source: MondoRescue/branches/3.2/mindi-busybox/init/bootchartd.c

/* vi: set sw=4 ts=4: */
/*
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

//applet:IF_BOOTCHARTD(APPLET(bootchartd, BB_DIR_SBIN, BB_SUID_DROP))

//kbuild:lib-$(CONFIG_BOOTCHARTD) += bootchartd.o

//config:config BOOTCHARTD
//config:   bool "bootchartd"
//config:   default y
//config:   help
//config:     bootchartd is commonly used to profile the boot process
//config:     for the purpose of speeding it up. In this case, it is started
//config:     by the kernel as the init process. This is configured by adding
//config:     the init=/sbin/bootchartd option to the kernel command line.
//config:
//config:     It can also be used to monitor the resource usage of a specific
//config:     application or the running system in general. In this case,
//config:     bootchartd is started interactively by running bootchartd start
//config:     and stopped using bootchartd stop.
//config:
//config:config FEATURE_BOOTCHARTD_BLOATED_HEADER
//config:   bool "Compatible, bloated header"
//config:   default y
//config:   depends on BOOTCHARTD
//config:   help
//config:     Create extended header file compatible with "big" bootchartd.
//config:     "Big" bootchartd is a shell script and it dumps some
//config:     "convenient" info int the header, such as:
//config:       title = Boot chart for `hostname` (`date`)
//config:       system.uname = `uname -srvm`
//config:       system.release = `cat /etc/DISTRO-release`
//config:       system.cpu = `grep '^model name' /proc/cpuinfo | head -1` ($cpucount)
//config:       system.kernel.options = `cat /proc/cmdline`
//config:     This data is not mandatory for bootchart graph generation,
//config:     and is considered bloat. Nevertheless, this option
//config:     makes bootchartd applet to dump a subset of it.
//config:
//config:config FEATURE_BOOTCHARTD_CONFIG_FILE
//config:   bool "Support bootchartd.conf"
//config:   default y
//config:   depends on BOOTCHARTD
//config:   help
//config:     Enable reading and parsing of $PWD/bootchartd.conf
//config:     and /etc/bootchartd.conf files.

#include "libbb.h"
/* After libbb.h, since it needs sys/types.h on some systems */
#include <sys/utsname.h>

#ifdef __linux__
# include <sys/mount.h>
# ifndef MS_SILENT
#  define MS_SILENT      (1 << 15)
# endif
# ifndef MNT_DETACH
#  define MNT_DETACH 0x00000002
# endif
#endif

#define BC_VERSION_STR "0.8"

/* For debugging, set to 0:
 * strace won't work with DO_SIGNAL_SYNC set to 1.
 */
#define DO_SIGNAL_SYNC 1


//$PWD/bootchartd.conf and /etc/bootchartd.conf:
//supported options:
//# Sampling period (in seconds)
//SAMPLE_PERIOD=0.2
//
//not yet supported:
//# tmpfs size
//# (32 MB should suffice for ~20 minutes worth of log data, but YMMV)
//TMPFS_SIZE=32m
//
//# Whether to enable and store BSD process accounting information.  The
//# kernel needs to be configured to enable v3 accounting
//# (CONFIG_BSD_PROCESS_ACCT_V3). accton from the GNU accounting utilities
//# is also required.
//PROCESS_ACCOUNTING="no"
//
//# Tarball for the various boot log files
//BOOTLOG_DEST=/var/log/bootchart.tgz
//
//# Whether to automatically stop logging as the boot process completes.
//# The logger will look for known processes that indicate bootup completion
//# at a specific runlevel (e.g. gdm-binary, mingetty, etc.).
//AUTO_STOP_LOGGER="yes"
//
//# Whether to automatically generate the boot chart once the boot logger
//# completes.  The boot chart will be generated in $AUTO_RENDER_DIR.
//# Note that the bootchart package must be installed.
//AUTO_RENDER="no"
//
//# Image format to use for the auto-generated boot chart
//# (choose between png, svg and eps).
//AUTO_RENDER_FORMAT="png"
//
//# Output directory for auto-generated boot charts
//AUTO_RENDER_DIR="/var/log"


