Fix hex buffer mode and add it to the readme

README.md

@@ -110,14 +110,24 @@ The help prompt lists the available commands.
 Commands (lead with ctrl-b):
   c: print available quick commands
   0-9: load the given quick command (0 is 10)
-  p, 0-9: select a different quick commands page (0 is 10)
+  p: select a different quick commands page
   i: view info/stats
   x: start XModem upload with 128B payloads
   X: start XModem upload with 1024B payloads
+  H: enter/exit hex buffer mode
   h: view this help
   q: quit Bytenuts
 ```
 
+### Hex Buffer Mode
+When the `ctrl+b H` command has been issued for the first time, you will enter hex buffer mode. In this mode, the input buffer is interpreted as a hex string and will be converted to its byte equivalent before it gets sent to the target. Example inputs:
+
+- `746573740d0a` gets sent as `test\r\n`
+- `d0a` gets sent as `\r\n` as it assumed the trailing `0` has been omitted
+- `74657374xd0a` gets sent as `test` since the `xd` byte contains an invalid hex character
+
+Hex buffer mode can be turned off with a second `ctrl+b H`.
+
 ## Quick Commands
 
 You can provide multiple pages of quick commands you can easily load in with `ctrl+b [0-9]` in the files `~/.config/bytenuts/commands<idx>`. Bytenuts will load pages starting from `commands1` until a `commands<idx>` no longer exists. The commands should be newline separated. When a command is loaded, the entire contents of the line is loaded into the input buffer.

src/cheerios.c

@@ -143,25 +143,10 @@ cheerios_stop()
 }
 
 int
-cheerios_input(const char *line)
+cheerios_input(const char *buf, size_t len)
 {
-    size_t line_len = strlen(line);
-
     pthread_mutex_lock(&cheerios.lock);
-
-    if (cheerios.config->echo) {
-        char *line_parsed = calloc(1, line_len + 5 + 1);
-        sprintf(line_parsed, ">> %s\r\n", line);
-        insert_buf(&cheerios.lines, line_parsed, strlen(line_parsed));
-        free(line_parsed);
-    }
-
-    write(cheerios.ser_fd, line, strlen(line));
-    if (cheerios.config->no_crlf)
-        write(cheerios.ser_fd, "\n", 1);
-    else
-        write(cheerios.ser_fd, "\r\n", 2);
-
+    write(cheerios.ser_fd, buf, len);
     pthread_mutex_unlock(&cheerios.lock);
     return 0;
 }

src/cheerios.h

@@ -62,9 +62,8 @@ int cheerios_gofwd(int lines);
 /* stop the thread and release memory */
 int cheerios_stop();
 
-/* send over a line of user input to the output
- * do not terminate with a newline! */
-int cheerios_input(const char *line);
+/* send over a line of user input to the output */
+int cheerios_input(const char *buf, size_t len);
 
 /* output a line only to the terminal for info/prompt purposes
  * do not terminate with a newline! */

src/ingest.c

@@ -378,6 +378,7 @@ ingest_thread(void *arg)
                     "  i: view info/stats\r\n"
                     "  x: start XModem upload with 128B payloads\r\n"
                     "  X: start XModem upload with 1024B payloads\r\n"
+                    "  H: enter/exit hex buffer mode\r\n"
                     "  h: view this help\r\n"
                     "  q: quit Bytenuts\r\n",
                     ingest.config->escape
@@ -429,9 +430,21 @@ mode_normal(int ch)
         return 0;
 
     switch (ch) {
-    case '\n': /* send inputs */
-        if (cheerios_input(ingest.inbuf)) {
-            break;
+    case '\n': { /* send inputs */
+        size_t inlen = strlen(ingest.inbuf);
+        const char *ending;
+
+        if (ingest.config->no_crlf)
+            ending = "\n";
+        else
+            ending = "\r\n";
+
+        cheerios_input(ingest.inbuf, inlen);
+        cheerios_input(ending, strlen(ending));
+        if (ingest.config->echo) {
+            cheerios_insert(">> ", 3);
+            cheerios_insert(ingest.inbuf, inlen);
+            cheerios_insert("\r\n", 2);
         }
 
         /* store in history */
@@ -453,6 +466,7 @@ mode_normal(int ch)
         ingest_refresh();
 
         break;
+    }
     case KEY_UP: /* load in history */
         if (ingest.history_pos == 0) { /* top of history */
             break;
@@ -617,17 +631,46 @@ mode_hex(int ch)
     case '\n': { /* send inputs */
         char hexbuf[sizeof(ingest.inbuf)/2];
         size_t inbuflen = strlen(ingest.inbuf);
+        size_t hexlen = 0;
+        /* assume leading 0 on odd length buffers */
+        if (inbuflen % 2 != 0) {
+            memmove(&ingest.inbuf[1], ingest.inbuf, inbuflen);
+            ingest.inbuf[0] = '0';
+            inbuflen++;
+        }
 
         for (int i = 0; i < inbuflen; i += 2) {
             char tmp = ingest.inbuf[i+2];
+            char *inval;
+            long ch;
+
             ingest.inbuf[i+2] = '\0';
-            hexbuf[i/2] = strtol(&ingest.inbuf[i], NULL, 16);
-            // cheerios_print("HEX 0x%02X (%c)\r\n", hexbuf[i/2], hexbuf[i/2]);
+            ch = strtol(&ingest.inbuf[i], &inval, 16);
             ingest.inbuf[i+2] = tmp;
+
+            /* strtol could not parse a character */
+            if (inval != &ingest.inbuf[i+2])
+                break;
+
+            hexbuf[i/2] = ch;
+            hexlen++;
         }
 
-        if (cheerios_insert(hexbuf, inbuflen/2)) {
-            break;
+        cheerios_input(hexbuf, hexlen);
+        if (ingest.config->echo) {
+            cheerios_insert(">> (hex)\r\n", 10);
+            for (int i = 0; i < hexlen; i++) {
+                if (
+                    i > 0 &&
+                    i != hexlen-1 &&
+                    i % 16 == 0
+                ) {
+                    cheerios_insert("\r\n", 2);
+                }
+                cheerios_insert(&ingest.inbuf[i*2], 2);
+                cheerios_insert(" ", 1);
+            }
+            cheerios_insert("\r\n", 2);
         }
 
         /* store in history */