/*
    Copyright (C) 2010  ABRT team
    Copyright (C) 2010  RedHat Inc

    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.

    Authors:
       Anton Arapov <anton@redhat.com>
       Arjan van de Ven <arjan@linux.intel.com>
 */
#include "abrtlib.h"
#include "KerneloopsSysLog.h"

static void queue_oops(vector_string_t &vec, const char *data, const char *version)
{
    vec.push_back(ssprintf("%s\n%s", version, data));
}

/*
 * extract_version tries to find the kernel version in given data
 */
static char *extract_version(const char *linepointer)
{
    if (strstr(linepointer, "Pid")
     || strstr(linepointer, "comm")
     || strstr(linepointer, "CPU")
     || strstr(linepointer, "REGS")
     || strstr(linepointer, "EFLAGS")
    ) {
        char* start;
        char* end;

        start = strstr((char*)linepointer, "2.6.");
        if (start)
        {
            end = strchr(start, ')');
            if (!end)
                end = strchrnul(start, ' ');
            return xstrndup(start, end-start);
        }
    }

    return NULL;
}

/*
 * extract_oops tries to find oops signatures in a log
 */
struct line_info {
    char *ptr;
    char level;
};

static int record_oops(vector_string_t &oopses, struct line_info* lines_info, int oopsstart, int oopsend)
{
    int q;
    int len;
    char *oops;
    char *version;

    len = 2;
    for (q = oopsstart; q <= oopsend; q++)
            len += strlen(lines_info[q].ptr) + 1;

    oops = (char*)xzalloc(len);

    version = NULL;
    for (q = oopsstart; q <= oopsend; q++)
    {
        if (!version)
            version = extract_version(lines_info[q].ptr);

        if (lines_info[q].ptr[0])
        {
            strcat(oops, lines_info[q].ptr);
            strcat(oops, "\n");
        }
    }
    int rv = 1;
    /* too short oopses are invalid */
    if (strlen(oops) > 100)
        queue_oops(oopses, oops, version ? version : "undefined");
    else
    {
        VERB3 log("Dropped oops: too short");
        rv = 0;
    }
    free(oops);
    free(version);
    return rv;
}
#define REALLOC_CHUNK 1000
int extract_oopses(vector_string_t &oopses, char *buffer, size_t buflen)
{
    char *c;
    int linecount = 0;
    int lines_info_alloc = 0;
    struct line_info *lines_info = NULL;

    /* Split buffer into lines */

    if (buflen != 0)
            buffer[buflen - 1] = '\n';  /* the buffer usually ends with \n, but let's make sure */
    c = buffer;
    while (c < buffer + buflen)
    {
        char linelevel;
        char *c9;
        char *colon;

        c9 = (char*)memchr(c, '\n', buffer + buflen - c); /* a \n will always be found */
        assert(c9);
        *c9 = '\0'; /* turn the \n into a string termination */
        if (c9 == c)
            goto next_line;

        /* Is it a syslog file (/var/log/messages or similar)?
         * Even though _usually_ it looks like "Nov 19 12:34:38 localhost kernel: xxx",
         * some users run syslog in non-C locale:
         * "2010-02-22T09:24:08.156534-08:00 gnu-4 gnome-session[2048]: blah blah"
         *  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ !!!
         * We detect it by checking for N:NN:NN pattern in first 15 chars
         * (and this still is not good enough... false positive: "pci 0000:15:00.0: PME# disabled")
         */
        colon = strchr(c, ':');
        if (colon && colon > c && colon < c + 15
         && isdigit(colon[-1]) /* N:... */
         && isdigit(colon[1]) /* ...N:NN:... */
         && isdigit(colon[2])
         && colon[3] == ':'
         && isdigit(colon[4]) /* ...N:NN:NN... */
         && isdigit(colon[5])
        ) {
            /* It's syslog file, not a bare dmesg */