/* Globals */
struct globals {
    char jiffy_line[COMMON_BUFSIZE];
} FIX_ALIASING;
#define G (*(struct globals*)&bb_common_bufsiz1)
#define INIT_G() do { } while (0)

static void dump_file(FILE *fp, const char *filename)
{
    int fd = open(filename, O_RDONLY);
    if (fd >= 0) {
        fputs(G.jiffy_line, fp);
        fflush(fp);
        bb_copyfd_eof(fd, fileno(fp));
        close(fd);
        fputc('\n', fp);
    }
}

static int dump_procs(FILE *fp, int look_for_login_process)
{
    struct dirent *entry;
    DIR *dir = opendir("/proc");
    int found_login_process = 0;

    fputs(G.jiffy_line, fp);
    while ((entry = readdir(dir)) != NULL) {
        char name[sizeof("/proc/%u/cmdline") + sizeof(int)*3];
        int stat_fd;
        unsigned pid = bb_strtou(entry->d_name, NULL, 10);
        if (errno)
            continue;

        /* Android's version reads /proc/PID/cmdline and extracts
         * non-truncated process name. Do we want to do that? */

        sprintf(name, "/proc/%u/stat", pid);
        stat_fd = open(name, O_RDONLY);
        if (stat_fd >= 0) {
            char *p;
            char stat_line[4*1024];
            int rd = safe_read(stat_fd, stat_line, sizeof(stat_line)-2);

            close(stat_fd);
            if (rd < 0)
                continue;
            stat_line[rd] = '\0';
            p = strchrnul(stat_line, '\n');
            *p++ = '\n';
            *p = '\0';
            fputs(stat_line, fp);
            if (!look_for_login_process)
                continue;
            p = strchr(stat_line, '(');
            if (!p)
                continue;
            p++;
            strchrnul(p, ')')[0] = '\0';
            /* Is it gdm, kdm or a getty? */
            if (((p[0] == 'g' || p[0] == 'k' || p[0] == 'x') && p[1] == 'd' && p[2] == 'm')
             || strstr(p, "getty")
            ) {
                found_login_process = 1;
            }
        }
    }
    closedir(dir);
    fputc('\n', fp);
    return found_login_process;
}

static char *make_tempdir(void)
{
    char template[] = "/tmp/bootchart.XXXXXX";
    char *tempdir = xstrdup(mkdtemp(template));
    if (!tempdir) {
#ifdef __linux__
        /* /tmp is not writable (happens when we are used as init).
         * Try to mount a tmpfs, them cd and lazily unmount it.
         * Since we unmount it at once, we can mount it anywhere.
         * Try a few locations which are likely ti exist.
         */
        static const char dirs[] = "/mnt\0""/tmp\0""/boot\0""/proc\0";
        const char *try_dir = dirs;
        while (mount("none", try_dir, "tmpfs", MS_SILENT, "size=16m") != 0) {
            try_dir += strlen(try_dir) + 1;
            if (!try_dir[0])
                bb_perror_msg_and_die("can't %smount tmpfs", "");
        }
        //bb_error_msg("mounted tmpfs on %s", try_dir);
        xchdir(try_dir);
        if (umount2(try_dir, MNT_DETACH) != 0) {
            bb_perror_msg_and_die("can't %smount tmpfs", "un");
        }
#else
        bb_perror_msg_and_die("can't create temporary directory");
#endif
    } else {
        xchdir(tempdir);
    }
    return tempdir;
}

static void do_logging(unsigned sample_period_us, int process_accounting)
{
    FILE *proc_stat = xfopen("proc_stat.log", "w");
    FILE *proc_diskstats = xfopen("proc_diskstats.log", "w");
    //FILE *proc_netdev = xfopen("proc_netdev.log", "w");
    FILE *proc_ps = xfopen("proc_ps.log", "w");
    int look_for_login_process = (getppid() == 1);
    unsigned count = 60*1000*1000 / sample_period_us; /* ~1 minute */

    if (process_accounting) {
        close(xopen("kernel_pacct", O_WRONLY | O_CREAT | O_TRUNC));
        acct("kernel_pacct");
    }

    while (--count && !bb_got_signal) {
        char *p;
        int len = open_read_close("/proc/uptime", G.jiffy_line, sizeof(G.jiffy_line)-2);
        if (len < 0)
            goto wait_more;
        /* /proc/uptime has format "NNNNNN.MM NNNNNNN.MM" */
        /* we convert it to "NNNNNNMM\n" (using first value) */
        G.jiffy_line[len] = '\0';
        p = strchr(G.jiffy_line, '.');
        if (!p)
            goto wait_more;
        while (isdigit(*++p))
            p[-1] = *p;
        p[-1] = '\n';
        p[0] = '\0';

