From d76f86f7db59838fa4a2727d7d07710c6cf7470c Mon Sep 17 00:00:00 2001
From: cpq <valenok@gmail.com>
Date: Sat, 13 Aug 2022 15:37:55 +0100
Subject: [PATCH] Get rid of mg_*asprintf

---
 docs/README.md    |  36 +-----------
 mongoose.c        | 136 +++++++++++++---------------------------------
 mongoose.h        |   7 +--
 src/event.c       |   5 +-
 src/fmt.c         |  43 ++-------------
 src/fmt.h         |   4 +-
 src/fs.c          |  23 +++-----
 src/log.c         |  18 +++---
 src/log.h         |   3 +-
 src/tls_mbed.c    |   8 +--
 src/tls_openssl.c |  17 +-----
 src/ws.c          |  22 +++-----
 test/unit_test.c  |  10 +---
 13 files changed, 88 insertions(+), 244 deletions(-)

diff --git a/docs/README.md b/docs/README.md
index ed021133..e411f7a1 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -1473,7 +1473,7 @@ void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
 ### mg\_ws\_send()
 
 ```c
-size_t mg_ws_send(struct mg_connection *c, const char *buf, size_t len, int op);
+size_t mg_ws_send(struct mg_connection *c, const void *buf, size_t len, int op);
 ```
 
 Send data to websocket peer
@@ -1513,7 +1513,7 @@ void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
 
 ```c
 size_t mg_ws_printf(struct mg_connection *, int op, const char *fmt, ...);
-size_t mg_ws_vprintf(struct mg_connection *, int op, const char *fmt, va_list);
+size_t mg_ws_vprintf(struct mg_connection *, int op, const char *fmt, va_list *);
 ```
 
 Same as `mg_ws_send()`, but formats data using `printf()` semantics.
@@ -2602,8 +2602,6 @@ mg_remove_double_dots(data);  // data is /a.txt
 ```c
 size_t mg_snprintf(char *buf, size_t len, const char *fmt, ...);
 size_t mg_vsnprintf(char *buf, size_t len, const char *fmt, va_list ap);
-size_t mg_asprintf(char **buf, size_t len, const char *fmt, ...);
-size_t mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap);
 ```
 
 Print formatted string into a string buffer, just like `snprintf()`
@@ -2663,39 +2661,11 @@ size_t f(void (*out)(char, void *), void *ptr, va_list *ap) {
 }
 ```
 
-### mg\_asprintf(), mg\_vasprintf()
-
-```c
-int mg_asprintf(char **buf, size_t size, const char *fmt, ...);
-int mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap);
-```
-
-Print message specified by printf-like format string `fmt` into a buffer
-pointed by `buf` of size `size`. If `size` is large enough to hold the whole
-message, then a message is stored in `*buf`. If it does not fit, then a large
-enough buffer is allocated to hold a message, and `buf` is changed to point to
-that buffer.
-
-Parameters:
-- `buf` - Pointer to pointer to output buffer
-- `size` - Pre-allocated buffer size
-- `fmt` - printf-like format string
-
-Return value: Number of bytes printed
-
-Usage example:
-
-```c
-char buf[16], *pbuf = buf;
-mg_asprintf(&pbuf, sizeof(buf), "Hello, %s!", "world"); // buf is now "Hello, world!"
-if (pbuf != buf) free(pbuf);
-```
-
 ### mg\_mprintf(), mg\_vmprintf()
 
 ```c
 char *mg_mprintf(const char *fmt, ...);
-char *mg_vmprintf(const char *fmt, va_list ap);
+char *mg_vmprintf(const char *fmt, va_list *ap);
 ```
 
 Print message into an allocated memory buffer. Caller must free the result.
