init.c

linux 安装程序

/*
 * init.c
 * 
 * This is the install type init 
 *
 * Erik Troan ([e-mail])
 * Jeremy Katz ([e-mail])
 *
 * Copyright 1996 - 2004 Red Hat, Inc.
 *
 * This software may be freely redistributed under the terms of the GNU
 * general public license.
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#if USE_MINILIBC
#include "minilibc.h"
#ifndef SOCK_STREAM
# define SOCK_STREAM 1
#endif 
#else
#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <net/if.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/klog.h>
#include <sys/mount.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/swap.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/reboot.h>
#include <linux/vt.h>
#include <termios.h>
#include <libgen.h>

#include "devt.h"
#include "devices.h"

#define syslog klogctl
#endif

#include <asm/types.h>
#include <linux/cdrom.h>
#include <linux/serial.h>

#ifndef MS_REMOUNT
#define MS_REMOUNT          32
#endif

#define ENV_PATH            0
#define ENV_LD_LIBRARY_PATH 1
#define ENV_HOME            2
#define ENV_TERM            3
#define ENV_DEBUG           4
#define ENV_TERMINFO        5
#define ENV_PYTHONPATH      6
#define ENV_MALLOC_CHECK    7
#define ENV_MALLOC_PERTURB  8

/*
 * Snakes On A Plane...
 *
 * Define this macro if you want init to launch /bin/bash instead of loader.
 * You will want to populate initrd.img with bash, libraries, other commands
 * like strace or something, and whatever else you want.  This is purely for
 * debugging loader.  Things you will likely want in a debugging initrd:
 *    /lib/libc.so.6
 *    /lib/libtermcap.so.2
 *    /lib/ld-linux.so.2
 *    /lib/libdl.so.2
 *    /bin/bash
 *    /bin/strace
 * You get the idea.  Be creative.  Be imaginative.  Be bold.
 */
#undef SNAKES_ON_A_PLANE
/* #define SNAKES_ON_A_PLANE 1 */

char * env[] = {
    "PATH=/usr/bin:/bin:/sbin:/usr/sbin:/mnt/sysimage/bin:"
    "/mnt/sysimage/usr/bin:/mnt/sysimage/usr/sbin:/mnt/sysimage/sbin:"
    "/mnt/sysimage/usr/X11R6/bin",

    /* we set a nicer ld library path specifically for bash -- a full
       one makes anaconda unhappy */
#if defined(__x86_64__) || defined(__s390x__) || defined(__ppc64__)
    "LD_LIBRARY_PATH=/lib64:/usr/lib64:/lib:/usr/lib",
#else
    "LD_LIBRARY_PATH=/lib:/usr/lib",
#endif
    "HOME=/",
    "TERM=linux",
    "DEBUG=",
    "TERMINFO=/etc/linux-terminfo",
    "PYTHONPATH=/tmp/updates",
    "_MALLOC_CHECK=2",
    "MALLOC_PERTURB_=204",
    NULL
};

/* 
 * this needs to handle the following cases:
 *
 *	1) run from a CD root filesystem
 *	2) run from a read only nfs rooted filesystem
 *      3) run from a floppy
 *	4) run from a floppy that's been loaded into a ramdisk 
 *
 */

int testing=0;
void unmountFilesystems(void);
void disableSwap(void);
void shutDown(int noKill, int doReboot, int doPowerOff);
static int getNoKill(void);
struct termios ts;

static int mystrstr(char *str1, char *str2) {
    char *p;
    int rc=0;

    for (p=str1; *p; p++) {
        if (*p == *str2) {
            char *s, *t;

            rc = 1;
            for (s=p, t=str2; *s && *t; s++, t++)
                if (*s != *t) {
                    rc = 0;
                    p++;
                }

            if (rc)
                return rc;
        } 
    }
    return rc;
}

static void printstr(char * string) {
    int ret;
    ret = write(1, string, strlen(string));
}

static void fatal_error(int usePerror) {
/* FIXME */
#if 0
    if (usePerror) 
        perror("failed:");
    else
#endif
    printf("failed.\n");