        dump_file(proc_stat, "/proc/stat");
        dump_file(proc_diskstats, "/proc/diskstats");
        //dump_file(proc_netdev, "/proc/net/dev");
        if (dump_procs(proc_ps, look_for_login_process)) {
            /* dump_procs saw a getty or {g,k,x}dm
             * stop logging in 2 seconds:
             */
            if (count > 2*1000*1000 / sample_period_us)
                count = 2*1000*1000 / sample_period_us;
        }
        fflush_all();
 wait_more:
        usleep(sample_period_us);
    }
}

static void finalize(char *tempdir, const char *prog, int process_accounting)
{
    //# Stop process accounting if configured
    //local pacct=
    //[ -e kernel_pacct ] && pacct=kernel_pacct

    FILE *header_fp = xfopen("header", "w");

    if (process_accounting)
        acct(NULL);

    if (prog)
        fprintf(header_fp, "profile.process = %s\n", prog);

    fputs("version = "BC_VERSION_STR"\n", header_fp);
    if (ENABLE_FEATURE_BOOTCHARTD_BLOATED_HEADER) {
        char *hostname;
        char *kcmdline;
        time_t t;
        struct tm tm_time;
        /* x2 for possible localized weekday/month names */
        char date_buf[sizeof("Mon Jun 21 05:29:03 CEST 2010") * 2];
        struct utsname unamebuf;

        hostname = safe_gethostname();
        time(&t);
        localtime_r(&t, &tm_time);
        strftime(date_buf, sizeof(date_buf), "%a %b %e %H:%M:%S %Z %Y", &tm_time);
        fprintf(header_fp, "title = Boot chart for %s (%s)\n", hostname, date_buf);
        if (ENABLE_FEATURE_CLEAN_UP)
            free(hostname);

        uname(&unamebuf); /* never fails */
        /* same as uname -srvm */
        fprintf(header_fp, "system.uname = %s %s %s %s\n",
                unamebuf.sysname,
                unamebuf.release,
                unamebuf.version,
                unamebuf.machine
        );

        //system.release = `cat /etc/DISTRO-release`
        //system.cpu = `grep '^model name' /proc/cpuinfo | head -1` ($cpucount)

        kcmdline = xmalloc_open_read_close("/proc/cmdline", NULL);
        /* kcmdline includes trailing "\n" */
        fprintf(header_fp, "system.kernel.options = %s", kcmdline);
        if (ENABLE_FEATURE_CLEAN_UP)
            free(kcmdline);
    }
    fclose(header_fp);

    /* Package log files */
    system(xasprintf("tar -zcf /var/log/bootlog.tgz header %s *.log", process_accounting ? "kernel_pacct" : ""));
    /* Clean up (if we are not in detached tmpfs) */
    if (tempdir) {
        unlink("header");
        unlink("proc_stat.log");
        unlink("proc_diskstats.log");
        //unlink("proc_netdev.log");
        unlink("proc_ps.log");
        if (process_accounting)
            unlink("kernel_pacct");
        rmdir(tempdir);
    }

    /* shell-based bootchartd tries to run /usr/bin/bootchart if $AUTO_RENDER=yes:
     * /usr/bin/bootchart -o "$AUTO_RENDER_DIR" -f $AUTO_RENDER_FORMAT "$BOOTLOG_DEST"
     */
}

//usage:#define bootchartd_trivial_usage
//usage:       "start [PROG ARGS]|stop|init"
//usage:#define bootchartd_full_usage "\n\n"
//usage:       "Create /var/log/bootchart.tgz with boot chart data\n"
//usage:     "\nstart: start background logging; with PROG, run PROG, then kill logging with USR1"
//usage:     "\nstop: send USR1 to all bootchartd processes"
//usage:     "\ninit: start background logging; stop when getty/xdm is seen (for init scripts)"
//usage:     "\nUnder PID 1: as init, then exec $bootchart_init, /init, /sbin/init"

int bootchartd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int bootchartd_main(int argc UNUSED_PARAM, char **argv)
{
    unsigned sample_period_us;
    pid_t parent_pid, logger_pid;
    smallint cmd;
    int process_accounting;
    enum {
        CMD_STOP = 0,
        CMD_START,
        CMD_INIT,
        CMD_PID1, /* used to mark pid 1 case */
    };

