gdb_server: Log both incoming and outgoing GDB packets

[openocd.git] / src / helper / log.c

/***************************************************************************
 *   Copyright (C) 2005 by Dominic Rath                                    *
 *   Dominic.Rath@gmx.de                                                   *
 *                                                                         *
 *   Copyright (C) 2007-2010 Øyvind Harboe                                 *
 *   oyvind.harboe@zylin.com                                               *
 *                                                                         *
 *   Copyright (C) 2008 by Spencer Oliver                                  *
 *   spen@spen-soft.co.uk                                                  *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
 ***************************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "log.h"
#include "command.h"
#include "replacements.h"
#include "time_support.h"

#include <stdarg.h>

#ifdef _DEBUG_FREE_SPACE_
#ifdef HAVE_MALLOC_H
#include <malloc.h>
#else
#error "malloc.h is required to use --enable-malloc-logging"
#endif
#endif

int debug_level = LOG_LVL_INFO;

static FILE *log_output;
static struct log_callback *log_callbacks;

static int64_t last_time;
static int64_t current_time;

static int64_t start;

static const char * const log_strings[6] = {
        "User : ",
        "Error: ",
        "Warn : ",      /* want a space after each colon, all same width, colons aligned */
        "Info : ",
        "Debug: ",
        "Debug: "
};

static int count;

/* forward the log to the listeners */
static void log_forward(const char *file, unsigned line, const char *function, const char *string)
{
        struct log_callback *cb, *next;
        cb = log_callbacks;
        /* DANGER!!!! the log callback can remove itself!!!! */
        while (cb) {
                next = cb->next;
                cb->fn(cb->priv, file, line, function, string);
                cb = next;
        }
}

/* The log_puts() serves two somewhat different goals:
 *
 * - logging
 * - feeding low-level info to the user in GDB or Telnet
 *
 * The latter dictates that strings without newline are not logged, lest there
 * will be *MANY log lines when sending one char at the time(e.g.
 * target_request.c).
 *
 */
static void log_puts(enum log_levels level,
        const char *file,
        int line,
        const char *function,
        const char *string)
{
        char *f;

        if (!log_output) {
                /* log_init() not called yet; print on stderr */
                fputs(string, stderr);
                fflush(stderr);
                return;
        }

        if (level == LOG_LVL_OUTPUT) {
                /* do not prepend any headers, just print out what we were given and return */
                fputs(string, log_output);
                fflush(log_output);
                return;
        }

        f = strrchr(file, '/');
        if (f != NULL)
                file = f + 1;

        if (strlen(string) > 0) {
                if (debug_level >= LOG_LVL_DEBUG) {
                        /* print with count and time information */
                        int64_t t = timeval_ms() - start;
#ifdef _DEBUG_FREE_SPACE_
                        struct mallinfo info;
                        info = mallinfo();
#endif
                        fprintf(log_output, "%s%d %" PRId64 " %s:%d %s()"
#ifdef _DEBUG_FREE_SPACE_
                                " %d"
#endif
                                ": %s", log_strings[level + 1], count, t, file, line, function,
#ifdef _DEBUG_FREE_SPACE_
                                info.fordblks,
#endif
                                string);
                } else {
                        /* if we are using gdb through pipes then we do not want any output
                         * to the pipe otherwise we get repeated strings */
                        fprintf(log_output, "%s%s",
                                (level > LOG_LVL_USER) ? log_strings[level + 1] : "", string);
                }
        } else {
                /* Empty strings are sent to log callbacks to keep e.g. gdbserver alive, here we do
                 *nothing. */
        }

        fflush(log_output);

        /* Never forward LOG_LVL_DEBUG, too verbose and they can be found in the log if need be */
        if (level <= LOG_LVL_INFO)
                log_forward(file, line, function, string);
}

void log_printf(enum log_levels level,
        const char *file,
        unsigned line,
        const char *function,
        const char *format,
        ...)
{
        char *string;
        va_list ap;

        count++;
        if (level > debug_level)
                return;

        va_start(ap, format);

        string = alloc_vprintf(format, ap);
        if (string != NULL) {
                log_puts(level, file, line, function, string);
                free(string);
        }

        va_end(ap);
}

void log_vprintf_lf(enum log_levels level, const char *file, unsigned line,
                const char *function, const char *format, va_list args)
{
        char *tmp;

        count++;

        if (level > debug_level)
                return;

        tmp = alloc_vprintf(format, args);

        if (!tmp)
                return;

        /*
         * Note: alloc_vprintf() guarantees that the buffer is at least one
         * character longer.
         */
        strcat(tmp, "\n");
        log_puts(level, file, line, function, tmp);
        free(tmp);
}

void log_printf_lf(enum log_levels level,
        const char *file,
        unsigned line,
        const char *function,
        const char *format,
        ...)
{
        va_list ap;

        va_start(ap, format);
        log_vprintf_lf(level, file, line, function, format, ap);
        va_end(ap);
}

