/*
    CCpp.cpp

    Copyright (C) 2009  Zdenek Prikryl (zprikryl@redhat.com)
    Copyright (C) 2009  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.

    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <set>
#include "abrtlib.h"
#include "CCpp.h"
#include "abrt_exception.h"
#include "comm_layer_inner.h"
#include "Polkit.h"

using namespace std;

#define CORE_PATTERN_IFACE      "/proc/sys/kernel/core_pattern"
#define CORE_PATTERN            "|"CCPP_HOOK_PATH" "DEBUG_DUMPS_DIR" %p %s %u %c"
#define CORE_PIPE_LIMIT_IFACE   "/proc/sys/kernel/core_pipe_limit"
/* core_pipe_limit specifies how many dump_helpers might run at the same time
0 - means unlimited, but the it's not guaranteed that /proc/<pid> of crashing
process might not be available for dump_helper
4 - means that 4 dump_helpers can run at the same time, which should be enough
for ABRT, we can miss some crashes, but what are the odds that more processes
crash at the same time? This value has been recommended by nhorman
*/
#define CORE_PIPE_LIMIT "4"

#define DEBUGINFO_CACHE_DIR     LOCALSTATEDIR"/cache/abrt-di"

CAnalyzerCCpp::CAnalyzerCCpp() :
    m_bBacktrace(true),
    m_bBacktraceRemotes(false),
    m_bMemoryMap(false),
    m_bInstallDebugInfo(true),
    m_nDebugInfoCacheMB(4000),
    m_nGdbTimeoutSec(60)
{}

/*
 this is just a workaround until kernel changes it's behavior
 when handling pipes in core_pattern
*/
#ifdef HOSTILE_KERNEL
#define CORE_SIZE_PATTERN "Max core file size=1:unlimited"
static int isdigit_str(char *str)
{
    do {
        if (*str < '0' || *str > '9')
            return 0;
    } while (*++str);
    return 1;
}

static int set_limits()
{
    DIR *dir = opendir("/proc");
    if (!dir) {
        /* this shouldn't fail, but to be safe.. */
        return 1;
    }

    struct dirent *ent;
    while ((ent = readdir(dir)) != NULL) {
        if (!isdigit_str(ent->d_name))
            continue;

        char limits_name[sizeof("/proc/%s/limits") + sizeof(long)*3];
        snprintf(limits_name, sizeof(limits_name), "/proc/%s/limits", ent->d_name);
        FILE *limits_fp = fopen(limits_name, "r");
        if (!limits_fp) {
            break;
        }

        char line[128];
        char *ulimit_c = NULL;
        while (1) {
            if (fgets(line, sizeof(line)-1, limits_fp) == NULL)
                break;
            if (strncmp(line, "Max core file size", sizeof("Max core file size")-1) == 0) {
                ulimit_c = skip_whitespace(line + sizeof("Max core file size")-1);
                skip_non_whitespace(ulimit_c)[0] = '\0';
                break;
            }
        }
        fclose(limits_fp);
        if (!ulimit_c || ulimit_c[0] != '0' || ulimit_c[1] != '\0') {
            /*process has nonzero ulimit -c, so need to modify it*/
            continue;
        }
        /* echo -n 'Max core file size=1:unlimited' >/proc/PID/limits */
        int fd = open(limits_name, O_WRONLY);
        if (fd >= 0) {
            errno = 0;
            /*full_*/
            ssize_t n = write(fd, CORE_SIZE_PATTERN, sizeof(CORE_SIZE_PATTERN)-1);
            if (n < sizeof(CORE_SIZE_PATTERN)-1)
                log("warning: can't write core_size limit to: %s", limits_name);
            close(fd);
        }
        else
        {
            log("warning: can't open %s for writing", limits_name);
        }
    }
    closedir(dir);
    return 0;
}
#endif /* HOSTILE_KERNEL */

void CAnalyzerCCpp::Init()
{
    FILE *fp = fopen(CORE_PATTERN_IFACE, "r");
    if (fp)
    {
        char line[PATH_MAX];
        if (fgets(line, sizeof(line), fp))
            m_sOldCorePattern = line;
        fclose(fp);
    }
    if (m_sOldCorePattern[0] == '|')
    {
        if (m_sOldCorePattern == CORE_PATTERN)
        {
            log("warning: %s already contains %s, "
                "did abrt daemon crash recently?",
                CORE_PATTERN_IFACE, CORE_PATTERN);
            /* There is no point in "restoring" CORE_PATTERN_IFACE
             * to CORE_PATTERN on exit. Will restore to a default value:
             */
            m_sOldCorePattern = "core";
        } else {
            log("warning: %s was already set to run a crash analyser (%s), "
                "abrt may interfere with it",
                CORE_PATTERN_IFACE, CORE_PATTERN);
        }
    }
#ifdef HOSTILE_KERNEL
    if (set_limits() != 0)
        log("warning: failed to set core_size limit, ABRT won't detect crashes in"
            "compiled apps");
#endif

    fp = fopen(CORE_PATTERN_IFACE, "w");
    if (fp)
    {
        fputs(CORE_PATTERN, fp);
        fclose(fp);
    }