diff --git a/mongoose.c b/mongoose.c
index ecaf7245..c9395162 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -396,15 +396,14 @@ void mg_call(struct mg_connection *c, int ev, void *ev_data) {
 }
 
 void mg_error(struct mg_connection *c, const char *fmt, ...) {
-  char mem[256], *buf = mem;
+  char buf[64];
   va_list ap;
   va_start(ap, fmt);
-  mg_vasprintf(&buf, sizeof(mem), fmt, ap);
+  mg_vsnprintf(buf, sizeof(buf), fmt, &ap);
   va_end(ap);
   MG_ERROR(("%lu %p %s", c->id, c->fd, buf));
   c->is_closing = 1;             // Set is_closing before sending MG_EV_CALL
   mg_call(c, MG_EV_ERROR, buf);  // Let user handler to override it
-  if (buf != mem) free(buf);
 }
 
 #ifdef MG_ENABLE_LINES
@@ -413,37 +412,6 @@ void mg_error(struct mg_connection *c, const char *fmt, ...) {
 
 
 
-size_t mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap) {
-  va_list ap_copy;
-  size_t len;
-
-  va_copy(ap_copy, ap);
-  len = mg_vsnprintf(*buf, size, fmt, &ap_copy);
-  va_end(ap_copy);
-
-  if (len >= size) {
-    //  Allocate a buffer that is large enough
-    if ((*buf = (char *) calloc(1, len + 1)) == NULL) {
-      len = 0;
-    } else {
-      va_copy(ap_copy, ap);
-      len = mg_vsnprintf(*buf, len + 1, fmt, &ap_copy);
-      va_end(ap_copy);
-    }
-  }
-
-  return len;
-}
-
-size_t mg_asprintf(char **buf, size_t size, const char *fmt, ...) {
-  size_t ret;
-  va_list ap;
-  va_start(ap, fmt);
-  ret = mg_vasprintf(buf, size, fmt, ap);
-  va_end(ap);
-  return ret;
-}
-
 size_t mg_snprintf(char *buf, size_t len, const char *fmt, ...) {
   va_list ap;
   size_t n;
@@ -453,17 +421,17 @@ size_t mg_snprintf(char *buf, size_t len, const char *fmt, ...) {
   return n;
 }
 
-char *mg_vmprintf(const char *fmt, va_list ap) {
-  char *s = NULL;
-  mg_vasprintf(&s, 0, fmt, ap);
-  return s;
+char *mg_vmprintf(const char *fmt, va_list *ap) {
+  struct mg_iobuf io = {0, 0, 0, 256};
+  mg_vrprintf(mg_pfn_iobuf, &io, fmt, ap);
+  return (char *) io.buf;
 }
 
 char *mg_mprintf(const char *fmt, ...) {
-  char *s = NULL;
+  char *s;
   va_list ap;
   va_start(ap, fmt);
-  mg_vasprintf(&s, 0, fmt, ap);
+  s = mg_vmprintf(fmt, &ap);
   va_end(ap);
   return s;
 }
@@ -877,32 +845,23 @@ char *mg_file_read(struct mg_fs *fs, const char *path, size_t *sizep) {
 bool mg_file_write(struct mg_fs *fs, const char *path, const void *buf,
                    size_t len) {
   bool result = false;
-  struct mg_fd *fd;
-  char tmp[MG_PATH_MAX];
-  mg_snprintf(tmp, sizeof(tmp), "%s..%d", path, rand());
-  if ((fd = mg_fs_open(fs, tmp, MG_FS_WRITE)) != NULL) {
+  struct mg_fd *fd = mg_fs_open(fs, path, MG_FS_WRITE);
+  if (fd != NULL) {
     result = fs->wr(fd->fd, buf, len) == len;
     mg_fs_close(fd);
-    if (result) {
-      fs->rm(path);
-      fs->mv(tmp, path);
-    } else {
-      fs->rm(tmp);
-    }
   }
   return result;
 }
 
 bool mg_file_printf(struct mg_fs *fs, const char *path, const char *fmt, ...) {
-  char tmp[256], *buf = tmp;
-  bool result;
-  size_t len;
   va_list ap;
+  char *data;
+  bool result = false;
   va_start(ap, fmt);
-  len = mg_vasprintf(&buf, sizeof(tmp), fmt, ap);
+  data = mg_vmprintf(fmt, &ap);
   va_end(ap);
-  result = mg_file_write(fs, path, buf, len > 0 ? (size_t) len : 0);
-  if (buf != tmp) free(buf);