COMMAND_HANDLER(handle_debug_level_command)
{
        if (CMD_ARGC == 1) {
                int new_level;
                COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], new_level);
                if ((new_level > LOG_LVL_DEBUG_IO) || (new_level < LOG_LVL_SILENT)) {
                        LOG_ERROR("level must be between %d and %d", LOG_LVL_SILENT, LOG_LVL_DEBUG_IO);
                        return ERROR_COMMAND_SYNTAX_ERROR;
                }
                debug_level = new_level;
        } else if (CMD_ARGC > 1)
                return ERROR_COMMAND_SYNTAX_ERROR;

        command_print(CMD, "debug_level: %i", debug_level);

        return ERROR_OK;
}

COMMAND_HANDLER(handle_log_output_command)
{
        if (CMD_ARGC == 0 || (CMD_ARGC == 1 && strcmp(CMD_ARGV[0], "default") == 0)) {
                if (log_output != stderr && log_output != NULL) {
                        /* Close previous log file, if it was open and wasn't stderr. */
                        fclose(log_output);
                }
                log_output = stderr;
                LOG_DEBUG("set log_output to default");
                return ERROR_OK;
        }
        if (CMD_ARGC == 1) {
                FILE *file = fopen(CMD_ARGV[0], "w");
                if (file == NULL) {
                        LOG_ERROR("failed to open output log '%s'", CMD_ARGV[0]);
                        return ERROR_FAIL;
                }
                if (log_output != stderr && log_output != NULL) {
                        /* Close previous log file, if it was open and wasn't stderr. */
                        fclose(log_output);
                }
                log_output = file;
                LOG_DEBUG("set log_output to \"%s\"", CMD_ARGV[0]);
                return ERROR_OK;
        }

        return ERROR_COMMAND_SYNTAX_ERROR;
}

static const struct command_registration log_command_handlers[] = {
        {
                .name = "log_output",
                .handler = handle_log_output_command,
                .mode = COMMAND_ANY,
                .help = "redirect logging to a file (default: stderr)",
                .usage = "[file_name | \"default\"]",
        },
        {
                .name = "debug_level",
                .handler = handle_debug_level_command,
                .mode = COMMAND_ANY,
                .help = "Sets the verbosity level of debugging output. "
                        "0 shows errors only; 1 adds warnings; "
                        "2 (default) adds other info; 3 adds debugging; "
                        "4 adds extra verbose debugging.",
                .usage = "number",
        },
        COMMAND_REGISTRATION_DONE
};

int log_register_commands(struct command_context *cmd_ctx)
{
        return register_commands(cmd_ctx, NULL, log_command_handlers);
}

void log_init(void)
{
        /* set defaults for daemon configuration,
         * if not set by cmdline or cfgfile */
        char *debug_env = getenv("OPENOCD_DEBUG_LEVEL");
        if (NULL != debug_env) {
                int value;
                int retval = parse_int(debug_env, &value);
                if (ERROR_OK == retval &&
                                debug_level >= LOG_LVL_SILENT &&
                                debug_level <= LOG_LVL_DEBUG_IO)
                                debug_level = value;
        }

        if (log_output == NULL)
                log_output = stderr;

        start = last_time = timeval_ms();
}

int set_log_output(struct command_context *cmd_ctx, FILE *output)
{
        log_output = output;
        return ERROR_OK;
}

/* add/remove log callback handler */
int log_add_callback(log_callback_fn fn, void *priv)
{
        struct log_callback *cb;

        /* prevent the same callback to be registered more than once, just for sure */
        for (cb = log_callbacks; cb; cb = cb->next) {
                if (cb->fn == fn && cb->priv == priv)
                        return ERROR_COMMAND_SYNTAX_ERROR;
        }

        /* alloc memory, it is safe just to return in case of an error, no need for the caller to
         *check this */
        cb = malloc(sizeof(struct log_callback));
        if (cb == NULL)
                return ERROR_BUF_TOO_SMALL;

        /* add item to the beginning of the linked list */
        cb->fn = fn;
        cb->priv = priv;
        cb->next = log_callbacks;
        log_callbacks = cb;

        return ERROR_OK;
}

int log_remove_callback(log_callback_fn fn, void *priv)
{
        struct log_callback *cb, **p;

        for (p = &log_callbacks; (cb = *p); p = &(*p)->next) {
                if (cb->fn == fn && cb->priv == priv) {
                        *p = cb->next;
                        free(cb);
                        return ERROR_OK;
                }
        }

        /* no such item */
        return ERROR_COMMAND_SYNTAX_ERROR;
}

/* return allocated string w/printf() result */
char *alloc_vprintf(const char *fmt, va_list ap)
{
        va_list ap_copy;
        int len;
        char *string;

        /* determine the length of the buffer needed */
        va_copy(ap_copy, ap);
        len = vsnprintf(NULL, 0, fmt, ap_copy);
        va_end(ap_copy);

        /* allocate and make room for terminating zero. */
        /* FIXME: The old version always allocated at least one byte extra and
         * other code depend on that. They should be probably be fixed, but for
         * now reserve the extra byte. */
        string = malloc(len + 2);
        if (string == NULL)
                return NULL;

