/ccan/tal/tal.c b/ccan/tal/tal.c
index ffe2d71334dce4473d57243bca0827aaa5fee565..dce9d233a076733f636f42fbc2e02f0956cd364a 100644 (file)
--- a/ccan/tal/tal.c
+++ b/ccan/tal/tal.c
@@ -3,6 +3,7 @@
 #include <ccan/compiler/compiler.h>
 #include <ccan/hash/hash.h>
 #include <ccan/list/list.h>
+#include <ccan/take/take.h>
 #include <assert.h>
 #include <stdio.h>
 #include <stdarg.h>
@@ -103,12 +104,14 @@ static struct group *next_group(struct group *group)
        return list_entry(group->list.n.next, struct group, list.n);
 }
 
-static bool atexit_set = false;
+static bool initialized = false;
+
 /* This means valgrind can see leaks. */
-static void unlink_null(void)
+static void tal_cleanup(void)
 {
        struct group *i, *next;
 
+       /* Unlink null_parent. */
        for (i = next_group(&null_parent.c.group);
             i != &null_parent.c.group;
             i = next) {
@@ -116,6 +119,15 @@ static void unlink_null(void)
                freefn(i);
        }
        null_parent.c.group.first_child = NULL;
+
+       /* Cleanup any taken pointers. */
+       take_cleanup();
+}
+
+/* For allocation failures inside ccan/take */
+static void take_alloc_failed(const void *p)
+{
+       tal_free(p);
 }
 
 #ifndef NDEBUG
@@ -332,9 +344,10 @@ static bool add_child(struct tal_hdr *parent, struct tal_hdr *child)
        if (unlikely(!group->first_child)) {
                assert(group == &children->group);
                /* This hits on first child appended to null parent. */
-               if (unlikely(!atexit_set)) {
-                       atexit(unlink_null);
-                       atexit_set = true;
+               if (unlikely(!initialized)) {
+                       atexit(tal_cleanup);
+                       take_allocfail(take_alloc_failed);
+                       initialized = true;
                }
                /* Link group into this child, make it the first one. */
                group->hdr.next = child->prop;
@@ -665,6 +678,12 @@ bool tal_resize_(tal_t **ctxp, size_t size)
 
         old_t = debug_tal(to_tal_hdr(*ctxp));
 
+       /* Don't hand silly sizes to realloc. */
+       if (size >> (CHAR_BIT*sizeof(size) - 1)) {
+               call_error("Reallocation size overflow");
+               return false;
+       }
+
         t = resizefn(old_t, size + sizeof(struct tal_hdr));
        if (!t) {
                call_error("Reallocation failure");
@@ -699,29 +718,56 @@ bool tal_resize_(tal_t **ctxp, size_t size)
 
 char *tal_strdup(const tal_t *ctx, const char *p)
 {
-       return tal_memdup(ctx, p, strlen(p)+1);
+       /* We have to let through NULL for take(). */
+       return tal_dup(ctx, char, p, p ? strlen(p) + 1: 1, 0);
 }
 
 char *tal_strndup(const tal_t *ctx, const char *p, size_t n)
 {
+       size_t len;
        char *ret;
 
-       if (strlen(p) < n)
-               n = strlen(p);
-       ret = tal_memdup(ctx, p, n+1);
+       /* We have to let through NULL for take(). */
+       if (likely(p)) {
+               len = strlen(p);
+               if (len > n)
+                       len = n;
+       } else
+               len = n;
+
+       ret = tal_dup(ctx, char, p, len, 1);
        if (ret)
-               ret[n] = '\0';
+               ret[len] = '\0';
        return ret;
 }
 
-void *tal_memdup(const tal_t *ctx, const void *p, size_t n)
+void *tal_dup_(const tal_t *ctx, const void *p, size_t n, size_t extra,
+              const char *label)
 {
        void *ret;
 
-       if (ctx == TAL_TAKE)
-               return (void *)p;
+       /* Beware overflow! */
+       if (n + extra < n || n + extra + sizeof(struct tal_hdr) < n) {
+               call_error("dup size overflow");
+               if (taken(p))
+                       tal_free(p);
+               return NULL;
+       }
 
-       ret = tal_arr(ctx, char, n);
+       if (taken(p)) {
+               if (unlikely(!p))
+                       return NULL;
+               if (unlikely(!tal_resize_((void **)&p, n + extra))) {
+                       tal_free(p);
+                       return NULL;
+               }
+               if (unlikely(!tal_steal(ctx, p))) {
+                       tal_free(p);
+                       return NULL;
+               }
+               return (void *)p;
+       }
+       ret = tal_alloc_(ctx, n + extra, false, label);
        if (ret)
                memcpy(ret, p, n);
        return ret;
@@ -741,15 +787,16 @@ char *tal_asprintf(const tal_t *ctx, const char *fmt, ...)
 
 char *tal_vasprintf(const tal_t *ctx, const char *fmt, va_list ap)
 {
-       size_t max = strlen(fmt) * 2;
+       size_t max;
        char *buf;
        int ret;
 
-       if (ctx == TAL_TAKE)
-               buf = tal_arr(tal_parent(fmt), char, max);
-       else
-               buf = tal_arr(ctx, char, max);
+       if (!fmt && taken(fmt))
+               return NULL;
 
+       /* A decent guess to start. */
+       max = strlen(fmt) * 2;
+       buf = tal_arr(ctx, char, max);
        while (buf) {
                va_list ap2;
 
@@ -764,7 +811,7 @@ char *tal_vasprintf(const tal_t *ctx, const char *fmt, va_list ap)
                        buf = NULL;
                }
        }
-       if (ctx == TAL_TAKE)
+       if (taken(fmt))
                tal_free(fmt);
        return buf;
 }