[or-cvs] [tor/master 1/3] Add a tor_asprintf() function, and use it in a couple of places.
nickm at torproject.org
nickm at torproject.org
Fri Apr 2 16:33:20 UTC 2010
Author: Nick Mathewson <nickm at torproject.org>
Date: Thu, 25 Feb 2010 15:58:55 -0500
Subject: Add a tor_asprintf() function, and use it in a couple of places.
Commit: 6fa8dacb97587707156507aa35141e414fc284bb
asprintf() is a GNU extension that some BSDs have picked up: it does a printf
into a newly allocated chunk of RAM.
Our tor_asprintf() differs from standard asprintf() in that:
- Like our other malloc functions, it asserts on OOM.
- It works on windows.
- It always sets its return-field.
---
configure.in | 2 +-
src/common/compat.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++
src/common/compat.h | 4 ++
src/or/circuitbuild.c | 14 ++++----
src/test/test_util.c | 46 ++++++++++++++++++++++++++
5 files changed, 144 insertions(+), 8 deletions(-)
diff --git a/configure.in b/configure.in
index e045c08..e948503 100644
--- a/configure.in
+++ b/configure.in
@@ -189,7 +189,7 @@ dnl -------------------------------------------------------------------
dnl Check for functions before libevent, since libevent-1.2 apparently
dnl exports strlcpy without defining it in a header.
-AC_CHECK_FUNCS(gettimeofday ftime socketpair uname inet_aton strptime getrlimit strlcat strlcpy strtoull getaddrinfo localtime_r gmtime_r memmem strtok_r writev readv flock prctl)
+AC_CHECK_FUNCS(gettimeofday ftime socketpair uname inet_aton strptime getrlimit strlcat strlcpy strtoull getaddrinfo localtime_r gmtime_r memmem strtok_r writev readv flock prctl vasprintf)
using_custom_malloc=no
if test x$enable_openbsd_malloc = xyes ; then
diff --git a/src/common/compat.c b/src/common/compat.c
index 406d74e..49e66c6 100644
--- a/src/common/compat.c
+++ b/src/common/compat.c
@@ -307,6 +307,92 @@ tor_vsnprintf(char *str, size_t size, const char *format, va_list args)
return r;
}
+/**
+ * Portable asprintf implementation. Does a printf() into a newly malloc'd
+ * string. Sets *<b>strp</b> to this string, and returns its length (not
+ * including the terminating NUL character).
+ *
+ * You can treat this function as if its implementation were something like
+ <pre>
+ char buf[_INFINITY_];
+ tor_snprintf(buf, sizeof(buf), fmt, args);
+ *strp = tor_strdup(buf);
+ return strlen(*strp):
+ </pre>
+ * Where _INFINITY_ is an imaginary constant so big that any string can fit
+ * into it.
+ */
+int
+tor_asprintf(char **strp, const char *fmt, ...)
+{
+ int r;
+ va_list args;
+ va_start(args, fmt);
+ r = tor_vasprintf(strp, fmt, args);
+ va_end(args);
+ if (!*strp || r < 0) {
+ log_err(LD_BUG, "Internal error in asprintf");
+ tor_assert(0);
+ }
+ return r;
+}
+
+/**
+ * Portable vasprintf implementation. Does a printf() into a newly malloc'd
+ * string. Differs from regular vasprintf in the same ways that
+ * tor_asprintf() differs from regular asprintf.
+ */
+int
+tor_vasprintf(char **strp, const char *fmt, va_list args)
+{
+#ifdef HAVE_VASPRINTF
+ /* If the platform gives us one, use it. */
+ int r = vasprintf(strp, fmt, args);
+ if (r < 0)
+ *strp = NULL;
+ return r;
+#elif defined(MS_WINDOWS)
+ /* On Windows, _vsnprintf won't tell us the length of the string if it
+ * overflows, so we need to use _vcsprintf to tell how much to allocate */
+ int len, r;
+ char *res;
+ len = _vcsprintf(fmt, args);
+ if (len < 0) {
+ strp = NULL;
+ return -1;
+ }
+ *strp = tor_malloc(len + 1);
+ r = _vsnprintf(*strp, len+1, fmt, args);
+ if (r != len) {
+ tor_free(*strp);
+ return -1;
+ }
+ return len;
+#else
+ /* Everywhere else, we have a decent vsnprintf that tells us how many
+ * characters we need. We give it a try on a short buffer first, since
+ * it might be nice to avoid the second vsnprintf call.
+ */
+ char buf[128];
+ int len, r;
+ va_list tmp_args;
+ va_copy(tmp_args, args);
+ len = vsnprintf(buf, sizeof(buf), fmt, tmp_args);
+ va_end(tmp_args);
+ if (len < (int)sizeof(buf)) {
+ *strp = tor_strdup(buf);
+ return len;
+ }
+ *strp = tor_malloc(len+1);
+ r = vsnprintf(*strp, len+1, fmt, args);
+ if (r != len) {
+ tor_free(*strp);
+ return -1;
+ }
+ return len;
+#endif
+}
+
/** Given <b>hlen</b> bytes at <b>haystack</b> and <b>nlen</b> bytes at
* <b>needle</b>, return a pointer to the first occurrence of the needle
* within the haystack, or NULL if there is no such occurrence.
diff --git a/src/common/compat.h b/src/common/compat.h
index 554ae89..f3e3045 100644
--- a/src/common/compat.h
+++ b/src/common/compat.h
@@ -235,6 +235,10 @@ int tor_snprintf(char *str, size_t size, const char *format, ...)
int tor_vsnprintf(char *str, size_t size, const char *format, va_list args)
ATTR_NONNULL((1,3));
+int tor_asprintf(char **strp, const char *fmt, ...)