+  result = mg_file_write(fs, path, data, strlen(data));
+  free(data);
   return result;
 }
 
@@ -2734,20 +2693,22 @@ long mg_json_get_long(struct mg_str json, const char *path, long dflt) {
 
 
 
-static void default_logger(unsigned char c) {
+static void default_logger(char c, void *param) {
   putchar(c);
-  (void) c;
+  (void) c, (void) param;
 }
 
 static int s_level = MG_LL_INFO;
-static void (*s_log_func)(unsigned char) = default_logger;
+static mg_pfn_t s_log_func = default_logger;
+static void *s_log_func_param = NULL;
 
-void mg_log_set_fn(void (*fn)(unsigned char)) {
+void mg_log_set_fn(mg_pfn_t fn, void *param) {
   s_log_func = fn;
+  s_log_func_param = param;
 }
 
 static void logc(unsigned char c) {
-  s_log_func(c);
+  s_log_func((char) c, s_log_func_param);
 }
 
 static void logs(const char *buf, size_t len) {
@@ -2778,15 +2739,11 @@ bool mg_log_prefix(int level, const char *file, int line, const char *fname) {
 }
 
 void mg_log(const char *fmt, ...) {
-  char mem[256], *buf = mem;
   va_list ap;
-  size_t len;
   va_start(ap, fmt);
-  len = mg_vasprintf(&buf, sizeof(mem), fmt, ap);
+  mg_vrprintf(s_log_func, s_log_func_param, fmt, &ap);
   va_end(ap);
-  logs(buf, len);
   logc((unsigned char) '\n');
-  if (buf != mem) free(buf);
 }
 
 static unsigned char nibble(unsigned c) {
@@ -5238,11 +5195,9 @@ void mg_tls_init(struct mg_connection *c, const struct mg_tls_opts *opts) {
     mbedtls_ssl_conf_ca_chain(&tls->conf, &tls->ca, NULL);
 #endif
     if (opts->srvname.len > 0) {
-      char mem[128], *buf = mem;
-      mg_asprintf(&buf, sizeof(mem), "%.*s", (int) opts->srvname.len,
-                  opts->srvname.ptr);
-      mbedtls_ssl_set_hostname(&tls->ssl, buf);
-      if (buf != mem) free(buf);
+      char *x = mg_mprintf("%.*s", (int) opts->srvname.len, opts->srvname.ptr);
+      mbedtls_ssl_set_hostname(&tls->ssl, x);
+      free(x);
     }
     mbedtls_ssl_conf_authmode(&tls->conf, MBEDTLS_SSL_VERIFY_REQUIRED);
   }
@@ -5396,22 +5351,11 @@ void mg_tls_init(struct mg_connection *c, const struct mg_tls_opts *opts) {
 #endif
     }
   }
-#if OPENSSL_VERSION_NUMBER > 0x10002000L
-  if (opts->srvname.len > 0) {
-    char mem[128], *buf = mem;
-    mg_asprintf(&buf, sizeof(mem), "%.*s", (int) opts->srvname.len,
-                opts->srvname.ptr);
-    SSL_set1_host(tls->ssl, buf);
-    if (buf != mem) free(buf);
-  }
-#endif
   if (opts->ciphers != NULL) SSL_set_cipher_list(tls->ssl, opts->ciphers);
   if (opts->srvname.len > 0) {
-    char mem[128], *buf = mem;
-    mg_asprintf(&buf, sizeof(mem), "%.*s", (int) opts->srvname.len,
-                opts->srvname.ptr);
-    SSL_set_tlsext_host_name(tls->ssl, buf);
-    if (buf != mem) free(buf);
+    char *s = mg_mprintf("%.*s", (int) opts->srvname.len, opts->srvname.ptr);
+    SSL_set1_host(tls->ssl, s);
+    free(s);
   }
   c->tls = tls;
   c->is_tls = 1;
@@ -5726,10 +5670,9 @@ size_t mg_ws_printf(struct mg_connection *c, int op, const char *fmt, ...) {
 
 static void ws_handshake(struct mg_connection *c, const struct mg_str *wskey,
                          const struct mg_str *wsproto, const char *fmt,
-                         va_list ap) {
+                         va_list *ap) {
   const char *magic = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
