Remove openvpn_snprintf and similar functions

Old Microsoft versions did strange behaviour but according to the
newly added unit test and
https://stackoverflow.com/questions/7706936/is-snprintf-always-null-terminating
this is now standard conforming and we can use the normal snprintf
method.

Microsoft own documentation to swprintf also says you nowadays need to
define _CRT_NON_CONFORMING_SWPRINTFS to get to non-standard behaviour.

Change-Id: I07096977e3b562bcb5d2c6f11673a4175b8e12ac
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Frank Lichtenheld <frank@lichtenheld.com>
Message-Id: <20240506102710.8976-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg28617.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

src/openvpn/buffer.c

@@ -279,32 +279,6 @@ buf_puts(struct buffer *buf, const char *str)
     return ret;
 }
 
-
-/*
- * This is necessary due to certain buggy implementations of snprintf,
- * that don't guarantee null termination for size > 0.
- *
- * Return false on overflow.
- *
- * This functionality is duplicated in src/openvpnserv/common.c
- * Any modifications here should be done to the other place as well.
- */
-
-bool
-openvpn_snprintf(char *str, size_t size, const char *format, ...)
-{
-    va_list arglist;
-    int len = -1;
-    if (size > 0)
-    {
-        va_start(arglist, format);
-        len = vsnprintf(str, size, format, arglist);
-        va_end(arglist);
-        str[size - 1] = 0;
-    }
-    return (len >= 0 && len < size);
-}
-
 /*
  * write a string to the end of a buffer that was
  * truncated by buf_printf

src/openvpn/buffer.h

@@ -448,19 +448,6 @@ __attribute__ ((format(__printf__, 2, 3)))
  */
 bool buf_puts(struct buffer *buf, const char *str);
 
-/*
- * Like snprintf but guarantees null termination for size > 0
- */
-bool openvpn_snprintf(char *str, size_t size, const char *format, ...)
-#ifdef __GNUC__
-#if __USE_MINGW_ANSI_STDIO
-__attribute__ ((format(gnu_printf, 3, 4)))
-#else
-__attribute__ ((format(__printf__, 3, 4)))
-#endif
-#endif
-;
-
 
 /*
  * remove/add trailing characters

src/openvpn/crypto.c

@@ -874,11 +874,11 @@ init_key_ctx_bi(struct key_ctx_bi *ctx, const struct key2 *key2,
 
     key_direction_state_init(&kds, key_direction);
 
-    openvpn_snprintf(log_prefix, sizeof(log_prefix), "Outgoing %s", name);
+    snprintf(log_prefix, sizeof(log_prefix), "Outgoing %s", name);
     init_key_ctx(&ctx->encrypt, &key2->keys[kds.out_key], kt,
                  OPENVPN_OP_ENCRYPT, log_prefix);
 
-    openvpn_snprintf(log_prefix, sizeof(log_prefix), "Incoming %s", name);
+    snprintf(log_prefix, sizeof(log_prefix), "Incoming %s", name);
     init_key_ctx(&ctx->decrypt, &key2->keys[kds.in_key], kt,
                  OPENVPN_OP_DECRYPT, log_prefix);
 

src/openvpn/crypto_mbedtls.c

@@ -128,7 +128,7 @@ mbed_log_func_line(unsigned int flags, int errval, const char *func,
 {
     char prefix[256];
 
-    if (!openvpn_snprintf(prefix, sizeof(prefix), "%s:%d", func, line))
+    if (!snprintf(prefix, sizeof(prefix), "%s:%d", func, line))
     {
         return mbed_log_err(flags, errval, func);
     }
@@ -239,11 +239,11 @@ crypto_pem_encode(const char *name, struct buffer *dst,
     char header[1000+1] = { 0 };
     char footer[1000+1] = { 0 };
 
-    if (!openvpn_snprintf(header, sizeof(header), "-----BEGIN %s-----\n", name))
+    if (!snprintf(header, sizeof(header), "-----BEGIN %s-----\n", name))
     {
         return false;
     }
-    if (!openvpn_snprintf(footer, sizeof(footer), "-----END %s-----\n", name))
+    if (!snprintf(footer, sizeof(footer), "-----END %s-----\n", name))
     {
         return false;
     }
@@ -278,11 +278,11 @@ crypto_pem_decode(const char *name, struct buffer *dst,
     char header[1000+1] = { 0 };
     char footer[1000+1] = { 0 };
 
