diff options
Diffstat (limited to 'syslogd/proto.c')
| -rw-r--r-- | syslogd/proto.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/syslogd/proto.c b/syslogd/proto.c new file mode 100644 index 0000000..3487dbd --- /dev/null +++ b/syslogd/proto.c @@ -0,0 +1,177 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +/* + * Copyright (C) 2018 - David Oberhollenzer + * + * 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 3 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 <https://www.gnu.org/licenses/>. + */ +#include <stddef.h> +#include <string.h> +#include <ctype.h> +#include <time.h> + +#include "proto.h" + +static const char *months[] = { + "Jan", "Feb", "Mar", "Apr", + "May", "Jun", "Jul", "Aug", + "Sep", "Oct", "Nov", "Dec" +}; + +static const int days[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; + +static int isleap(int year) +{ + return ((year % 4 == 0) && (year % 100 != 0)) || ((year % 400) == 0); +} + +static int mdays(int year, int month) +{ + return (isleap(year) && month == 2) ? 29 : days[month - 1]; +} + +static char *read_num(char *str, int *out, int maxval) +{ + if (str == NULL || !isdigit(*str)) + return NULL; + for (*out = 0; isdigit(*str); ++str) { + (*out) = (*out) * 10 + (*str) - '0'; + if ((*out) > maxval) + return NULL; + } + return str; +} + +static char *skip_space(char *str) +{ + if (str == NULL || !isspace(*str)) + return NULL; + while (isspace(*str)) + ++str; + return str; +} + +static char *read_date_bsd(char *str, struct tm *tm) +{ + int year, month, day, hour, minute, second; + time_t t; + + /* decode date */ + for (month = 0; month < 12; ++month) { + if (strncmp(str, months[month], 3) == 0) { + str = skip_space(str + 3); + break; + } + } + + str = read_num(str, &day, 31); + str = skip_space(str); + + t = time(NULL); + if (localtime_r(&t, tm) == NULL) + return NULL; + + year = tm->tm_year; + + /* sanity check */ + if (str == NULL || month >= 12 || day < 1) + return NULL; + if (month == 11 && tm->tm_mon == 0) + --year; + if (day > mdays(year + 1900, month + 1)) + return NULL; + + /* decode time */ + str = read_num(str, &hour, 23); + if (str == NULL || *(str++) != ':') + return NULL; + str = read_num(str, &minute, 59); + if (str == NULL || *(str++) != ':') + return NULL; + str = read_num(str, &second, 59); + str = skip_space(str); + + /* store result */ + memset(tm, 0, sizeof(*tm)); + tm->tm_sec = second; + tm->tm_min = minute; + tm->tm_hour = hour; + tm->tm_mday = day; + tm->tm_mon = month; + tm->tm_year = year; + return str; +} + +static char *decode_priority(char *str, int *priority) +{ + while (isspace(*str)) + ++str; + if (*(str++) != '<') + return NULL; + str = read_num(str, priority, 23 * 8 + 7); + if (str == NULL || *(str++) != '>') + return NULL; + while (isspace(*str)) + ++str; + return str; +} + +int syslog_msg_parse(syslog_msg_t *msg, char *str) +{ + char *ident, *ptr; + struct tm tstamp; + pid_t pid = 0; + int priority; + + memset(msg, 0, sizeof(*msg)); + + str = decode_priority(str, &priority); + if (str == NULL) + return -1; + + msg->facility = priority >> 3; + msg->level = priority & 0x07; + + str = read_date_bsd(str, &tstamp); + if (str == NULL) + return -1; + + ident = str; + while (*str != '\0' && *str != ':') + ++str; + + if (*str == ':') { + *(str++) = '\0'; + while (isspace(*str)) + ++str; + + ptr = ident; + while (*ptr != '[' && *ptr != '\0') + ++ptr; + + if (*ptr == '[') { + *(ptr++) = '\0'; + + while (isdigit(*ptr)) + pid = pid * 10 + *(ptr++) - '0'; + } + } else { + ident = NULL; + } + + msg->timestamp = mktime(&tstamp); + msg->pid = pid; + msg->ident = ident; + msg->message = str; + return 0; +} |