   unsigned char sha[20], b64_sha[30];
-  char mem[128], *buf = mem;
 
   mg_sha1_ctx sha_ctx;
   mg_sha1_init(&sha_ctx);
@@ -5737,16 +5680,13 @@ static void ws_handshake(struct mg_connection *c, const struct mg_str *wskey,
   mg_sha1_update(&sha_ctx, (unsigned char *) magic, 36);
   mg_sha1_final(sha, &sha_ctx);
   mg_base64_encode(sha, sizeof(sha), (char *) b64_sha);
-  buf[0] = '\0';
-  if (fmt != NULL) mg_vasprintf(&buf, sizeof(mem), fmt, ap);
-  mg_printf(c,
-            "HTTP/1.1 101 Switching Protocols\r\n"
-            "Upgrade: websocket\r\n"
-            "Connection: Upgrade\r\n"
-            "Sec-WebSocket-Accept: %s\r\n"
-            "%s",
-            b64_sha, buf);
-  if (buf != mem) free(buf);
+  mg_rprintf(mg_pfn_iobuf, &c->send,
+             "HTTP/1.1 101 Switching Protocols\r\n"
+             "Upgrade: websocket\r\n"
+             "Connection: Upgrade\r\n"
+             "Sec-WebSocket-Accept: %s\r\n",
+             b64_sha);
+  if (fmt != NULL) mg_vrprintf(mg_pfn_iobuf, &c->send, fmt, ap);
   if (wsproto != NULL) {
     mg_printf(c, "Sec-WebSocket-Protocol: %.*s\r\n", (int) wsproto->len,
               wsproto->ptr);
@@ -5966,7 +5906,7 @@ void mg_ws_upgrade(struct mg_connection *c, struct mg_http_message *hm,
     struct mg_str *wsproto = mg_http_get_header(hm, "Sec-WebSocket-Protocol");
     va_list ap;
     va_start(ap, fmt);
-    ws_handshake(c, wskey, wsproto, fmt, ap);
+    ws_handshake(c, wskey, wsproto, fmt, &ap);
     va_end(ap);
     c->is_websocket = 1;
     mg_call(c, MG_EV_WS_OPEN, hm);
diff --git a/mongoose.h b/mongoose.h
index 14791527..2cf9349d 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -795,10 +795,9 @@ size_t mg_vrprintf(void (*)(char, void *), void *, const char *fmt, va_list *);
 size_t mg_rprintf(void (*fn)(char, void *), void *, const char *fmt, ...);
 size_t mg_vsnprintf(char *buf, size_t len, const char *fmt, va_list *ap);
 size_t mg_snprintf(char *, size_t, const char *fmt, ...);
-size_t mg_asprintf(char **, size_t, const char *fmt, ...);
-size_t mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap);
+char *mg_vmprintf(const char *fmt, va_list *ap);
 char *mg_mprintf(const char *fmt, ...);
-char *mg_vmprintf(const char *fmt, va_list ap);
+
 
 
 
@@ -809,7 +808,7 @@ void mg_log(const char *fmt, ...);
 bool mg_log_prefix(int ll, const char *file, int line, const char *fname);
 void mg_log_set(int log_level);
 void mg_hexdump(const void *buf, size_t len);
-void mg_log_set_fn(void (*logfunc)(unsigned char ch));
+void mg_log_set_fn(mg_pfn_t fn, void *param);
 
 #if MG_ENABLE_LOG
 #define MG_LOG(level, args)                                                \
diff --git a/src/event.c b/src/event.c
index f8fefa23..fd5e2432 100644
--- a/src/event.c
+++ b/src/event.c
@@ -12,13 +12,12 @@ void mg_call(struct mg_connection *c, int ev, void *ev_data) {
 }
 
 void mg_error(struct mg_connection *c, const char *fmt, ...) {
-  char mem[256], *buf = mem;
+  char buf[64];
   va_list ap;
   va_start(ap, fmt);
-  mg_vasprintf(&buf, sizeof(mem), fmt, ap);
+  mg_vsnprintf(buf, sizeof(buf), fmt, &ap);
   va_end(ap);
   MG_ERROR(("%lu %p %s", c->id, c->fd, buf));
   c->is_closing = 1;             // Set is_closing before sending MG_EV_CALL
   mg_call(c, MG_EV_ERROR, buf);  // Let user handler to override it
