diff options
| -rw-r--r-- | src/mds-kkbd.c | 51 |
1 files changed, 35 insertions, 16 deletions
diff --git a/src/mds-kkbd.c b/src/mds-kkbd.c index dc0356e..3319c87 100644 --- a/src/mds-kkbd.c +++ b/src/mds-kkbd.c @@ -798,7 +798,7 @@ int handle_keyboard_enumeration(const char* recv_modify_id) the buffer. */ fail_if (ensure_send_buffer_size(n + 1) < 0); - /* Fetch and increment local message ID. */ + /* Fetch and increase local message ID. */ with_mutex (send_mutex, msgid = message_id; message_id = message_id == INT32_MAX ? 0 : (message_id + 1); @@ -1307,50 +1307,69 @@ static int remap(char* table, size_t n) * @param recv_message_id The value of the `Message ID`-header * @return Zero on success, -1 on error */ -static int mapping_query(const char* recv_client_id, const char* recv_message_id) /* TODO proofread */ +static int mapping_query(const char* recv_client_id, const char* recv_message_id) { size_t top = 64 + 3 * sizeof(size_t), n = 0, off, i; - int greatest = (int)mapping_size, r; + ssize_t len; + int greatest = 0, r; uint32_t msgid; + /* Count the number of non-identity mappings, and + figure out the value of non-identity mapping + with the highest value. */ for (i = 0; i < mapping_size; i++) if (mapping[i] != (int)i) { greatest = max(greatest, mapping[i]); n++; } - - n *= 3 + (size_t)(greatest > 0x00FF ? 5 : 3); - + /* If the highest source is larger than the + highest targt, that source value will + be highest integer that will be included + the mapping-table. */ + greatest = max(greatest, (int)mapping_size); + /* Calculate an upper bound for the payload. */ + n *= 2 + 2 * (size_t)(greatest > 0x00FF ? 5 : 3); + + /* Ensure that the buffer is large enough for + the message and that `sprintf` will not + write outside it. */ fail_if (ensure_send_buffer_size(top + n + 2) < 0); + /* Fetch and increase local message ID. */ with_mutex (send_mutex, msgid = message_id; message_id = message_id == INT32_MAX ? 0 : (message_id + 1); ); + /* The offset for the payload should fit all + headers and an empty line. */ off = top + 1; + /* Write all non-identity mappings to the payload. */ for (i = 0; i < mapping_size; i++) if (mapping[i] != (int)i) - { - sprintf(send_buffer + off, "%i %i\n", i, mapping[i]); - off += strlen(send_buffer + off); - } - + sprintf(send_buffer + off, "%i %i\n%zn", i, mapping[i], &len), + off += (size_t)len; + /* Calculate the length of the payload. */ n = (size_t)(off - (top + 1)); + /* Write the headers, and the empty line after them. */ sprintf(send_buffer, "To: %s\n" "In response to: %s\n" "Message ID: %" PRIu32 "\n" "Length: %zu\n" - "\n", - recv_client_id, recv_message_id, msgid, n); - - off = top + 1; - off -= top = strlen(send_buffer); + "\n%zn", + recv_client_id, recv_message_id, msgid, n, &len); + top = (size_t)len; + /* Move the headers and the empty line so that they are + juxtaposed with the payload. */ + off -= top; memmove(send_buffer + off, send_buffer, top * sizeof(char)); + + /* Send the message. */ + with_mutex (send_mutex, r = full_send(send_buffer + off, top + n); if (r) r = errno ? errno : -1; |