tal: tal_dup()

Sometimes you want to duplicate and enlarge in one step: particularly with
TAL_TAKE.  It's also typesafe, unlike tal_memdup().

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/ccan/tal/tal.c b/ccan/tal/tal.c
index ffe2d71334dce4473d57243bca0827aaa5fee565..88bcb5ab6135257529eda0e999df024507c0386d 100644 (file)
--- a/ccan/tal/tal.c
+++ b/ccan/tal/tal.c
@@ -665,6 +665,12 @@ bool tal_resize_(tal_t **ctxp, size_t size)
 
         old_t = debug_tal(to_tal_hdr(*ctxp));
 
 
         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");
         t = resizefn(old_t, size + sizeof(struct tal_hdr));
        if (!t) {
                call_error("Reallocation failure");


@@ -699,7 +705,7 @@ bool tal_resize_(tal_t **ctxp, size_t size)
 
 char *tal_strdup(const tal_t *ctx, const char *p)
 {
 
 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)
 }
 
 char *tal_strndup(const tal_t *ctx, const char *p, size_t n)


@@ -708,20 +714,35 @@ char *tal_strndup(const tal_t *ctx, const char *p, size_t n)
 
        if (strlen(p) < n)
                n = strlen(p);
 
        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;
 }
 
        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;
 
 {
        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;
        if (ret)
                memcpy(ret, p, n);
        return ret;

diff --git a/ccan/tal/tal.h b/ccan/tal/tal.h
index 28726c324cedd9ec4c150bcd02f369c6e6180905..b047b3894c95786e71face627907506bb7a34ff9 100644 (file)
--- a/ccan/tal/tal.h
+++ b/ccan/tal/tal.h
@@ -188,13 +188,18 @@ tal_t *tal_next(const tal_t *root, const tal_t *prev);
 tal_t *tal_parent(const tal_t *ctx);
 
 /**
 tal_t *tal_parent(const tal_t *ctx);
 
 /**

- * tal_memdup - duplicate memory.
+ * tal_dup - duplicate an array.

  * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
  * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).

- * @p: the memory to copy
- * @n: the number of bytes.
- *
+ * @type: the type (should match type of @p!)
+ * @p: the array to copy
+ * @n: the number of sizeof(type) entries to copy.
+ * @extra: the number of extra sizeof(type) entries to allocate.

  */
  */

-void *tal_memdup(const tal_t *ctx, const void *p, size_t n);
+#define tal_dup(ctx, type, p, n, extra)                                \
+       ((type *)tal_dup_((ctx), tal_typechk_(p, type *),       \
+                         tal_sizeof_(sizeof(type), (n)),       \
+                         tal_sizeof_(sizeof(type), (extra)),   \
+                         TAL_LABEL(type, "[]")))

 
 /**
  * tal_strdup - duplicate a string
 
 /**
  * tal_strdup - duplicate a string


@@ -315,12 +320,23 @@ static inline size_t tal_sizeof_(size_t size, size_t count)
 
 #if HAVE_TYPEOF
 #define tal_typeof(ptr) (__typeof__(ptr))
 
 #if HAVE_TYPEOF
 #define tal_typeof(ptr) (__typeof__(ptr))

+#if HAVE_STATEMENT_EXPR
+/* Careful: ptr can be const foo *, ptype is foo *.  Also, ptr could
+ * be an array, eg "hello". */
+#define tal_typechk_(ptr, ptype) ({ __typeof__(&*(ptr)) _p = (ptype)(ptr); _p; })

 #else
 #else

+#define tal_typechk_(ptr, ptype) (ptr)
+#endif
+#else /* !HAVE_TYPEOF */

 #define tal_typeof(ptr)
 #define tal_typeof(ptr)

+#define tal_typechk_(ptr, ptype) (ptr)

 #endif
 
 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label);
 
 #endif
 
 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label);
 

