diff options
Diffstat (limited to 'net/tipc/log.c')
-rw-r--r-- | net/tipc/log.c | 302 |
1 files changed, 10 insertions, 292 deletions
diff --git a/net/tipc/log.c b/net/tipc/log.c index 026733f2491..abef644f27d 100644 --- a/net/tipc/log.c +++ b/net/tipc/log.c @@ -36,302 +36,20 @@ #include "core.h" #include "config.h" -#include "log.h" - -/* - * TIPC pre-defines the following print buffers: - * - * TIPC_NULL : null buffer (i.e. print nowhere) - * TIPC_CONS : system console - * TIPC_LOG : TIPC log buffer - * - * Additional user-defined print buffers are also permitted. - */ -static struct print_buf null_buf = { NULL, 0, NULL, 0 }; -struct print_buf *const TIPC_NULL = &null_buf; - -static struct print_buf cons_buf = { NULL, 0, NULL, 1 }; -struct print_buf *const TIPC_CONS = &cons_buf; - -static struct print_buf log_buf = { NULL, 0, NULL, 1 }; -struct print_buf *const TIPC_LOG = &log_buf; - -/* - * Locking policy when using print buffers. - * - * 1) tipc_printf() uses 'print_lock' to protect against concurrent access to - * 'print_string' when writing to a print buffer. This also protects against - * concurrent writes to the print buffer being written to. - * - * 2) tipc_log_XXX() leverages the aforementioned use of 'print_lock' to - * protect against all types of concurrent operations on their associated - * print buffer (not just write operations). - * - * Note: All routines of the form tipc_printbuf_XXX() are lock-free, and rely - * on the caller to prevent simultaneous use of the print buffer(s) being - * manipulated. - */ -static char print_string[TIPC_PB_MAX_STR]; -static DEFINE_SPINLOCK(print_lock); - -static void tipc_printbuf_move(struct print_buf *pb_to, - struct print_buf *pb_from); - -#define FORMAT(PTR, LEN, FMT) \ -{\ - va_list args;\ - va_start(args, FMT);\ - LEN = vsprintf(PTR, FMT, args);\ - va_end(args);\ - *(PTR + LEN) = '\0';\ -} - -/** - * tipc_printbuf_init - initialize print buffer to empty - * @pb: pointer to print buffer structure - * @raw: pointer to character array used by print buffer - * @size: size of character array - * - * Note: If the character array is too small (or absent), the print buffer - * becomes a null device that discards anything written to it. - */ -void tipc_printbuf_init(struct print_buf *pb, char *raw, u32 size) -{ - pb->buf = raw; - pb->crs = raw; - pb->size = size; - pb->echo = 0; - - if (size < TIPC_PB_MIN_SIZE) { - pb->buf = NULL; - } else if (raw) { - pb->buf[0] = 0; - pb->buf[size - 1] = ~0; - } -} - -/** - * tipc_printbuf_reset - reinitialize print buffer to empty state - * @pb: pointer to print buffer structure - */ -static void tipc_printbuf_reset(struct print_buf *pb) -{ - if (pb->buf) { - pb->crs = pb->buf; - pb->buf[0] = 0; - pb->buf[pb->size - 1] = ~0; - } -} - -/** - * tipc_printbuf_empty - test if print buffer is in empty state - * @pb: pointer to print buffer structure - * - * Returns non-zero if print buffer is empty. - */ -static int tipc_printbuf_empty(struct print_buf *pb) -{ - return !pb->buf || (pb->crs == pb->buf); -} - -/** - * tipc_printbuf_validate - check for print buffer overflow - * @pb: pointer to print buffer structure - * - * Verifies that a print buffer has captured all data written to it. - * If data has been lost, linearize buffer and prepend an error message - * - * Returns length of print buffer data string (including trailing NUL) - */ -int tipc_printbuf_validate(struct print_buf *pb) -{ - char *err = "\n\n*** PRINT BUFFER OVERFLOW ***\n\n"; - char *cp_buf; - struct print_buf cb; - - if (!pb->buf) - return 0; - - if (pb->buf[pb->size - 1] == 0) { - cp_buf = kmalloc(pb->size, GFP_ATOMIC); - if (cp_buf) { - tipc_printbuf_init(&cb, cp_buf, pb->size); - tipc_printbuf_move(&cb, pb); - tipc_printbuf_move(pb, &cb); - kfree(cp_buf); - memcpy(pb->buf, err, strlen(err)); - } else { - tipc_printbuf_reset(pb); - tipc_printf(pb, err); - } - } - return pb->crs - pb->buf + 1; -} - -/** - * tipc_printbuf_move - move print buffer contents to another print buffer - * @pb_to: pointer to destination print buffer structure - * @pb_from: pointer to source print buffer structure - * - * Current contents of destination print buffer (if any) are discarded. - * Source print buffer becomes empty if a successful move occurs. - */ -static void tipc_printbuf_move(struct print_buf *pb_to, - struct print_buf *pb_from) -{ - int len; - - /* Handle