-  if (buf != mem) free(buf);
 }
diff --git a/src/fmt.c b/src/fmt.c
index fe7407ee..121df2fc 100644
--- a/src/fmt.c
+++ b/src/fmt.c
@@ -1,37 +1,6 @@
 #include "fmt.h"
 #include "iobuf.h"
 
-size_t mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap) {
-  va_list ap_copy;
-  size_t len;
-
-  va_copy(ap_copy, ap);
-  len = mg_vsnprintf(*buf, size, fmt, &ap_copy);
-  va_end(ap_copy);
-
-  if (len >= size) {
-    //  Allocate a buffer that is large enough
-    if ((*buf = (char *) calloc(1, len + 1)) == NULL) {
-      len = 0;
-    } else {
-      va_copy(ap_copy, ap);
-      len = mg_vsnprintf(*buf, len + 1, fmt, &ap_copy);
-      va_end(ap_copy);
-    }
-  }
-
-  return len;
-}
-
-size_t mg_asprintf(char **buf, size_t size, const char *fmt, ...) {
-  size_t ret;
-  va_list ap;
-  va_start(ap, fmt);
-  ret = mg_vasprintf(buf, size, fmt, ap);
-  va_end(ap);
-  return ret;
-}
-
 size_t mg_snprintf(char *buf, size_t len, const char *fmt, ...) {
   va_list ap;
   size_t n;
@@ -41,17 +10,17 @@ size_t mg_snprintf(char *buf, size_t len, const char *fmt, ...) {
   return n;
 }
 
-char *mg_vmprintf(const char *fmt, va_list ap) {
-  char *s = NULL;
-  mg_vasprintf(&s, 0, fmt, ap);
-  return s;
+char *mg_vmprintf(const char *fmt, va_list *ap) {
+  struct mg_iobuf io = {0, 0, 0, 256};
+  mg_vrprintf(mg_pfn_iobuf, &io, fmt, ap);
+  return (char *) io.buf;
 }
 
 char *mg_mprintf(const char *fmt, ...) {
-  char *s = NULL;
+  char *s;
   va_list ap;
   va_start(ap, fmt);
-  mg_vasprintf(&s, 0, fmt, ap);
+  s = mg_vmprintf(fmt, &ap);
   va_end(ap);
   return s;
 }
diff --git a/src/fmt.h b/src/fmt.h
index 12d7ac9b..b41ad67c 100644
--- a/src/fmt.h
+++ b/src/fmt.h
@@ -15,7 +15,5 @@ size_t mg_vrprintf(void (*)(char, void *), void *, const char *fmt, va_list *);
 size_t mg_rprintf(void (*fn)(char, void *), void *, const char *fmt, ...);
 size_t mg_vsnprintf(char *buf, size_t len, const char *fmt, va_list *ap);
 size_t mg_snprintf(char *, size_t, const char *fmt, ...);
-size_t mg_asprintf(char **, size_t, const char *fmt, ...);
-size_t mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap);
+char *mg_vmprintf(const char *fmt, va_list *ap);
 char *mg_mprintf(const char *fmt, ...);
-char *mg_vmprintf(const char *fmt, va_list ap);
diff --git a/src/fs.c b/src/fs.c
index 0d5e070c..04838dff 100644
--- a/src/fs.c
+++ b/src/fs.c
@@ -45,31 +45,22 @@ char *mg_file_read(struct mg_fs *fs, const char *path, size_t *sizep) {
 bool mg_file_write(struct mg_fs *fs, const char *path, const void *buf,
                    size_t len) {
   bool result = false;
-  struct mg_fd *fd;
-  char tmp[MG_PATH_MAX];
-  mg_snprintf(tmp, sizeof(tmp), "%s..%d", path, rand());
-  if ((fd = mg_fs_open(fs, tmp, MG_FS_WRITE)) != NULL) {
+  struct mg_fd *fd = mg_fs_open(fs, path, MG_FS_WRITE);
+  if (fd != NULL) {
     result = fs->wr(fd->fd, buf, len) == len;
     mg_fs_close(fd);
-    if (result) {
-      fs->rm(path);
-      fs->mv(tmp, path);
-    } else {
-      fs->rm(tmp);
-    }
   }
   return result;
 }
 
 bool mg_file_printf(struct mg_fs *fs, const char *path, const char *fmt, ...) {
-  char tmp[256], *buf = tmp;
-  bool result;
-  size_t len;
   va_list ap;
+  char *data;
+  bool result = false;
   va_start(ap, fmt);
-  len = mg_vasprintf(&buf, sizeof(tmp), fmt, ap);