    printf("\nI can't recover from this.\n");
    if (testing)
        exit(0);
#if !defined(__s390__) && !defined(__s390x__)
    while (1) ;
#endif
}

static int logChunk(int len, char *inbuf, char *outbuf) {
    int inctr, outctr;

    for (inctr = 0, outctr = 0; inctr < len; inctr++) {
        /* If the character is a NULL that's immediately followed by a open
         * bracket, we've found the beginning of a new kernel message.  Put in
         * a line separator.
         */
        if (inbuf[inctr] == '\0' && inctr+1 < len && inbuf[inctr+1] == '<') {
            outbuf[outctr] = '\n';
            outctr++;
        }

        /* Or, if we see a NULL right before the end of the chunk, that's also
         * a good place to add a separator.
         */
        else if (inbuf[inctr] == '\0' && inctr+1 == len) {
            outbuf[outctr] = '\n';
            outctr++;
        }

        /* Otherwise, simply output the character as long as it's not NULL. */
        else if (inbuf[inctr] != '\0') {
            outbuf[outctr] = inbuf[inctr];
            outctr++;
        }
    }

    return outctr;
}

static void doklog(char * fn) {
    fd_set readset, unixs;
    int in, out, i;
    int log;
    socklen_t s;
    int sock = -1;
    struct sockaddr_un sockaddr;
    char inbuf[1024], outbuf[1024];
    int readfd;
    int ret;

    in = open("/proc/kmsg", O_RDONLY,0);
    if (in < 0) {
        /* FIXME: was perror */
        printstr("open /proc/kmsg");
        return;
    }

    out = open(fn, O_WRONLY, 0);
    if (out < 0) 
        printf("couldn't open %s for syslog -- still using /tmp/syslog\n", fn);

    log = open("/tmp/syslog", O_WRONLY | O_CREAT, 0644);
    if (log < 0) {
        /* FIXME: was perror */
        printstr("error opening /tmp/syslog");
        sleep(5);
	
        close(in);
        return;
    }

    /* if we get this far, we should be in good shape */

    if (fork()) {
        /* parent */
        close(in);
        close(out);
        close(log);
        return;
    }
    close(0); 
    close(1);
    close(2);

    dup2(1, log);

#if defined(USE_LOGDEV)
    /* now open the syslog socket */
    sockaddr.sun_family = AF_UNIX;
    strcpy(sockaddr.sun_path, "/dev/log");
    sock = socket(AF_UNIX, SOCK_STREAM, 0);
    if (sock < 0) {
        printf("error creating socket: %d\n", errno);
        sleep(5);
    }
    printstr("got socket\n");
    if (bind(sock, (struct sockaddr *) &sockaddr, sizeof(sockaddr.sun_family) + 
			strlen(sockaddr.sun_path))) {
        printf("bind error: %d\n", errno);
        sleep(5);
    }
    printstr("bound socket\n");
    chmod("/dev/log", 0666);
    if (listen(sock, 5)) {
        printf("listen error: %d\n", errno);
        sleep(5);
    }
#endif

    syslog(8, NULL, 1);

    FD_ZERO(&unixs);
    while (1) {
        memcpy(&readset, &unixs, sizeof(unixs));

        if (sock >= 0)
            FD_SET(sock, &readset);

        FD_SET(in, &readset);

        i = select(20, &readset, NULL, NULL, NULL);
        if (i <= 0) continue;

        if (FD_ISSET(in, &readset)) {
            i = read(in, inbuf, sizeof(inbuf));
            if (i > 0) {
                int loggedLen = logChunk(i, inbuf, outbuf);

                if (out >= 0)
                    ret = write(out, outbuf, loggedLen);
                ret = write(log, outbuf, loggedLen);
            }
        } 

        for (readfd = 0; readfd < 20; ++readfd) {
            if (FD_ISSET(readfd, &readset) && FD_ISSET(readfd, &unixs)) {
                i = read(readfd, inbuf, sizeof(inbuf));
                if (i > 0) {
                    int loggedLen = logChunk(i, inbuf, outbuf);

                    if (out >= 0)
                        ret = write(out, outbuf, loggedLen);