-    if (!openvpn_snprintf(header, sizeof(header), "-----BEGIN %s-----", name))
+    if (!snprintf(header, sizeof(header), "-----BEGIN %s-----", name))
     {
         return false;
     }
-    if (!openvpn_snprintf(footer, sizeof(footer), "-----END %s-----", name))
+    if (!snprintf(footer, sizeof(footer), "-----END %s-----", name))
     {
         return false;
     }

src/openvpn/dns.c

@@ -349,11 +349,11 @@ setenv_dns_option(struct env_set *es,
 
     if (j < 0)
     {
-        name_ok = openvpn_snprintf(name, sizeof(name), format, i);
+        name_ok = snprintf(name, sizeof(name), format, i);
     }
     else
     {
-        name_ok = openvpn_snprintf(name, sizeof(name), format, i, j);
+        name_ok = snprintf(name, sizeof(name), format, i, j);
     }
 
     if (!name_ok)

src/openvpn/env_set.c

@@ -259,23 +259,23 @@ void
 setenv_counter(struct env_set *es, const char *name, counter_type value)
 {
     char buf[64];
-    openvpn_snprintf(buf, sizeof(buf), counter_format, value);
+    snprintf(buf, sizeof(buf), counter_format, value);
     setenv_str(es, name, buf);
 }
 
 void
 setenv_int(struct env_set *es, const char *name, int value)
 {
     char buf[64];
-    openvpn_snprintf(buf, sizeof(buf), "%d", value);
+    snprintf(buf, sizeof(buf), "%d", value);
     setenv_str(es, name, buf);
 }
 
 void
 setenv_long_long(struct env_set *es, const char *name, long long value)
 {
     char buf[64];
-    openvpn_snprintf(buf, sizeof(buf), "%" PRIi64, (int64_t)value);
+    snprintf(buf, sizeof(buf), "%" PRIi64, (int64_t)value);
     setenv_str(es, name, buf);
 }
 
@@ -310,7 +310,7 @@ setenv_str_incr(struct env_set *es, const char *name, const char *value)
     strcpy(tmpname, name);
     while (NULL != env_set_get(es, tmpname) && counter < 1000)
     {
-        ASSERT(openvpn_snprintf(tmpname, tmpname_len, "%s_%u", name, counter));
+        ASSERT(snprintf(tmpname, tmpname_len, "%s_%u", name, counter));
         counter++;
     }
     if (counter < 1000)

src/openvpn/error.c

@@ -274,14 +274,14 @@ x_msg_va(const unsigned int flags, const char *format, va_list arglist)
 
     if ((flags & M_ERRNO) && e)
     {
-        openvpn_snprintf(m2, ERR_BUF_SIZE, "%s: %s (errno=%d)",
-                         m1, openvpn_strerror(e, crt_error, &gc), e);
+        snprintf(m2, ERR_BUF_SIZE, "%s: %s (errno=%d)",
+                 m1, openvpn_strerror(e, crt_error, &gc), e);
         SWAP;
     }
 
     if (flags & M_OPTERR)
     {
-        openvpn_snprintf(m2, ERR_BUF_SIZE, "Options error: %s", m1);
+        snprintf(m2, ERR_BUF_SIZE, "Options error: %s", m1);
         SWAP;
     }
 
@@ -321,10 +321,10 @@ x_msg_va(const unsigned int flags, const char *format, va_list arglist)
         const struct virtual_output *vo = msg_get_virtual_output();
         if (vo)
         {
-            openvpn_snprintf(m2, ERR_BUF_SIZE, "%s%s%s",
-                             prefix,
-                             prefix_sep,
-                             m1);
+            snprintf(m2, ERR_BUF_SIZE, "%s%s%s",
+                     prefix,
+                     prefix_sep,
+                     m1);
             virtual_output_print(vo, flags, m2);
         }
     }

src/openvpn/init.c

@@ -359,7 +359,7 @@ management_callback_remote_entry_get(void *arg, unsigned int index, char **remot
         char *out = malloc(len);
         check_malloc_return(out);
 
-        openvpn_snprintf(out, len, "%s,%s,%s,%s", ce->remote, ce->remote_port, proto, status);
+        snprintf(out, len, "%s,%s,%s,%s", ce->remote, ce->remote_port, proto, status);
         *remote = out;
     }
     else

src/openvpn/manage.c

@@ -515,8 +515,8 @@ man_bytecount_output_client(struct management *man,
     char out[32];
 
     /* do in a roundabout way to work around possible mingw or mingw-glibc bug */
-    openvpn_snprintf(in, sizeof(in), counter_format, man->persist.bytes_in + dco_read_bytes);
-    openvpn_snprintf(out, sizeof(out), counter_format, man->persist.bytes_out + dco_write_bytes);
+    snprintf(in, sizeof(in), counter_format, man->persist.bytes_in + dco_read_bytes);
+    snprintf(out, sizeof(out), counter_format, man->persist.bytes_out + dco_write_bytes);
     msg(M_CLIENT, ">BYTECOUNT:%s,%s", in, out);
 }
 