            /* Skip non-kernel lines */
            char *kernel_str = strstr(c, "kernel: ");
            if (kernel_str == NULL)
            {
                /* if we see our own marker:
                 * "hostname abrt: Kerneloops: Reported 1 kernel oopses to Abrt"
                 * we know we submitted everything upto here already */
                if (strstr(c, "abrt:") && strstr(c, "Abrt"))
                {
                    VERB3 log("Found our marker at line %d, restarting line count from 0", linecount);
                    linecount = 0;
                    lines_info_alloc = 0;
                    free(lines_info);
                    lines_info = NULL;
                }
                goto next_line;
            }
            c = kernel_str + sizeof("kernel: ")-1;
        }

        linelevel = 0;
        /* store and remove kernel log level */
        if (*c == '<' && c[1] && c[2] == '>')
        {
            linelevel = c[1];
            c += 3;
        }
        /* remove jiffies time stamp counter if present */
        if (*c == '[')
        {
            char *c2 = strchr(c, '.');
            char *c3 = strchr(c, ']');
            if (c2 && c3 && (c2 < c3) && (c3-c) < 14 && (c2-c) < 8)
            {
                c = c3 + 1;
                if (*c == ' ')
                        c++;
            }
        }
        if (linecount >= lines_info_alloc)
        {
            lines_info_alloc += REALLOC_CHUNK;
            lines_info = (line_info*)xrealloc(lines_info,
                            lines_info_alloc * sizeof(struct line_info));
        }
        lines_info[linecount].ptr = c;
        lines_info[linecount].level = linelevel;
        linecount++;
next_line:
        c = c9 + 1;
    }

    /* Analyze lines */

    int i;
    char prevlevel = 0;
    int oopsstart = -1;
    int inbacktrace = 0;
    int oopsesfound = 0;

    i = 0;
    while (i < linecount)
    {
        char *curline = lines_info[i].ptr;

        if (curline == NULL)
        {
            i++;
            continue;
        }
        while (*curline == ' ')
                curline++;

        if (oopsstart < 0)
        {
            /* find start-of-oops markers */
            if (strstr(curline, "general protection fault:"))
                oopsstart = i;
            else if (strstr(curline, "BUG:"))
                oopsstart = i;
            else if (strstr(curline, "kernel BUG at"))
                oopsstart = i;
            else if (strstr(curline, "do_IRQ: stack overflow:"))
                oopsstart = i;
            else if (strstr(curline, "RTNL: assertion failed"))
                 oopsstart = i;
            else if (strstr(curline, "Eeek! page_mapcount(page) went negative!"))
                oopsstart = i;
            else if (strstr(curline, "near stack overflow (cur:"))
                oopsstart = i;
            else if (strstr(curline, "double fault:"))
                oopsstart = i;
            else if (strstr(curline, "Badness at"))
                oopsstart = i;
            else if (strstr(curline, "NETDEV WATCHDOG"))
                oopsstart = i;
            else if (strstr(curline, "WARNING: at ")) /* WARN_ON() generated message */
                oopsstart = i;
            else if (strstr(curline, "Unable to handle kernel"))
                oopsstart = i;
            else if (strstr(curline, "sysctl table check failed"))
                oopsstart = i;
            else if (strstr(curline, "INFO: possible recursive locking detected"))
                oopsstart = i;
            // Not needed: "--[ cut here ]--" is always followed
            // by "Badness at", "kernel BUG at", or "WARNING: at" string
            //else if (strstr(curline, "------------[ cut here ]------------"))
            //	oopsstart = i;
            else if (strstr(curline, "list_del corruption."))
                oopsstart = i;
            else if (strstr(curline, "list_add corruption."))
                oopsstart = i;
            if (strstr(curline, "Oops:") && i >= 3)
                oopsstart = i-3;

            if (oopsstart >= 0)
            {
                /* debug information */
                VERB3 {
                    log("Found oops at line %d: '%s'", oopsstart, lines_info[oopsstart].ptr);
                    if (oopsstart != i)
                            log("Trigger line is %d: '%s'", i, c);
                }
                /* try to find the end marker */
                int i2 = i + 1;
                while (i2 < linecount && i2 < (i+50))
                {
                    if (strstr(lines_info[i2].ptr, "---[ end trace"))
                    {
                        inbacktrace = 1;
                        i = i2;
                        break;
                    }
                    i2++;
                }
            }
        }