        /* do the real work */
        vsnprintf(string, len + 1, fmt, ap);

        return string;
}

char *alloc_printf(const char *format, ...)
{
        char *string;
        va_list ap;
        va_start(ap, format);
        string = alloc_vprintf(format, ap);
        va_end(ap);
        return string;
}

/* Code must return to the server loop before 1000ms has returned or invoke
 * this function.
 *
 * The GDB connection will time out if it spends >2000ms and you'll get nasty
 * error messages from GDB:
 *
 * Ignoring packet error, continuing...
 * Reply contains invalid hex digit 116
 *
 * While it is possible use "set remotetimeout" to more than the default 2000ms
 * in GDB, OpenOCD guarantees that it sends keep-alive packages on the
 * GDB protocol and it is a bug in OpenOCD not to either return to the server
 * loop or invoke keep_alive() every 1000ms.
 *
 * This function will send a keep alive packet if >500ms has passed since last time
 * it was invoked.
 *
 * Note that this function can be invoked often, so it needs to be relatively
 * fast when invoked more often than every 500ms.
 *
 */
#define KEEP_ALIVE_KICK_TIME_MS  500
#define KEEP_ALIVE_TIMEOUT_MS   1000

static void gdb_timeout_warning(int64_t delta_time)
{
        extern int gdb_actual_connections;

        if (gdb_actual_connections)
                LOG_WARNING("keep_alive() was not invoked in the "
                        "%d ms timelimit. GDB alive packet not "
                        "sent! (%" PRId64 " ms). Workaround: increase "
                        "\"set remotetimeout\" in GDB",
                        KEEP_ALIVE_TIMEOUT_MS,
                        delta_time);
        else
                LOG_DEBUG("keep_alive() was not invoked in the "
                        "%d ms timelimit (%" PRId64 " ms). This may cause "
                        "trouble with GDB connections.",
                        KEEP_ALIVE_TIMEOUT_MS,
                        delta_time);
}

void keep_alive(void)
{
        current_time = timeval_ms();

        int64_t delta_time = current_time - last_time;

        if (delta_time > KEEP_ALIVE_TIMEOUT_MS) {
                last_time = current_time;

                gdb_timeout_warning(delta_time);
        }

        if (delta_time > KEEP_ALIVE_KICK_TIME_MS) {
                last_time = current_time;

                /* this will keep the GDB connection alive */
                LOG_USER_N("%s", "");

                /* DANGER!!!! do not add code to invoke e.g. target event processing,
                 * jim timer processing, etc. it can cause infinite recursion +
                 * jim event callbacks need to happen at a well defined time,
                 * not anywhere keep_alive() is invoked.
                 *
                 * These functions should be invoked at a well defined spot in server.c
                 */
        }
}

/* reset keep alive timer without sending message */
void kept_alive(void)
{
        current_time = timeval_ms();

        int64_t delta_time = current_time - last_time;

        last_time = current_time;

        if (delta_time > KEEP_ALIVE_TIMEOUT_MS)
                gdb_timeout_warning(delta_time);
}

/* if we sleep for extended periods of time, we must invoke keep_alive() intermittently */
void alive_sleep(uint64_t ms)
{
        uint64_t napTime = 10;
        for (uint64_t i = 0; i < ms; i += napTime) {
                uint64_t sleep_a_bit = ms - i;
                if (sleep_a_bit > napTime)
                        sleep_a_bit = napTime;

                usleep(sleep_a_bit * 1000);
                keep_alive();
        }
}

void busy_sleep(uint64_t ms)
{
        uint64_t then = timeval_ms();
        while (timeval_ms() - then < ms) {
                /*
                 * busy wait
                 */
        }
}

/* Maximum size of socket error message retrieved from operation system */
#define MAX_SOCKET_ERR_MSG_LENGTH 256

/* Provide log message for the last socket error.
   Uses errno on *nix and WSAGetLastError() on Windows */
void log_socket_error(const char *socket_desc)
{
        int error_code;
#ifdef _WIN32
        error_code = WSAGetLastError();
        char error_message[MAX_SOCKET_ERR_MSG_LENGTH];
        error_message[0] = '\0';
        DWORD retval = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, error_code, 0,
                error_message, MAX_SOCKET_ERR_MSG_LENGTH, NULL);
        error_message[MAX_SOCKET_ERR_MSG_LENGTH - 1] = '\0';
        const bool have_message = (retval != 0) && (error_message[0] != '\0');
        LOG_ERROR("Error on socket '%s': WSAGetLastError==%d%s%s.", socket_desc, error_code,
                (have_message ? ", message: " : ""),
                (have_message ? error_message : ""));
#else
        error_code = errno;
        LOG_ERROR("Error on socket '%s': errno==%d, message: %s.", socket_desc, error_code, strerror(error_code));
#endif
}

/**
 * Find the first non-printable character in the char buffer, return a pointer to it.
 * If no such character exists, return NULL.
 */
char *find_nonprint_char(char *buf, unsigned buf_len)
{
        for (unsigned int i = 0; i < buf_len; i++) {
                if (!isprint(buf[i]))
                        return buf + i;
        }
        return NULL;
}