+void *tal_dup_(const tal_t *ctx, const void *p, size_t n, size_t extra,
+              const char *label);
+

 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
 
 bool tal_resize_(tal_t **ctxp, size_t size);
 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
 
 bool tal_resize_(tal_t **ctxp, size_t size);

diff --git a/ccan/tal/test/run-overflow.c b/ccan/tal/test/run-overflow.c
index dedeba3d112ee2195c07a512b05338f1438a3f25..6c4ccff4379dc97d4be669d8fe2c5224086c5618 100644 (file)
--- a/ccan/tal/test/run-overflow.c
+++ b/ccan/tal/test/run-overflow.c
@@ -7,14 +7,14 @@ static int error_count;
 static void my_error(const char *msg)
 {
        error_count++;
 static void my_error(const char *msg)
 {
        error_count++;

-       ok1(strstr(msg, "overflow"));

 }
 
 int main(void)
 {
        void *p;
 }
 
 int main(void)
 {
        void *p;

+       int *pi, *origpi;

 
 

-       plan_tests(6);
+       plan_tests(26);

 
        tal_set_backend(NULL, NULL, NULL, my_error);
 
 
        tal_set_backend(NULL, NULL, NULL, my_error);
 


@@ -25,5 +25,60 @@ int main(void)
        p = tal_arr(NULL, char, (size_t)-2);
        ok1(!p);
        ok1(error_count == 2);
        p = tal_arr(NULL, char, (size_t)-2);
        ok1(!p);
        ok1(error_count == 2);

+
+       /* Now try overflow cases for tal_dup. */
+       error_count = 0;
+       pi = origpi = tal_arr(NULL, int, 100);
+       ok1(pi);
+       ok1(error_count == 0);
+       pi = tal_dup(NULL, int, pi, (size_t)-1, 0);
+       ok1(!pi);
+       ok1(error_count == 1);
+       pi = tal_dup(NULL, int, pi, 0, (size_t)-1);
+       ok1(!pi);
+       ok1(error_count == 2);
+
+       pi = tal_dup(NULL, int, pi, (size_t)-1UL / sizeof(int),
+                    (size_t)-1UL / sizeof(int));
+       ok1(!pi);
+       ok1(error_count == 3);
+       /* This will still overflow when tal_hdr is added. */
+       pi = tal_dup(NULL, int, pi, (size_t)-1UL / sizeof(int) / 2,
+                    (size_t)-1UL / sizeof(int) / 2);
+       ok1(!pi);
+       ok1(error_count == 4);
+
+       /* Now, check that with TAL_TAKE we free old one on failure. */
+       pi = tal_arr(NULL, int, 100);
+       error_count = 0;
+       pi = tal_dup(TAL_TAKE, int, pi, (size_t)-1, 0);
+       ok1(!pi);
+       ok1(error_count == 1);
+       ok1(tal_first(NULL) == origpi && !tal_next(NULL, origpi));
+
+       pi = tal_arr(NULL, int, 100);
+       error_count = 0;
+       pi = tal_dup(TAL_TAKE, int, pi, 0, (size_t)-1);
+       ok1(!pi);
+       ok1(error_count == 1);
+       ok1(tal_first(NULL) == origpi && !tal_next(NULL, origpi));
+
+       pi = tal_arr(NULL, int, 100);
+       error_count = 0;
+       pi = tal_dup(TAL_TAKE, int, pi, (size_t)-1UL / sizeof(int),
+                    (size_t)-1UL / sizeof(int));
+       ok1(!pi);
+       ok1(error_count == 1);
+       ok1(tal_first(NULL) == origpi && !tal_next(NULL, origpi));
+
+       pi = tal_arr(NULL, int, 100);
+       error_count = 0;
+       /* This will still overflow when tal_hdr is added. */
+       pi = tal_dup(TAL_TAKE, int, pi, (size_t)-1UL / sizeof(int) / 2,
+                    (size_t)-1UL / sizeof(int) / 2);
+       ok1(!pi);
+       ok1(error_count == 1);
+       ok1(tal_first(NULL) == origpi && !tal_next(NULL, origpi));
+