        /* Are we entering a call trace part? */
        /* a call trace starts with "Call Trace:" or with the " [<.......>] function+0xFF/0xAA" pattern */
        if (oopsstart >= 0 && !inbacktrace)
        {
            if (strstr(curline, "Call Trace:"))
                inbacktrace = 1;
            else
            if (strnlen(curline, 9) > 8
             && curline[0] == '[' && curline[1] == '<'
             && strstr(curline, ">]")
             && strstr(curline, "+0x")
             && strstr(curline, "/0x")
            ) {
                inbacktrace = 1;
            }
        }

        /* Are we at the end of an oops? */
        else if (oopsstart >= 0 && inbacktrace)
        {
            int oopsend = INT_MAX;

            /* line needs to start with " [" or have "] [" if it is still a call trace */
            /* example: "[<ffffffffa006c156>] radeon_get_ring_head+0x16/0x41 [radeon]" */
            if (curline[0] != '['
             && !strstr(curline, "] [")
             && !strstr(curline, "--- Exception")
             && !strstr(curline, "LR =")
             && !strstr(curline, "<#DF>")
             && !strstr(curline, "<IRQ>")
             && !strstr(curline, "<EOI>")
             && !strstr(curline, "<<EOE>>")
             && strncmp(curline, "Code: ", 6) != 0
             && strncmp(curline, "RIP ", 4) != 0
             && strncmp(curline, "RSP ", 4) != 0
            ) {
                oopsend = i-1; /* not a call trace line */
            }
            /* oops lines are always more than 8 chars long */
            else if (strnlen(curline, 8) < 8)
                oopsend = i-1;
            /* single oopses are of the same loglevel */
            else if (lines_info[i].level != prevlevel)
                oopsend = i-1;
            else if (strstr(curline, "Instruction dump:"))
                oopsend = i;
            /* if a new oops starts, this one has ended */
            else if (strstr(curline, "WARNING: at ") && oopsstart != i) /* WARN_ON() generated message */
                oopsend = i-1;
            else if (strstr(curline, "Unable to handle") && oopsstart != i)
                oopsend = i-1;
            /* kernel end-of-oops marker (not including marker itself) */
            else if (strstr(curline, "---[ end trace"))
                oopsend = i-1;

            if (oopsend <= i)
            {
                VERB3 log("End of oops at line %d (%d): '%s'", oopsend, i, lines_info[oopsend].ptr);
                if (record_oops(oopses, lines_info, oopsstart, oopsend))
                    oopsesfound++;
                oopsstart = -1;
                inbacktrace = 0;
            }
        }

        prevlevel = lines_info[i].level;
        i++;

        if (oopsstart >= 0)
        {
            /* Do we have a suspiciously long oops? Cancel it */
            if (i-oopsstart > 60)
            {
                inbacktrace = 0;
                oopsstart = -1;
                VERB3 log("Dropped oops, too long");
                continue;
            }
            if (!inbacktrace && i-oopsstart > 40)
            {
                /*inbacktrace = 0; - already is */
                oopsstart = -1;
                VERB3 log("Dropped oops, too long");
                continue;
            }
        }
    } /* while (i < linecount) */

    /* process last oops if we have one */
    if (oopsstart >= 0 && inbacktrace)
    {
        int oopsend = i-1;
        VERB3 log("End of oops at line %d (end of file): '%s'", oopsend, lines_info[oopsend].ptr);
        if (record_oops(oopses, lines_info, oopsstart, oopsend))
                oopsesfound++;
    }

    free(lines_info);
    return oopsesfound;
}