+ CHECK_PRINTF(2,3);
+int tor_vasprintf(char **strp, const char *fmt, va_list args);
+
const void *tor_memmem(const void *haystack, size_t hlen, const void *needle,
size_t nlen) ATTR_PURE ATTR_NONNULL((1,3));
static const void *tor_memstr(const void *haystack, size_t hlen,
diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index 08ee584..cb9ba9e 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -1086,21 +1086,21 @@ circuit_list_path_impl(origin_circuit_t *circ, int verbose, int verbose_names)
crypt_path_t *hop;
smartlist_t *elements;
const char *states[] = {"closed", "waiting for keys", "open"};
- char buf[128];
char *s;
elements = smartlist_create();
if (verbose) {
const char *nickname = build_state_get_exit_nickname(circ->build_state);
- tor_snprintf(buf, sizeof(buf), "%s%s circ (length %d%s%s):",
+ char *cp;
+ tor_asprintf(&cp, "%s%s circ (length %d%s%s):",
circ->build_state->is_internal ? "internal" : "exit",
circ->build_state->need_uptime ? " (high-uptime)" : "",
circ->build_state->desired_path_len,
circ->_base.state == CIRCUIT_STATE_OPEN ? "" : ", exit ",
circ->_base.state == CIRCUIT_STATE_OPEN ? "" :
(nickname?nickname:"*unnamed*"));
- smartlist_add(elements, tor_strdup(buf));
+ smartlist_add(elements, cp);
}
hop = circ->cpath;
@@ -3067,21 +3067,21 @@ static void
log_entry_guards(int severity)
{
smartlist_t *elements = smartlist_create();
- char buf[1024];
char *s;
SMARTLIST_FOREACH(entry_guards, entry_guard_t *, e,
{
const char *msg = NULL;
+ char *cp;
if (entry_is_live(e, 0, 1, 0, &msg))
- tor_snprintf(buf, sizeof(buf), "%s (up %s)",
+ tor_asprintf(&cp, "%s (up %s)",
e->nickname,
e->made_contact ? "made-contact" : "never-contacted");
else
- tor_snprintf(buf, sizeof(buf), "%s (%s, %s)",
+ tor_asprintf(&cp, "%s (%s, %s)",
e->nickname, msg,
e->made_contact ? "made-contact" : "never-contacted");
- smartlist_add(elements, tor_strdup(buf));
+ smartlist_add(elements, cp);
});
s = smartlist_join_strings(elements, ",", 0, NULL);
diff --git a/src/test/test_util.c b/src/test/test_util.c
index ad8d82b..0e40ae4 100644
--- a/src/test/test_util.c
+++ b/src/test/test_util.c
@@ -1050,6 +1050,51 @@ test_util_find_str_at_start_of_line(void *ptr)
;
}
+static void
+test_util_asprintf(void *ptr)
+{
+#define LOREMIPSUM \
+ "Lorem ipsum dolor sit amet, consectetur adipisicing elit"
+ char *cp=NULL, *cp2=NULL;
+ int r;
+ (void)ptr;
+
+ /* empty string. */
+ r = tor_asprintf(&cp, "%s", "");
+ tt_assert(cp);
+ tt_int_op(r, ==, strlen(cp));
+ tt_str_op(cp, ==, "");
+
+ /* Short string with some printing in it. */
+ r = tor_asprintf(&cp2, "First=%d, Second=%d", 101, 202);
+ tt_assert(cp2);
+ tt_int_op(r, ==, strlen(cp2));
+ tt_str_op(cp2, ==, "First=101, Second=202");
+ tt_assert(cp != cp2);
+ tor_free(cp);
+ tor_free(cp2);
+
+ /* Glass-box test: a string exactly 128 characters long. */
+ r = tor_asprintf(&cp, "Lorem1: %sLorem2: %s", LOREMIPSUM, LOREMIPSUM);
+ tt_assert(cp);
+ tt_int_op(r, ==, 128);
+ tt_assert(cp[128] == '\0');
+ tt_str_op(cp, ==,
+ "Lorem1: "LOREMIPSUM"Lorem2: "LOREMIPSUM);
+ tor_free(cp);
+
+ /* String longer than 128 characters */
+ r = tor_asprintf(&cp, "1: %s 2: %s 3: %s",
+ LOREMIPSUM, LOREMIPSUM, LOREMIPSUM);
+ tt_assert(cp);
+ tt_int_op(r, ==, strlen(cp));
+ tt_str_op(cp, ==, "1: "LOREMIPSUM" 2: "LOREMIPSUM" 3: "LOREMIPSUM);
+
+ done:
+ tor_free(cp);
+ tor_free(cp2);
+}
+
#define UTIL_LEGACY(name) \
{ #name, legacy_test_helper, 0, &legacy_setup, test_util_ ## name }
@@ -1071,6 +1116,7 @@ struct testcase_t util_tests[] = {
UTIL_LEGACY(sscanf),
UTIL_LEGACY(strtok),
UTIL_TEST(find_str_at_start_of_line, 0),
+ UTIL_TEST(asprintf, 0),
END_OF_TESTCASES
};
--
1.6.5
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