                    ret = write(log, outbuf, loggedLen);
                } else if (i == 0) {
                    /* socket closed */
                    close(readfd);
                    FD_CLR(readfd, &unixs);
                }
            }
        }

        if (sock >= 0 && FD_ISSET(sock, &readset)) {
            s = sizeof(sockaddr);
            readfd = accept(sock, (struct sockaddr *) &sockaddr, &s);
            if (readfd < 0) {
                if (out >= 0)
                    ret = write(out, "error in accept\n", 16);
                ret = write(log, "error in accept\n", 16);
                close(sock);
                sock = -1;
            } else {
                FD_SET(readfd, &unixs);
            }
        }
    }    
}

static int setupTerminal(int fd) {
    struct winsize winsize;
    int fdn, len;
    char buf[65535];

    if (ioctl(fd, TIOCGWINSZ, &winsize)) {
        printf("failed to get winsize");
        fatal_error(1);
    }

    winsize.ws_row = 24;
    winsize.ws_col = 80;

    if (ioctl(fd, TIOCSWINSZ, &winsize)) {
        printf("failed to set winsize");
        fatal_error(1);
    }

    /* use the no-advanced-video vt100 definition */
    env[ENV_TERM] = "TERM=vt100-nav";

    /* unless the user specifies that they want utf8 */
    if ((fdn = open("/proc/cmdline", O_RDONLY, 0)) != -1) {
        len = read(fdn, buf, sizeof(buf) - 1);
        close(fdn);
        if (len > 0 && mystrstr(buf, "utf8"))
            env[ENV_TERM] = "TERM=vt100";
    }

    return 0;
}

#if !defined(__s390__) && !defined(__s390x__)
static int termcmp(struct termios *a, struct termios *b) {
    if (a->c_iflag != b->c_iflag || a->c_oflag != b->c_oflag ||
        a->c_cflag != b->c_cflag || a->c_lflag != b->c_lflag ||
        a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
        return 1;
    return memcmp(a->c_cc, b->c_cc, sizeof(a->c_cc));
}
#endif

/* Recursive -- copied (and tweaked)from loader2/method.c */ 
static int copyDirectory(char * from, char * to) {
    DIR * dir;
    struct dirent * ent;
    int fd, outfd;
    char buf[4096];
    int i;
    struct stat sb;
    char filespec[256];
    char filespec2[256];
    char link[1024];
    int ret;

    mkdir(to, 0755);

    if (!(dir = opendir(from))) {
        printf("Failed to read directory %s: %s", from, strerror(errno));
        return 1;
    }

    errno = 0;
    while ((ent = readdir(dir))) {
        if (!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, "..")) continue;

        sprintf(filespec, "%s/%s", from, ent->d_name);
        sprintf(filespec2, "%s/%s", to, ent->d_name);

        lstat(filespec, &sb);

        if (S_ISDIR(sb.st_mode)) {
            if (copyDirectory(filespec, filespec2)) return 1;
        } else if (S_ISLNK(sb.st_mode)) {
            i = readlink(filespec, link, sizeof(link) - 1);
            link[i] = '\0';
            if (symlink(link, filespec2)) {
                printf("failed to symlink %s to %s: %s", filespec2, 
                       link, strerror(errno));
            }
        } else {
            fd = open(filespec, O_RDONLY);
            if (fd == -1) {
                printf("failed to open %s: %s", filespec, strerror(errno));
                return 1;
            } 
            outfd = open(filespec2, O_RDWR | O_TRUNC | O_CREAT, 0644);
            if (outfd == -1) {
                printf("failed to create %s: %s", filespec2, strerror(errno));
            } else {
                fchmod(outfd, sb.st_mode & 07777);

                while ((i = read(fd, buf, sizeof(buf))) > 0)
                    ret = write(outfd, buf, i);
                close(outfd);
            }

            close(fd);
        }

        errno = 0;
    }

    closedir(dir);

    return 0;
}

static void createDevices(void) {
    int i;

    for (i = 0; devnodes[i].devname != NULL; i++) {
        char devname[64];
        int type = -1;