console-client: Cleanup the escape code
This change fixes a bug where multiple tildes were sent if a user typed
\r~~ This is unlike ssh, which allows nesting of escape sequences by
ensuring that only the second tilde is sent after the command sequence
is issued. This patch fixes the behavior so the console-server only ever
gets \r~ for an issued \r~~
This also prepares the escape sequence handling code for an upcoming
change which allows a user configurable escape sequence in addition to
the default ssh like one.
Change-Id: Iaff04e62fb57fab88d413df2b347809b98f728bb
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/console-client.c b/console-client.c
index 1b53624..57ca206 100644
--- a/console-client.c
+++ b/console-client.c
@@ -34,24 +34,71 @@
PROCESS_EXIT,
};
+enum esc_type {
+ ESC_TYPE_SSH,
+};
+
+struct ssh_esc_state {
+ uint8_t state;
+};
+
struct console_client {
int console_sd;
int fd_in;
int fd_out;
bool is_tty;
struct termios orig_termios;
- int esc_str_pos;
- bool newline;
+ enum esc_type esc_type;
+ union {
+ struct ssh_esc_state ssh;
+ } esc_state;
};
-static const uint8_t esc_str[] = { '~', '.' };
+static enum process_rc process_ssh_tty(
+ struct console_client *client, const uint8_t *buf, size_t len)
+{
+ struct ssh_esc_state *esc_state = &client->esc_state.ssh;
+ const uint8_t *out_buf = buf;
+ int rc;
+
+ for (size_t i = 0; i < len; ++i) {
+ switch (buf[i])
+ {
+ case '.':
+ if (esc_state->state != '~') {
+ esc_state->state = '\0';
+ break;
+ }
+ return PROCESS_EXIT;
+ case '~':
+ if (esc_state->state != '\r') {
+ esc_state->state = '\0';
+ break;
+ }
+ esc_state->state = '~';
+ /* We need to print everything to skip the tilde */
+ rc = write_buf_to_fd(
+ client->console_sd, out_buf, i-(out_buf-buf));
+ if (rc < 0)
+ return PROCESS_ERR;
+ out_buf = &buf[i+1];
+ break;
+ case '\r':
+ esc_state->state = '\r';
+ break;
+ default:
+ esc_state->state = '\0';
+ }
+ }
+
+ rc = write_buf_to_fd(client->console_sd, out_buf, len-(out_buf-buf));
+ return rc < 0 ? PROCESS_ERR : PROCESS_OK;
+}
static enum process_rc process_tty(struct console_client *client)
{
- uint8_t e, buf[4096];
- long i;
+ uint8_t buf[4096];
ssize_t len;
- int rc;
len = read(client->fd_in, buf, sizeof(buf));
if (len < 0)
@@ -59,49 +106,13 @@
if (len == 0)
return PROCESS_EXIT;
- /* check escape sequence status */
- for (i = 0; i < len; i++) {
- /* the escape string is only valid after a newline */
- if (buf[i] == '\r') {
- client->newline = true;
- continue;
- }
-
- if (!client->newline)
- continue;
-
- e = esc_str[client->esc_str_pos];
- if (buf[i] == e) {
- client->esc_str_pos++;
-
- /* have we hit the end of the escape string? */
- if (client->esc_str_pos == ARRAY_SIZE(esc_str)) {
-
- /* flush out any data before the escape */
- if (i > client->esc_str_pos)
- write_buf_to_fd(client->console_sd,
- buf,
- i - client->esc_str_pos);
-
- return PROCESS_EXIT;
- }
- } else {
- /* if we're partially the way through the escape
- * string, flush out the bytes we'd skipped */
- if (client->esc_str_pos)
- write_buf_to_fd(client->console_sd,
- esc_str, client->esc_str_pos);
- client->esc_str_pos = 0;
- client->newline = false;
- }
- }
-
- rc = write_buf_to_fd(client->console_sd, buf,
- len - client->esc_str_pos);
- if (rc < 0)
+ switch (client->esc_type)
+ {
+ case ESC_TYPE_SSH:
+ return process_ssh_tty(client, buf, len);
+ default:
return PROCESS_ERR;
-
- return PROCESS_OK;
+ }
}
@@ -199,6 +210,7 @@
client = &_client;
memset(client, 0, sizeof(*client));
+ client->esc_type = ESC_TYPE_SSH;
rc = client_init(client);
if (rc)