lirc_log.c

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/****************************************************************************
** lircd.c *****************************************************************
****************************************************************************
*
* lirc_log - simple logging module.
*
*
*/

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif


#include <errno.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <time.h>
#include <pwd.h>
#include <unistd.h>
#include <limits.h>
#include <ctype.h>
#include <syslog.h>

#include "lirc/lirc_log.h"

#ifndef min
#define min(a, b) (a < b ? a : b)
#endif

#define HOSTNAME_LEN 128

static const logchannel_t logchannel = LOG_LIB;

char hostname[HOSTNAME_LEN + 1];
FILE* lf = NULL;

loglevel_t loglevel = LIRC_NOLOG;

logchannel_t logged_channels = LOG_ALL;

static int use_syslog = 1;

const char* syslogident = "lircd-" VERSION;
const char* logfile = "syslog";

char progname[128] = { '?', '\0' };
static int nodaemon = 0;

static const int PRIO_LEN = 16; 
static const char* prio2text(int prio)
{
        switch (prio) {
        case LIRC_DEBUG:        return "Debug";
        case LIRC_NOTICE:       return "Notice";
        case LIRC_INFO:         return "Info";
        case LIRC_WARNING:      return "Warning";
        case LIRC_ERROR:        return "Error";
        case LIRC_TRACE:        return "Trace";
        case LIRC_TRACE1:       return "Trace1";
        case LIRC_TRACE2:       return "Trace2";
        default:                return "(Bad prio)";
        }
}


int lirc_log_use_syslog(void)
{
        return use_syslog;
}


void lirc_log_set_file(const char* s)
{
        if (strcmp(s, "syslog") == 0) {
                use_syslog = 1;
        } else {
                logfile = s;
                use_syslog = 0;
        }
}


int lirc_log_open(const char* _progname, int _nodaemon, loglevel_t level)
{
        strncpy(progname, _progname, sizeof(progname));
        nodaemon = _nodaemon;
        loglevel = level;
        struct passwd* pw;
        const char* user;

        if (use_syslog) {
                if (nodaemon)
                        openlog(syslogident, LOG_CONS | LOG_PID | LOG_PERROR, LOG_LOCAL0);
                else
                        openlog(syslogident, LOG_CONS | LOG_PID, LOG_LOCAL0);
        } else {
                lf = fopen(logfile, "a");
                if (lf == NULL) {
                        fprintf(stderr, "%s: could not open logfile \"%s\"\n",
                                progname, logfile);
                        perror(progname);
                        return 1;
                }
                if (getenv("SUDO_USER") != NULL && geteuid() == 0) {
                        user = getenv("SUDO_USER");
                        user = user == NULL ? "root" : user;
                        pw = getpwnam(user);
                        if (chown(logfile, pw->pw_uid, pw->pw_gid) == -1)
                                perror("Cannot reset log file owner.");
                }
                gethostname(hostname, HOSTNAME_LEN);
                log_warn("------------------------ Log re-opened ----------------------------");
        }
        if (getenv("LIRC_LOGCHANNEL") != NULL) {
                logged_channels = atoi(getenv("LIRC_LOGCHANNEL"));    // FIXME...
        }
        if (level != LIRC_NOLOG) {
                logprintf(level, "%s:  Opening log, level: %s",
                          _progname, prio2text(level));
        }
        return 0;
}


int lirc_log_close(void)
{
        if (use_syslog) {
                closelog();
                return 0;
        } else if (lf) {
                return fclose(lf);
        } else {
                return 0;
        }
}


int lirc_log_reopen(void)
{
        struct stat s;

        if (use_syslog)
                /* Don't need to do anything; this is syslogd's task */
                return 0;

        log_info("closing logfile");
        if (-1 == fstat(fileno(lf), &s)) {
                perror("Invalid logfile!");
                return -1;
        }
        fclose(lf);
        lf = fopen(logfile, "a");
        if (lf == NULL) {
                /* can't print any error messagees */
                perror("Can't open logfile");
                return -1;
        }
        log_info("reopened logfile");
        if (-1 == fchmod(fileno(lf), s.st_mode)) {
                log_warn("could not set file permissions");
                logperror(LIRC_WARNING, NULL);
        }
        return 0;
}


int lirc_log_setlevel(loglevel_t level)
{
        if (level >= LIRC_MIN_LOGLEVEL && level <= LIRC_MAX_LOGLEVEL) {
                loglevel = level;
                return 1;
        } else {
                return 0;
        }
}


static loglevel_t symbol2loglevel(const char* levelstring)
{
        static const struct { const char* label; int value; } options[] = {
                { "TRACE2",  LIRC_TRACE2  },
                { "TRACE1",  LIRC_TRACE1  },
                { "TRACE",   LIRC_TRACE   },
                { "DEBUG",   LIRC_DEBUG   },
                { "INFO",    LIRC_INFO    },
                { "NOTICE",  LIRC_NOTICE  },
                { "WARNING", LIRC_WARNING },
                { "ERROR",   LIRC_ERROR   },
                { 0,         0            }
        };

        char label[128];
        int i;