+  data = mg_vmprintf(fmt, &ap);
   va_end(ap);
-  result = mg_file_write(fs, path, buf, len > 0 ? (size_t) len : 0);
-  if (buf != tmp) free(buf);
+  result = mg_file_write(fs, path, data, strlen(data));
+  free(data);
   return result;
 }
diff --git a/src/log.c b/src/log.c
index 1abd8da0..295bb962 100644
--- a/src/log.c
+++ b/src/log.c
@@ -3,20 +3,22 @@
 #include "str.h"
 #include "util.h"
 
-static void default_logger(unsigned char c) {
+static void default_logger(char c, void *param) {
   putchar(c);
-  (void) c;
+  (void) c, (void) param;
 }
 
 static int s_level = MG_LL_INFO;
-static void (*s_log_func)(unsigned char) = default_logger;
+static mg_pfn_t s_log_func = default_logger;
+static void *s_log_func_param = NULL;
 
-void mg_log_set_fn(void (*fn)(unsigned char)) {
+void mg_log_set_fn(mg_pfn_t fn, void *param) {
   s_log_func = fn;
+  s_log_func_param = param;
 }
 
 static void logc(unsigned char c) {
-  s_log_func(c);
+  s_log_func((char) c, s_log_func_param);
 }
 
 static void logs(const char *buf, size_t len) {
@@ -47,15 +49,11 @@ bool mg_log_prefix(int level, const char *file, int line, const char *fname) {
 }
 
 void mg_log(const char *fmt, ...) {
-  char mem[256], *buf = mem;
   va_list ap;
-  size_t len;
   va_start(ap, fmt);
-  len = mg_vasprintf(&buf, sizeof(mem), fmt, ap);
+  mg_vrprintf(s_log_func, s_log_func_param, fmt, &ap);
   va_end(ap);
-  logs(buf, len);
   logc((unsigned char) '\n');
-  if (buf != mem) free(buf);
 }
 
 static unsigned char nibble(unsigned c) {
diff --git a/src/log.h b/src/log.h
index aa0b203c..e90ba79e 100644
--- a/src/log.h
+++ b/src/log.h
@@ -2,13 +2,14 @@
 
 #include "arch.h"
 #include "config.h"
+#include "fmt.h"
 
 enum { MG_LL_NONE, MG_LL_ERROR, MG_LL_INFO, MG_LL_DEBUG, MG_LL_VERBOSE };
 void mg_log(const char *fmt, ...);
 bool mg_log_prefix(int ll, const char *file, int line, const char *fname);
 void mg_log_set(int log_level);
 void mg_hexdump(const void *buf, size_t len);
-void mg_log_set_fn(void (*logfunc)(unsigned char ch));
+void mg_log_set_fn(mg_pfn_t fn, void *param);
 
 #if MG_ENABLE_LOG
 #define MG_LOG(level, args)                                                \
diff --git a/src/tls_mbed.c b/src/tls_mbed.c
index bd832704..cc77385f 100644
--- a/src/tls_mbed.c
+++ b/src/tls_mbed.c
@@ -145,11 +145,9 @@ void mg_tls_init(struct mg_connection *c, const struct mg_tls_opts *opts) {
     mbedtls_ssl_conf_ca_chain(&tls->conf, &tls->ca, NULL);
 #endif
     if (opts->srvname.len > 0) {
-      char mem[128], *buf = mem;
-      mg_asprintf(&buf, sizeof(mem), "%.*s", (int) opts->srvname.len,
-                  opts->srvname.ptr);
-      mbedtls_ssl_set_hostname(&tls->ssl, buf);
-      if (buf != mem) free(buf);
+      char *x = mg_mprintf("%.*s", (int) opts->srvname.len, opts->srvname.ptr);
+      mbedtls_ssl_set_hostname(&tls->ssl, x);
+      free(x);
     }
     mbedtls_ssl_conf_authmode(&tls->conf, MBEDTLS_SSL_VERIFY_REQUIRED);
   }
diff --git a/src/tls_openssl.c b/src/tls_openssl.c
index 15c992c2..0cdc6414 100644
--- a/src/tls_openssl.c
+++ b/src/tls_openssl.c
@@ -89,22 +89,11 @@ void mg_tls_init(struct mg_connection *c, const struct mg_tls_opts *opts) {
 #endif
     }
   }
-#if OPENSSL_VERSION_NUMBER > 0x10002000L
-  if (opts->srvname.len > 0) {
-    char mem[128], *buf = mem;