    INIT_G();

    parent_pid = getpid();
    if (argv[1]) {
        cmd = index_in_strings("stop\0""start\0""init\0", argv[1]);
        if (cmd < 0)
            bb_show_usage();
        if (cmd == CMD_STOP) {
            pid_t *pidList = find_pid_by_name("bootchartd");
            while (*pidList != 0) {
                if (*pidList != parent_pid)
                    kill(*pidList, SIGUSR1);
                pidList++;
            }
            return EXIT_SUCCESS;
        }
    } else {
        if (parent_pid != 1)
            bb_show_usage();
        cmd = CMD_PID1;
    }

    /* Here we are in START, INIT or CMD_PID1 state */

    /* Read config file: */
    sample_period_us = 200 * 1000;
    process_accounting = 0;
    if (ENABLE_FEATURE_BOOTCHARTD_CONFIG_FILE) {
        char* token[2];
        parser_t *parser = config_open2("/etc/bootchartd.conf" + 5, fopen_for_read);
        if (!parser)
            parser = config_open2("/etc/bootchartd.conf", fopen_for_read);
        while (config_read(parser, token, 2, 0, "#=", PARSE_NORMAL & ~PARSE_COLLAPSE)) {
            if (strcmp(token[0], "SAMPLE_PERIOD") == 0 && token[1])
                sample_period_us = atof(token[1]) * 1000000;
            if (strcmp(token[0], "PROCESS_ACCOUNTING") == 0 && token[1]
             && (strcmp(token[1], "on") == 0 || strcmp(token[1], "yes") == 0)
            ) {
                process_accounting = 1;
            }
        }
        config_close(parser);
        if ((int)sample_period_us <= 0)
            sample_period_us = 1; /* prevent division by 0 */
    }

    /* Create logger child: */
    logger_pid = fork_or_rexec(argv);

    if (logger_pid == 0) { /* child */
        char *tempdir;

        bb_signals(0
            + (1 << SIGUSR1)
            + (1 << SIGUSR2)
            + (1 << SIGTERM)
            + (1 << SIGQUIT)
            + (1 << SIGINT)
            + (1 << SIGHUP)
            , record_signo);

        if (DO_SIGNAL_SYNC)
            /* Inform parent that we are ready */
            raise(SIGSTOP);

        /* If we are started by kernel, PATH might be unset.
         * In order to find "tar", let's set some sane PATH:
         */
        if (cmd == CMD_PID1 && !getenv("PATH"))
            putenv((char*)bb_PATH_root_path);

        tempdir = make_tempdir();
        do_logging(sample_period_us, process_accounting);
        finalize(tempdir, cmd == CMD_START ? argv[2] : NULL, process_accounting);
        return EXIT_SUCCESS;
    }

    /* parent */

    USE_FOR_NOMMU(argv[0][0] &= 0x7f); /* undo fork_or_rexec() damage */

    if (DO_SIGNAL_SYNC) {
        /* Wait for logger child to set handlers, then unpause it.
         * Otherwise with short-lived PROG (e.g. "bootchartd start true")
         * we might send SIGUSR1 before logger sets its handler.
         */
        waitpid(logger_pid, NULL, WUNTRACED);
        kill(logger_pid, SIGCONT);
    }

    if (cmd == CMD_PID1) {
        char *bootchart_init = getenv("bootchart_init");
        if (bootchart_init)
            execl(bootchart_init, bootchart_init, NULL);
        execl("/init", "init", NULL);
        execl("/sbin/init", "init", NULL);
        bb_perror_msg_and_die("can't execute '%s'", "/sbin/init");
    }

    if (cmd == CMD_START && argv[2]) { /* "start PROG ARGS" */
        pid_t pid = xvfork();
        if (pid == 0) { /* child */
            argv += 2;
            BB_EXECVP_or_die(argv);
        }
        /* parent */
        waitpid(pid, NULL, 0);
        kill(logger_pid, SIGUSR1);
    }

    return EXIT_SUCCESS;
}