        return exit_status();
 }
        return exit_status();
 }

diff --git a/ccan/tal/test/run-string.c b/ccan/tal/test/run-string.c
index 43a99da41db041f2b5675540d80e8651ac735314..0155ecbe9212f3b997c39727c3b530bc822abeb0 100644 (file)
--- a/ccan/tal/test/run-string.c
+++ b/ccan/tal/test/run-string.c
@@ -6,7 +6,7 @@ int main(void)
 {
        char *parent, *c;
 
 {
        char *parent, *c;
 

-       plan_tests(9);
+       plan_tests(13);

 
        parent = tal(NULL, char);
        ok1(parent);
 
        parent = tal(NULL, char);
        ok1(parent);


@@ -19,10 +19,19 @@ int main(void)
        ok1(strcmp(c, "hel") == 0);
        ok1(tal_parent(c) == parent);
 
        ok1(strcmp(c, "hel") == 0);
        ok1(tal_parent(c) == parent);
 

-       c = tal_memdup(parent, "hello", 6);
+       c = tal_typechk_(parent, char *);
+       c = tal_dup(parent, char, "hello", 6, 0);

        ok1(strcmp(c, "hello") == 0);
        ok1(strcmp(c, "hello") == 0);

+       ok1(strcmp(tal_name(c), "char[]") == 0);

        ok1(tal_parent(c) == parent);
 
        ok1(tal_parent(c) == parent);
 

+       /* Now with an extra byte. */
+       c = tal_dup(parent, char, "hello", 6, 1);
+       ok1(strcmp(c, "hello") == 0);
+       ok1(strcmp(tal_name(c), "char[]") == 0);
+       ok1(tal_parent(c) == parent);
+       strcat(c, "x");
+

        c = tal_asprintf(parent, "hello %s", "there");
        ok1(strcmp(c, "hello there") == 0);
        ok1(tal_parent(c) == parent);
        c = tal_asprintf(parent, "hello %s", "there");
        ok1(strcmp(c, "hello there") == 0);
        ok1(tal_parent(c) == parent);

diff --git a/ccan/tal/test/run-take.c b/ccan/tal/test/run-take.c
index dbc78a33b83a1d3a9ffcd654e3a2400851c87f91..53c1a44a85390e419075268efb157617390be71d 100644 (file)
--- a/ccan/tal/test/run-take.c
+++ b/ccan/tal/test/run-take.c
@@ -6,7 +6,7 @@ int main(void)
 {
        char *parent, *c;
 
 {
        char *parent, *c;
 

-       plan_tests(13);
+       plan_tests(15);

 
        parent = tal(NULL, char);
        ok1(parent);
 
        parent = tal(NULL, char);
        ok1(parent);


@@ -25,10 +25,15 @@ int main(void)
        ok1(strcmp(c, "hel") == 0);
        ok1(tal_parent(c) == parent);
 
        ok1(strcmp(c, "hel") == 0);
        ok1(tal_parent(c) == parent);
 

-       c = tal_memdup(TAL_TAKE, c, 1);
+       c = tal_dup(TAL_TAKE, char, c, 1, 0);

        ok1(c[0] == 'h');
        ok1(tal_parent(c) == parent);
 
        ok1(c[0] == 'h');
        ok1(tal_parent(c) == parent);
 

+       c = tal_dup(TAL_TAKE, char, c, 1, 2);
+       ok1(c[0] == 'h');
+       strcpy(c, "hi");
+       ok1(tal_parent(c) == parent);
+

        /* No leftover allocations. */
        tal_free(c);
        ok1(tal_first(parent) == NULL);
        /* No leftover allocations. */
        tal_free(c);
        ok1(tal_first(parent) == NULL);