-    mg_asprintf(&buf, sizeof(mem), "%.*s", (int) opts->srvname.len,
-                opts->srvname.ptr);
-    SSL_set1_host(tls->ssl, buf);
-    if (buf != mem) free(buf);
-  }
-#endif
   if (opts->ciphers != NULL) SSL_set_cipher_list(tls->ssl, opts->ciphers);
   if (opts->srvname.len > 0) {
-    char mem[128], *buf = mem;
-    mg_asprintf(&buf, sizeof(mem), "%.*s", (int) opts->srvname.len,
-                opts->srvname.ptr);
-    SSL_set_tlsext_host_name(tls->ssl, buf);
-    if (buf != mem) free(buf);
+    char *s = mg_mprintf("%.*s", (int) opts->srvname.len, opts->srvname.ptr);
+    SSL_set1_host(tls->ssl, s);
+    free(s);
   }
   c->tls = tls;
   c->is_tls = 1;
diff --git a/src/ws.c b/src/ws.c
index 7ed19b7b..6a6c6a4e 100644
--- a/src/ws.c
+++ b/src/ws.c
@@ -33,10 +33,9 @@ size_t mg_ws_printf(struct mg_connection *c, int op, const char *fmt, ...) {
 
 static void ws_handshake(struct mg_connection *c, const struct mg_str *wskey,
                          const struct mg_str *wsproto, const char *fmt,
-                         va_list ap) {
+                         va_list *ap) {
   const char *magic = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
   unsigned char sha[20], b64_sha[30];
-  char mem[128], *buf = mem;
 
   mg_sha1_ctx sha_ctx;
   mg_sha1_init(&sha_ctx);
@@ -44,16 +43,13 @@ static void ws_handshake(struct mg_connection *c, const struct mg_str *wskey,
   mg_sha1_update(&sha_ctx, (unsigned char *) magic, 36);
   mg_sha1_final(sha, &sha_ctx);
   mg_base64_encode(sha, sizeof(sha), (char *) b64_sha);
-  buf[0] = '\0';
-  if (fmt != NULL) mg_vasprintf(&buf, sizeof(mem), fmt, ap);
-  mg_printf(c,
-            "HTTP/1.1 101 Switching Protocols\r\n"
-            "Upgrade: websocket\r\n"
-            "Connection: Upgrade\r\n"
-            "Sec-WebSocket-Accept: %s\r\n"
-            "%s",
-            b64_sha, buf);
-  if (buf != mem) free(buf);
+  mg_rprintf(mg_pfn_iobuf, &c->send,
+             "HTTP/1.1 101 Switching Protocols\r\n"
+             "Upgrade: websocket\r\n"
+             "Connection: Upgrade\r\n"
+             "Sec-WebSocket-Accept: %s\r\n",
+             b64_sha);
+  if (fmt != NULL) mg_vrprintf(mg_pfn_iobuf, &c->send, fmt, ap);
   if (wsproto != NULL) {
     mg_printf(c, "Sec-WebSocket-Protocol: %.*s\r\n", (int) wsproto->len,
               wsproto->ptr);
@@ -273,7 +269,7 @@ void mg_ws_upgrade(struct mg_connection *c, struct mg_http_message *hm,
     struct mg_str *wsproto = mg_http_get_header(hm, "Sec-WebSocket-Protocol");
     va_list ap;
     va_start(ap, fmt);
-    ws_handshake(c, wskey, wsproto, fmt, ap);
+    ws_handshake(c, wskey, wsproto, fmt, &ap);
     va_end(ap);
     c->is_websocket = 1;
     mg_call(c, MG_EV_WS_OPEN, hm);
diff --git a/test/unit_test.c b/test/unit_test.c
index 055a27cb..09c1e3be 100644
--- a/test/unit_test.c
+++ b/test/unit_test.c
@@ -1785,13 +1785,9 @@ static void test_util(void) {
   }
 
   {
-    s = buf;
-    mg_asprintf(&s, sizeof(buf), "%3d", 123);
-    ASSERT(s == buf);
-    ASSERT(strcmp(buf, "123") == 0);
-    mg_asprintf(&s, sizeof(buf), "%.*s", 7, "a%40b.c");
-    ASSERT(s == buf);
-    ASSERT(strcmp(buf, "a%40b.c") == 0);
+    s = mg_mprintf("%3d", 123);
+    ASSERT(strcmp(s, "123") == 0);
+    free(s);
   }
 
   ASSERT(mg_to64(mg_str("-9223372036854775809")) == 0);