/* * $Id: diskd.c,v 1.11.2.1 2007/02/03 21:48:16 hno Exp $ * * DEBUG: section --    External DISKD process implementation. * AUTHOR: Harvest Derived * * SQUID Web Proxy Cache          http://www.squid-cache.org/ * ---------------------------------------------------------- * *  Squid is the result of efforts by numerous individuals from *  the Internet community; see the CONTRIBUTORS file for full *  details.   Many organizations have provided support for Squid's *  development; see the SPONSORS file for full details.  Squid is *  Copyrighted (C) 2001 by the Regents of the University of *  California; see the COPYRIGHT file for full details.  Squid *  incorporates software developed and/or copyrighted by other *  sources; see the CREDITS file for full details. * *  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., 59 Temple Place, Suite 330, Boston, MA 02111, USA. * */#include "config.h"#include "squid.h"#include <sys/ipc.h>#include <sys/msg.h>#include <sys/shm.h>#include "store_diskd.h"#undef assert#include <assert.h>#define DEBUG(LEVEL) if (LEVEL <= DebugLevel)typedef struct _file_state file_state;struct _file_state {    void *key;    file_state *next;    int id;    int fd;    off_t offset;};static hash_table *hash = NULL;static pid_t mypid;static char *shmbuf;static int DebugLevel = 0;static intdo_open(diomsg * r, int len, const char *buf){    int fd;    file_state *fs;    /*     * note r->offset holds open() flags     */    fd = open(buf, r->offset, 0600);    if (fd < 0) {	DEBUG(1) {	    fprintf(stderr, "%d %s: ", (int) mypid, buf);	    perror("open");	}	return -errno;    }    fs = xcalloc(1, sizeof(*fs));    fs->id = r->id;    fs->key = &fs->id;		/* gack */    fs->fd = fd;    hash_join(hash, (hash_link *) fs);    DEBUG(2)	fprintf(stderr, "%d OPEN  id %d, FD %d, fs %p\n",	(int) mypid,	fs->id,	fs->fd,	fs);    return fd;}static intdo_close(diomsg * r, int len){    int fd;    file_state *fs;    fs = (file_state *) hash_lookup(hash, &r->id);    if (NULL == fs) {	errno = EBADF;	DEBUG(1) {	    fprintf(stderr, "%d CLOSE id %d: ", (int) mypid, r->id);	    perror("do_close");	}	return -errno;    }    fd = fs->fd;    hash_remove_link(hash, (hash_link *) fs);    DEBUG(2)	fprintf(stderr, "%d CLOSE id %d, FD %d, fs %p\n",	(int) mypid,	r->id,	fs->fd,	fs);    xfree(fs);    return close(fd);}static intdo_read(diomsg * r, int len, char *buf){    int x;    int readlen = r->size;    file_state *fs;    fs = (file_state *) hash_lookup(hash, &r->id);    if (NULL == fs) {	errno = EBADF;	DEBUG(1) {	    fprintf(stderr, "%d READ  id %d: ", (int) mypid, r->id);	    perror("do_read");	}	return -errno;    }    if (r->offset > -1 && r->offset != fs->offset) {	DEBUG(2)	    fprintf(stderr, "seeking to %" PRINTF_OFF_T "\n", (squid_off_t) r->offset);	if (lseek(fs->fd, r->offset, SEEK_SET) < 0) {	    DEBUG(1) {		fprintf(stderr, "%d FD %d, offset %" PRINTF_OFF_T ": ", (int) mypid, fs->fd, (squid_off_t) r->offset);		perror("lseek");	    }	}    }    x = read(fs->fd, buf, readlen);    DEBUG(2)	fprintf(stderr, "%d READ %d,%d,%" PRINTF_OFF_T " ret %d\n", (int) mypid,	fs->fd, readlen, (squid_off_t) r->offset, x);    if (x < 0) {	DEBUG(1) {	    fprintf(stderr, "%d FD %d: ", (int) mypid, fs->fd);	    perror("read");	}	return -errno;    }    fs->offset = r->offset + x;    return x;}static intdo_write(diomsg * r, int len, const char *buf){    int wrtlen = r->size;    int x;    file_state *fs;    fs = (file_state *) hash_lookup(hash, &r->id);    if (NULL == fs) {	errno = EBADF;	DEBUG(1) {	    fprintf(stderr, "%d WRITE id %d: ", (int) mypid, r->id);	    perror("do_write");	}	return -errno;    }    if (r->offset > -1 && r->offset != fs->offset) {	