tal: tal_dup()

[ccan] / ccan / tal / tal.c

diff --git a/ccan/tal/tal.c b/ccan/tal/tal.c
index ff25db19afb8a3b16da50ef254687a85b50cc71e..88bcb5ab6135257529eda0e999df024507c0386d 100644 (file)
--- a/ccan/tal/tal.c
+++ b/ccan/tal/tal.c
@@ -9,6 +9,7 @@
 #include <stddef.h>
 #include <string.h>
 #include <limits.h>
+#include <errno.h>
 
 //#define TAL_DEBUG 1
 
@@ -455,6 +456,7 @@ static struct tal_hdr *remove_node(struct tal_hdr *t)
 
                /* Are we the only one? */
                if (prev == t) {
+                       struct prop_hdr *next = (*prop)->next;
                        struct children *c = group->parent_child;
                        /* Is this the group embedded in the child property? */
                        if (group == &c->group) {
@@ -462,9 +464,9 @@ static struct tal_hdr *remove_node(struct tal_hdr *t)
                        } else {
                                /* Empty group, so free it. */
                                list_del_from(&c->group.list, &group->list.n);
-                               *prop = group->hdr.next;
                                freefn(group);
                        }
+                       *prop = next;
                        return c->parent;
                } else {
                        /* Move property to next node. */
@@ -481,6 +483,7 @@ static struct tal_hdr *remove_node(struct tal_hdr *t)
 void tal_free(const tal_t *ctx)
 {
         struct tal_hdr *t;
+       int saved_errno = errno;
 
         if (!ctx)
                 return;
@@ -488,6 +491,7 @@ void tal_free(const tal_t *ctx)
         t = debug_tal(to_tal_hdr(ctx));
         remove_node(t);
         del_tree(t);
+       errno = saved_errno;
 }
 
 void *tal_steal_(const tal_t *new_parent, const tal_t *ctx)
@@ -653,22 +657,29 @@ tal_t *tal_parent(const tal_t *ctx)
         return from_tal_hdr(group->parent_child->parent);
 }
 
-void *tal_realloc_(tal_t *ctx, size_t size)
+bool tal_resize_(tal_t **ctxp, size_t size)
 {
         struct tal_hdr *old_t, *t, **prev;
         struct group *group;
         struct children *child;
 
-        old_t = debug_tal(to_tal_hdr(ctx));
+        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");
-               tal_free(old_t);
-               return NULL;
+               return false;
        }
+
+       /* If it didn't move, we're done! */
         if (t == old_t)
-                return ctx;
+                return true;
        update_bounds(t);
 
        /* Fix up linked list pointer. */
@@ -688,13 +699,13 @@ void *tal_realloc_(tal_t *ctx, size_t size)
                assert(child->parent == old_t);
                child->parent = t;
        }
-
-        return from_tal_hdr(debug_tal(t));
+       *ctxp = from_tal_hdr(debug_tal(t));
+       return true;
 }
 
 char *tal_strdup(const tal_t *ctx, const char *p)
 {
-       return tal_memdup(ctx, p, strlen(p)+1);
+       return tal_dup(ctx, char, p, strlen(p)+1, 0);
 }
 
 char *tal_strndup(const tal_t *ctx, const char *p, size_t n)
@@ -703,20 +714,35 @@ char *tal_strndup(const tal_t *ctx, const char *p, size_t n)
 
        if (strlen(p) < n)
                n = strlen(p);
-       ret = tal_memdup(ctx, p, n+1);
+       ret = tal_dup(ctx, char, p, n, 1);
        if (ret)
                ret[n] = '\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 (ctx == TAL_TAKE)
+                       tal_free(p);
+               return NULL;
+       }
 
-       ret = tal_arr(ctx, char, n);
+       if (ctx == TAL_TAKE) {
+               if (unlikely(!p))
+                       return NULL;
+               if (!tal_resize_((void **)&p, n + extra)) {
+                       tal_free(p);
+                       return NULL;
+               }
+               return (void *)p;
+       }
+       ret = tal_alloc_(ctx, n + extra, false, label);
        if (ret)
                memcpy(ret, p, n);
        return ret;
@@ -754,7 +780,10 @@ char *tal_vasprintf(const tal_t *ctx, const char *fmt, va_list ap)
 
                if (ret < max)
                        break;
-               buf = tal_resize(buf, max *= 2);
+               if (!tal_resize(&buf, max *= 2)) {
+                       tal_free(buf);
+                       buf = NULL;
+               }
        }
        if (ctx == TAL_TAKE)
                tal_free(fmt);