        if (levelstring == NULL || !*levelstring)
                return LIRC_BADLEVEL;
        for (i = 0; i < sizeof(label) && levelstring[i]; i += 1)
                label[i] = toupper(levelstring[i]);
        label[i] = '\0';
        i = 0;
        while (options[i].label && strcmp(options[i].label, label) != 0)
                i += 1;
        return options[i].label ? options[i].value : -1;
}


loglevel_t lirc_log_defaultlevel(void)
// Try to parse LIRC_LOGLEVEL in environment, fall back to DEFAULT_LOGLEVEL.
{
        loglevel_t try;
        const char* const level = getenv("LIRC_LOGLEVEL");

        if (level != NULL) {
                try = string2loglevel(level);
                return try == LIRC_BADLEVEL ? DEFAULT_LOGLEVEL : try;
        } else {
                return DEFAULT_LOGLEVEL;
        }
}


loglevel_t string2loglevel(const char* s)
{
        long level = LONG_MAX;

        if (s == NULL || *s == '\0')
                return LIRC_BADLEVEL;
        while (isspace(*s) && *s)
                s++;
        if (isdigit(*s)) {
                level = strtol(s, NULL, 10);
                if (level > LIRC_MAX_LOGLEVEL || level < LIRC_MIN_LOGLEVEL)
                        return LIRC_BADLEVEL;
                else
                        return level;
        } else {
                return symbol2loglevel(s);
        }
}


void perrorf(const char* format, ...)
{
        char buff[256];
        va_list ap;

        va_start(ap, format);
        vsnprintf(buff, sizeof(buff), format, ap);
        va_end(ap);
        perror(buff);
}


void logprintf(loglevel_t prio, const char* format_str, ...)
{
        int save_errno = errno;
        va_list ap;
        char buff[PRIO_LEN + strlen(format_str)];

        if (use_syslog) {
                snprintf(buff, sizeof(buff),
                         "%s: %s", prio2text(prio), format_str);
                va_start(ap, format_str);
                vsyslog(min(7, prio), buff, ap);
                va_end(ap);
        } else if (lf) {
                char* currents;
                struct timeval tv;
                struct timezone tz;

                gettimeofday(&tv, &tz);
                currents = ctime(&tv.tv_sec);

                fprintf(lf, "%15.15s.%06ld %s %s: ",
                        currents + 4, (long) tv.tv_usec, hostname, progname);
                fprintf(lf, "%s: ", prio2text(prio));
                va_start(ap, format_str);
                vfprintf(lf, format_str, ap);
                va_end(ap);
                fputc('\n', lf);
                fflush(lf);
        }
        errno = save_errno;
}

void logperror(loglevel_t prio, const char* fmt, ...)
{
        char s[256];
        va_list ap;

        va_start(ap, fmt);
        vsnprintf(s, sizeof(s), fmt, ap);
        va_end(ap);
        if (use_syslog) {
                if (*s != '\0')
                        syslog(min(7, prio), "%s: %m\n", s);
                else
                        syslog(min(7, prio), "%m\n");
        } else {
                if (*s != '\0')
                        logprintf(prio, "%s: %s", s, strerror(errno));
                else
                        logprintf(prio, "%s", strerror(errno));
        }
}


int lirc_log_get_clientlog(const char* basename, char* buffer, ssize_t size)
{
        const char* home;
        struct passwd* pw;
        const char* user;
        int r;

        if (getenv("XDG_CACHE_HOME") != NULL) {
                strncpy(buffer, getenv("XDG_CACHE_HOME"), size);
                buffer[size - 1] = '\0';
        } else if (getenv("SUDO_USER") != NULL && geteuid() == 0) {
                user = getenv("SUDO_USER");
                if (user == NULL)
                        user = "root";
                pw = getpwnam(user);
                snprintf(buffer, size, "%s/.cache", pw->pw_dir);
        } else {
                home = getenv("HOME");
                home = home != NULL ? home : "/tmp";
                snprintf(buffer, size, "%s/.cache", home);
        }
        if (access(buffer, F_OK) != 0) {
                r = mkdir(buffer, 0777);
                if (r != 0) {
                        syslog(LOG_WARNING,
                               "Cannot create log directory %s", buffer);
                        syslog(LOG_WARNING, "Falling back to using /tmp");
                        strcpy(buffer, "/tmp");
                }
        }
        strncat(buffer, "/", size - strlen(buffer) - 1);
        strncat(buffer, basename, size - strlen(buffer) - 1);
        strncat(buffer, ".log", size - strlen(buffer) - 1);
        return 0;
}


void hexdump(char* prefix, unsigned char* buf, int len)
// Dump a byte array as hex code, adding a prefix.
{
        int i;
        char str[1024];
        int pos = 0;

        if (prefix != NULL) {
                strncpy(str, prefix, sizeof(str));
                pos = strnlen(str, sizeof(str));
        }
        if (len > 0) {
                for (i = 0; i < len; i++) {
                        if (pos + 3 >= sizeof(str))
                                break;

                        if (!(i % 8))
                                str[pos++] = ' ';

                        sprintf(str + pos, "%02x ", buf[i]);

                        pos += 3;
                }
        } else {
                strncpy(str + pos, "NO DATA", sizeof(str));
        }
        log_trace("%s", str);
}