if (lseek(fs->fd, r->offset, SEEK_SET) < 0) {	    DEBUG(1) {		fprintf(stderr, "%d FD %d, offset %" PRINTF_OFF_T ": ", (int) mypid, fs->fd, (squid_off_t) r->offset);		perror("lseek");	    }	}    }    DEBUG(2)	fprintf(stderr, "%d WRITE %d,%d,%" PRINTF_OFF_T "\n", (int) mypid,	fs->fd, wrtlen, (squid_off_t) r->offset);    x = write(fs->fd, buf, wrtlen);    if (x < 0) {	DEBUG(1) {	    fprintf(stderr, "%d FD %d: ", (int) mypid, fs->fd);	    perror("write");	}	return -errno;    }    fs->offset = r->offset + x;    return x;}static intdo_unlink(diomsg * r, int len, const char *buf){#if USE_TRUNCATE    if (truncate(buf, 0) < 0)#else    if (unlink(buf) < 0)#endif    {	DEBUG(1) {	    fprintf(stderr, "%d UNLNK id %d %s: ", (int) mypid, r->id, buf);	    perror("truncate");	}	return -errno;    }    DEBUG(2)	fprintf(stderr, "%d UNLNK %s\n", (int) mypid, buf);    return 0;}static voidmsg_handle(diomsg * r, int rl, diomsg * s){    char *buf = NULL;    s->mtype = r->mtype;    s->id = r->id;    s->seq_no = r->seq_no;	/* optional, debugging */    s->callback_data = r->callback_data;    s->size = 0;		/* optional, debugging */    s->offset = 0;		/* optional, debugging */    s->shm_offset = r->shm_offset;    if (s->shm_offset > -1)	buf = shmbuf + s->shm_offset;    switch (r->mtype) {    case _MQD_OPEN:	s->status = do_open(r, rl, buf);	break;    case _MQD_CLOSE:	s->status = do_close(r, rl);	break;    case _MQD_READ:	s->status = do_read(r, rl, buf);	break;    case _MQD_WRITE:	s->status = do_write(r, rl, buf);	break;    case _MQD_UNLINK:	s->status = do_unlink(r, rl, buf);	break;    default:	assert(0);	break;    }}static intfsCmp(const void *a, const void *b){    const int *A = a;    const int *B = b;    return *A != *B;}static unsigned intfsHash(const void *key, unsigned int n){    /* note, n must be a power of 2! */    const int *k = key;    return (*k & (--n));}static voidalarm_handler(int sig){    (void) 0;}intmain(int argc, char *argv[]){    int key;    int rmsgid;    int smsgid;    int shmid;    diomsg rmsg;    diomsg smsg;    int rlen;    char rbuf[512];    struct sigaction sa;    setbuf(stdout, NULL);    setbuf(stderr, NULL);    mypid = getpid();    assert(4 == argc);    key = atoi(argv[1]);    rmsgid = msgget(key, 0600);    if (rmsgid < 0) {	perror("msgget");	return 1;    }    key = atoi(argv[2]);    smsgid = msgget(key, 0600);    if (smsgid < 0) {	perror("msgget");	return 1;    }    key = atoi(argv[3]);    shmid = shmget(key, 0, 0600);    if (shmid < 0) {	perror("shmget");	return 1;    }    shmbuf = shmat(shmid, NULL, 0);    if (shmbuf == (void *) -1) {	perror("shmat");	return 1;    }    hash = hash_create(fsCmp, 1 << 4, fsHash);    assert(hash);    fcntl(0, F_SETFL, SQUID_NONBLOCK);    memset(&sa, '\0', sizeof(sa));    sa.sa_handler = alarm_handler;    sa.sa_flags = SA_RESTART;    sigaction(SIGALRM, &sa, NULL);    for (;;) {	alarm(1);	memset(&rmsg, '\0', sizeof(rmsg));	rlen = msgrcv(rmsgid, &rmsg, msg_snd_rcv_sz, 0, 0);	if (rlen < 0) {	    if (EINTR == errno) {		if (read(0, rbuf, 512) <= 0) {		    if (EWOULDBLOCK == errno)			(void) 0;		    else if (EAGAIN == errno)			(void) 0;		    else			break;		}	    }	    if (EAGAIN == errno) {		continue;	    }	    perror("msgrcv");	    break;	}	alarm(0);	msg_handle(&rmsg, rlen, &smsg);	if (msgsnd(smsgid, &smsg, msg_snd_rcv_sz, 0) < 0) {	    perror("msgsnd");	    break;	}    }    DEBUG(2)	fprintf(stderr, "%d diskd exiting\n", (int) mypid);    if (msgctl(rmsgid, IPC_RMID, 0) < 0)	perror("msgctl IPC_RMID");    if (msgctl(smsgid, IPC_RMID, 0) < 0)	perror("msgctl IPC_RMID");    if (shmdt(shmbuf) < 0)	perror("shmdt");    if (shmctl(shmid, IPC_RMID, 0) < 0)	perror("shmctl IPC_RMID");    return 0;}