From 4c76ca4c73f047288e0f0c04a5622d3108669854 Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Mon, 24 Aug 2015 16:20:58 +0200 Subject: mds-respawn: typo + mds-kkbd: doc, derp, and minimise some buffer sizes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- src/mds-kkbd.c | 49 +++++++++++++++++++++++++++++++++++++------------ src/mds-respawn.c | 2 +- 2 files changed, 38 insertions(+), 13 deletions(-) diff --git a/src/mds-kkbd.c b/src/mds-kkbd.c index 9d687ce..7c83560 100644 --- a/src/mds-kkbd.c +++ b/src/mds-kkbd.c @@ -77,6 +77,11 @@ # define PRESENT_LEDS "num caps scrl" #endif +/** + * Measure a string literal in compile time + */ +#define lengthof(str) (sizeof(str) / sizeof(char) - 1) + /** @@ -155,7 +160,7 @@ static int scancode_ptr = 0; /** * Message buffer for `send_key` */ -static char key_send_buffer[111]; +static char key_send_buffer[80 + 3 * 3 + 5 + lengthof(KEYBOARD_ID) + 10 + 1]; /** * Message buffer for the main thread @@ -692,7 +697,7 @@ int handle_enumerate_keyboards(const char* recv_client_id, const char* recv_mess message_id = message_id == UINT32_MAX ? 0 : (message_id + 1); ); - fail_if (ensure_send_buffer_size(48 + strlen(recv_modify_id) + 1) < 0); + fail_if (ensure_send_buffer_size(47 + strlen(recv_modify_id) + 1) < 0); sprintf(send_buffer, "Modify: no\n" "Modify ID: %s\n" @@ -714,8 +719,8 @@ int handle_enumerate_keyboards(const char* recv_client_id, const char* recv_mess message_id = message_id == INT32_MAX ? 0 : (message_id + 1); ); - n = 176 + 3 * sizeof(size_t) + strlen(KEYBOARD_ID); - n += strlen(recv_modify_id) + strlen(recv_message_id); + n = 134 + 3 * sizeof(size_t) + lengthof(KEYBOARD_ID); + n += strlen(recv_client_id) + strlen(recv_modify_id) + strlen(recv_message_id); fail_if (ensure_send_buffer_size(n + 1) < 0); sprintf(send_buffer, "Modify: yes\n" @@ -731,7 +736,7 @@ int handle_enumerate_keyboards(const char* recv_client_id, const char* recv_mess "\n" KEYBOARD_ID "\n", recv_modify_id, msgid, - recv_client_id, recv_message_id, strlen(KEYBOARD_ID) + 1, msgid + 1); + recv_client_id, recv_message_id, lengthof(KEYBOARD_ID) + 1, msgid + 1); with_mutex (send_mutex, r = full_send(send_buffer, strlen(send_buffer)); @@ -751,24 +756,38 @@ int handle_enumerate_keyboards(const char* recv_client_id, const char* recv_mess * @param recv_modify_id The value of the `Modify ID`-header, `NULL` if omitted * @return Zero on success, -1 on error */ -int handle_keyboard_enumeration(const char* recv_modify_id) +int handle_keyboard_enumeration(const char* recv_modify_id) /* TODO proofread */ { - size_t i, off, top, n = 1 + strlen(KEYBOARD_ID "\n") + 3 * sizeof(size_t); + size_t i, off, top, n = lengthof(KEYBOARD_ID "\n") + 3 * sizeof(size_t); uint32_t msgid; int r, have_len = 0; if (recv_modify_id == NULL) return eprint("did not get a modify ID, ignoring."), 0; + + /* Calculate length of received message. */ + + /* Measure the length of the headers. */ for (i = 0; i < received.header_count; i++) n += strlen(received.headers[i]); + /* Count the line feeds after the headers. */ n += received.header_count; + /* There is an empty line between headers and payload. */ + n += 1; + /* Add the length of the payload. */ n += received.payload_size; + n += off = 64 + strlen(recv_modify_id) + 3 * sizeof(size_t); + + /* Make sure the buffer fits the message, add one additional + character to the allocation so sprintf does not write outside + the buffer. */ fail_if (ensure_send_buffer_size(n + 1) < 0); + /* Fetch and increment local message ID. */ with_mutex (send_mutex, msgid = message_id; message_id = message_id == INT32_MAX ? 0 : (message_id + 1); @@ -933,7 +952,7 @@ int handle_get_keyboard_leds(const char* recv_client_id, const char* recv_messag message_id = message_id == INT32_MAX ? 0 : (message_id + 1); ); - n = 95 + 3 * sizeof(size_t) + 2 * strlen(PRESENT_LEDS); + n = 65 + 2 * strlen(PRESENT_LEDS); n += strlen(recv_client_id) + strlen(recv_message_id); fail_if (ensure_send_buffer_size(n + 1) < 0); sprintf(send_buffer, @@ -1007,7 +1026,10 @@ static void remap_led(const char* name, const char* position) char c; if (led < 0) - return eprintf("received invalid LED, %s, to remap, ignoring.", name), 0; + { + eprintf("received invalid LED, %s, to remap, ignoring.", name); + return; + } if (pos >= 0) goto done; @@ -1019,7 +1041,10 @@ static void remap_led(const char* name, const char* position) break; if (i < n) - return eprintf("received invalid LED position, %s, ignoring.", position), 0; + { + eprintf("received invalid LED position, %s, ignoring.", position); + return; + } pos = 1 << pos; @@ -1242,7 +1267,7 @@ 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) +static int mapping_query(const char* recv_client_id, const char* recv_message_id) /* TODO proofread */ { size_t top = 64 + 3 * sizeof(size_t), n = 0, off, i; int greatest = (int)mapping_size, r; @@ -1627,7 +1652,7 @@ int fetch_keys(void) */ int send_errno(int error, const char* recv_client_id, const char* recv_message_id) { - size_t n = 79 + strlen(recv_client_id) + strlen(recv_message_id) + 3 * sizeof(int); + size_t n = 69 + strlen(recv_client_id) + strlen(recv_message_id) + 3 * sizeof(int); int r; fail_if (ensure_send_buffer_size(n + 1) < 0); diff --git a/src/mds-respawn.c b/src/mds-respawn.c index 0b68d08..cc1b3be 100644 --- a/src/mds-respawn.c +++ b/src/mds-respawn.c @@ -296,7 +296,7 @@ int postinitialise_server(void) else if (strequals(commands_args[i], "--initial-spawn")) fail_if (xstrdup(commands_args[i], "--respawn")); - /* Respawn dead and dead and buried servers.*/ + /* Respawn dead and dead and buried servers. */ for (i = 0; i < servers; i++) if ((states[i].state == DEAD) || -- cgit v1.2.3-70-g09d2