the cases where contents can't be moved */ - if (!pb_to->buf) - return; - - if (!pb_from->buf) { - tipc_printbuf_reset(pb_to); - return; - } - - if (pb_to->size < pb_from->size) { - strcpy(pb_to->buf, "*** PRINT BUFFER MOVE ERROR ***"); - pb_to->buf[pb_to->size - 1] = ~0; - pb_to->crs = strchr(pb_to->buf, 0); - return; - } - - /* Copy data from char after cursor to end (if used) */ - len = pb_from->buf + pb_from->size - pb_from->crs - 2; - if ((pb_from->buf[pb_from->size - 1] == 0) && (len > 0)) { - strcpy(pb_to->buf, pb_from->crs + 1); - pb_to->crs = pb_to->buf + len; - } else - pb_to->crs = pb_to->buf; - - /* Copy data from start to cursor (always) */ - len = pb_from->crs - pb_from->buf; - strcpy(pb_to->crs, pb_from->buf); - pb_to->crs += len; - - tipc_printbuf_reset(pb_from); -} /** - * tipc_printf - append formatted output to print buffer - * @pb: pointer to print buffer + * tipc_snprintf - append formatted output to print buffer + * @buf: pointer to print buffer + * @len: buffer length * @fmt: formatted info to be printed */ -void tipc_printf(struct print_buf *pb, const char *fmt, ...) -{ - int chars_to_add; - int chars_left; - char save_char; - - spin_lock_bh(&print_lock); - - FORMAT(print_string, chars_to_add, fmt); - if (chars_to_add >= TIPC_PB_MAX_STR) - strcpy(print_string, "*** PRINT BUFFER STRING TOO LONG ***"); - - if (pb->buf) { - chars_left = pb->buf + pb->size - pb->crs - 1; - if (chars_to_add <= chars_left) { - strcpy(pb->crs, print_string); - pb->crs += chars_to_add; - } else if (chars_to_add >= (pb->size - 1)) { - strcpy(pb->buf, print_string + chars_to_add + 1 - - pb->size); - pb->crs = pb->buf + pb->size - 1; - } else { - strcpy(pb->buf, print_string + chars_left); - save_char = print_string[chars_left]; - print_string[chars_left] = 0; - strcpy(pb->crs, print_string); - print_string[chars_left] = save_char; - pb->crs = pb->buf + chars_to_add - chars_left; - } - } - - if (pb->echo) - printk("%s", print_string); - - spin_unlock_bh(&print_lock); -} - -/** - * tipc_log_resize - change the size of the TIPC log buffer - * @log_size: print buffer size to use - */ -int tipc_log_resize(int log_size) -{ - int res = 0; - - spin_lock_bh(&print_lock); - kfree(TIPC_LOG->buf); - TIPC_LOG->buf = NULL; - if (log_size) { - if (log_size < TIPC_PB_MIN_SIZE) - log_size = TIPC_PB_MIN_SIZE; - res = TIPC_LOG->echo; - tipc_printbuf_init(TIPC_LOG, kmalloc(log_size, GFP_ATOMIC), - log_size); - TIPC_LOG->echo = res; - res = !TIPC_LOG->buf; - } - spin_unlock_bh(&print_lock); - - return res; -} - -/** - * tipc_log_resize_cmd - reconfigure size of TIPC log buffer - */ -struct sk_buff *tipc_log_resize_cmd(const void *req_tlv_area, int req_tlv_space) -{ - u32 value; - - if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED)) - return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR); - - value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area)); - if (value > 32768) - return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE - " (log size must be 0-32768)"); - if (tipc_log_resize(value)) - return tipc_cfg_reply_error_string( - "unable to create specified log (log size is now 0)"); - return tipc_cfg_reply_none(); -} - -/** - * tipc_log_dump - capture TIPC log buffer contents in configuration message - */ -struct sk_buff *tipc_log_dump(void) +int tipc_snprintf(char *buf, int len, const char *fmt, ...) { - struct sk_buff *reply; - - spin_lock_bh(&print_lock); - if (!TIPC_LOG->buf) { - spin_unlock_bh(&print_lock); - reply = tipc_cfg_reply_ultra_string("log not activated\n"); - } else if (tipc_printbuf_empty(TIPC_LOG)) { - spin_unlock_bh(&print_lock); - reply = tipc_cfg_reply_ultra_string("log is empty\n"); - } else { - struct tlv_desc *rep_tlv; - struct print_buf pb; - int str_len; + int i; + va_list args; - str_len = min(TIPC_LOG->size, 32768u); - spin_unlock_bh(&print_lock); - reply = tipc_cfg_reply_alloc(TLV_SPACE(str_len)); - if (reply) { - rep_tlv = (struct tlv_desc *)reply->data; - tipc_printbuf_init(&pb, TLV_DATA(rep_tlv), str_len); - spin_lock_bh(&print_lock); - tipc_printbuf_move(&pb, TIPC_LOG); - spin_unlock_bh(&print_lock); - str_len = strlen(TLV_DATA(rep_tlv)) + 1; - skb_put(reply, TLV_SPACE(str_len)); - TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len); - } - } - return reply; + va_start(args, fmt); + i = vscnprintf(buf, len, fmt, args); + va_end(args); + return i; } |