    /* read the core_pipe_limit and change it if it's == 0
       otherwise the abrt-hook-ccpp won't be able to read /proc/<pid>
       of the crashing process
    */
    fp = fopen(CORE_PIPE_LIMIT_IFACE, "r");
    if (fp)
    {
        /* we care only about the first char, if it's
         * not '0' then we don't have to change it,
         * because it means that it's already != 0
         */
        char pipe_limit[2];
        if (!fgets(pipe_limit, sizeof(pipe_limit), fp))
            pipe_limit[0] = '1'; /* not 0 */
        fclose(fp);
        if (pipe_limit[0] == '0')
        {
            fp = fopen(CORE_PIPE_LIMIT_IFACE, "w");
            if (fp)
            {
                fputs(CORE_PIPE_LIMIT, fp);
                fclose(fp);
            }
            else
            {
                log("warning: failed to set core_pipe_limit, ABRT won't detect"
                    "crashes in compiled apps if kernel > 2.6.31");
            }
        }
    }
}

void CAnalyzerCCpp::DeInit()
{
    /* no need to restore the core_pipe_limit, because it's only used
       when there is s pipe in core_pattern
    */
    FILE *fp = fopen(CORE_PATTERN_IFACE, "w");
    if (fp)
    {
        fputs(m_sOldCorePattern.c_str(), fp);
        fclose(fp);
    }
}

void CAnalyzerCCpp::SetSettings(const map_plugin_settings_t& pSettings)
{
    m_pSettings = pSettings;

    map_plugin_settings_t::const_iterator end = pSettings.end();
    map_plugin_settings_t::const_iterator it;
    it = pSettings.find("Backtrace");
    if (it != end)
    {
        m_bBacktrace = string_to_bool(it->second.c_str());
    }
    it = pSettings.find("BacktraceRemotes");
    if (it != end)
    {
        m_bBacktraceRemotes = string_to_bool(it->second.c_str());
    }
    it = pSettings.find("MemoryMap");
    if (it != end)
    {
        m_bMemoryMap = string_to_bool(it->second.c_str());
    }
    it = pSettings.find("DebugInfo");
    if (it != end)
    {
        m_sDebugInfo = it->second;
    }
    it = pSettings.find("DebugInfoCacheMB");
    if (it != end)
    {
        m_nDebugInfoCacheMB = xatou(it->second.c_str());
    }
    it = pSettings.find("GdbTimeoutSec");
    if (it != end)
    {
        m_nGdbTimeoutSec = xatoi_u(it->second.c_str());
    }
    it = pSettings.find("InstallDebugInfo");
    if (it == end) //compat, remove after 0.0.11
        it = pSettings.find("InstallDebuginfo");
    if (it != end)
    {
        m_bInstallDebugInfo = string_to_bool(it->second.c_str());
    }
    m_sDebugInfoDirs = DEBUGINFO_CACHE_DIR;
    it = pSettings.find("ReadonlyLocalDebugInfoDirs");
    if (it != end)
    {
        m_sDebugInfoDirs += ':';
        m_sDebugInfoDirs += it->second;
    }
}

//ok to delete?
//const map_plugin_settings_t& CAnalyzerCCpp::GetSettings()
//{
//    m_pSettings["MemoryMap"] = m_bMemoryMap ? "yes" : "no";
//    m_pSettings["DebugInfo"] = m_sDebugInfo;
//    m_pSettings["DebugInfoCacheMB"] = to_string(m_nDebugInfoCacheMB);
//    m_pSettings["InstallDebugInfo"] = m_bInstallDebugInfo ? "yes" : "no";
//
//    return m_pSettings;
//}

PLUGIN_INFO(ANALYZER,
            CAnalyzerCCpp,
            "CCpp",
            "0.0.1",
            _("Analyzes crashes in C/C++ programs"),
            "zprikryl@redhat.com",
            "https://fedorahosted.org/abrt/wiki",
            "");