@@ -528,8 +528,8 @@ man_bytecount_output_server(const counter_type *bytes_in_total,
     char in[32];
     char out[32];
     /* do in a roundabout way to work around possible mingw or mingw-glibc bug */
-    openvpn_snprintf(in, sizeof(in), counter_format, *bytes_in_total);
-    openvpn_snprintf(out, sizeof(out), counter_format, *bytes_out_total);
+    snprintf(in, sizeof(in), counter_format, *bytes_in_total);
+    snprintf(out, sizeof(out), counter_format, *bytes_out_total);
     msg(M_CLIENT, ">BYTECOUNT_CLI:%lu,%s,%s", mdac->cid, in, out);
     mdac->bytecount_last_update = now;
 }

src/openvpn/options.c

@@ -1427,7 +1427,7 @@ foreign_options_copy_dns(struct options *o, struct env_set *es)
     for (int i = 1; i <= opt_max; ++i)
     {
         char name[32];
-        openvpn_snprintf(name, sizeof(name), "foreign_option_%d", i);
+        snprintf(name, sizeof(name), "foreign_option_%d", i);
 
         const char *env_str = env_set_get(es, name);
         const char *value = strchr(env_str, '=') + 1;
@@ -1482,7 +1482,7 @@ foreign_options_copy_dns(struct options *o, struct env_set *es)
     while (o->foreign_option_index < opt_max)
     {
         char name[32];
-        openvpn_snprintf(name, sizeof(name), "foreign_option_%d", opt_max--);
+        snprintf(name, sizeof(name), "foreign_option_%d", opt_max--);
         setenv_del(es, name);
     }
 }
@@ -5674,8 +5674,8 @@ set_user_script(struct options *options,
 #ifndef ENABLE_SMALL
     {
         char script_name[100];
-        openvpn_snprintf(script_name, sizeof(script_name),
-                         "--%s script", type);
+        snprintf(script_name, sizeof(script_name),
+                 "--%s script", type);
 
         if (check_cmd_access(*script, script_name, (in_chroot ? options->chroot_dir : NULL)))
         {

src/openvpn/pkcs11.c

@@ -201,7 +201,7 @@ _pkcs11_openvpn_token_prompt(
     CLEAR(token_resp);
     token_resp.defined = false;
     token_resp.nocache = true;
-    openvpn_snprintf(
+    snprintf(
         token_resp.username,
         sizeof(token_resp.username),
         "Please insert %s token",
@@ -245,7 +245,7 @@ _pkcs11_openvpn_pin_prompt(
 
     ASSERT(token!=NULL);
 
-    openvpn_snprintf(prompt, sizeof(prompt), "%s token", token->label);
+    snprintf(prompt, sizeof(prompt), "%s token", token->label);
 
     token_pass.defined = false;
     token_pass.nocache = true;
@@ -719,7 +719,7 @@ tls_ctx_use_pkcs11(
 
         id_resp.defined = false;
         id_resp.nocache = true;
-        openvpn_snprintf(
+        snprintf(
             id_resp.username,
             sizeof(id_resp.username),
             "Please specify PKCS#11 id to use"

src/openvpn/platform.c

@@ -564,9 +564,9 @@ platform_create_temp_file(const char *directory, const char *prefix, struct gc_a
     {
         ++attempts;
 
-        if (!openvpn_snprintf(fname, sizeof(fname), fname_fmt, max_prefix_len,
-                              prefix, (unsigned long) get_random(),
-                              (unsigned long) get_random()))
+        if (!snprintf(fname, sizeof(fname), fname_fmt, max_prefix_len,
+                      prefix, (unsigned long) get_random(),
+                      (unsigned long) get_random()))
         {
             msg(M_WARN, "ERROR: temporary filename too long");
             return NULL;

src/openvpn/plugin.c

@@ -260,7 +260,7 @@ plugin_init_item(struct plugin *p, const struct plugin_option *o)
     {
         char full[PATH_MAX];
 
-        openvpn_snprintf(full, sizeof(full), "%s/%s", PLUGIN_LIBDIR, p->so_pathname);
+        snprintf(full, sizeof(full), "%s/%s", PLUGIN_LIBDIR, p->so_pathname);
         p->handle = dlopen(full, RTLD_NOW);
     }
     else
@@ -409,7 +409,7 @@ plugin_vlog(openvpn_plugin_log_flags_t flags, const char *name, const char *form
 
         gc_init(&gc);
         msg_fmt = gc_malloc(ERR_BUF_SIZE, false, &gc);
-        openvpn_snprintf(msg_fmt, ERR_BUF_SIZE, "PLUGIN %s: %s", name, format);
+        snprintf(msg_fmt, ERR_BUF_SIZE, "PLUGIN %s: %s", name, format);
         x_msg_va(msg_flags, msg_fmt, arglist);
 
         gc_free(&gc);

src/openvpn/pool.c

@@ -766,7 +766,7 @@ ifconfig_pool_test(in_addr_t start, in_addr_t end)
         ifconfig_pool_handle h;
         in_addr_t local, remote;
         char buf[256];
-        openvpn_snprintf(buf, sizeof(buf), "common-name-%d", i);
+        snprintf(buf, sizeof(buf), "common-name-%d", i);
 #ifdef DUP_CN
         cn = NULL;
 #else