article.c

早期freebsd实现

/*  $Revision: 1.13 $
**
**  Article-related routines.
*/
#include "nnrpd.h"


/*
**  Data structures for use in ARTICLE/HEAD/BODY/STAT common code.
*/
typedef enum _SENDTYPE {
    STarticle,
    SThead,
    STbody,
    STstat
} SENDTYPE;

typedef struct _SENDDATA {
    SENDTYPE	Type;
    int		ReplyCode;
    STRING	Item;
} SENDDATA;


/*
**  Information about the schema of the news overview files.
*/
typedef struct _ARTOVERFIELD {
    char	*Header;
    int		Length;
    BOOL	HasHeader;
} ARTOVERFIELD;


STATIC char		ARTnotingroup[] = NNTP_NOTINGROUP;
STATIC char		ARTnoartingroup[] = NNTP_NOARTINGRP;
STATIC char		ARTnocurrart[] = NNTP_NOCURRART;
STATIC QIOSTATE		*ARTqp;
STATIC ARTOVERFIELD	*ARTfields;
STATIC int		ARTfieldsize;
STATIC SENDDATA		SENDbody = {
    STbody,	NNTP_BODY_FOLLOWS_VAL,		"body"
};
STATIC SENDDATA		SENDarticle = {
    STarticle,	NNTP_ARTICLE_FOLLOWS_VAL,	"article"
};
STATIC SENDDATA		SENDstat = {
    STstat,	NNTP_NOTHING_FOLLOWS_VAL,	"status"
};
STATIC SENDDATA		SENDhead = {
    SThead,	NNTP_HEAD_FOLLOWS_VAL,		"head"
};


/*
**  Overview state information.
*/
STATIC QIOSTATE		*OVERqp;		/* Open overview file	*/
STATIC char		*OVERline;		/* Current line		*/
STATIC ARTNUM		OVERarticle;		/* Current article	*/
STATIC int		OVERopens;		/* Number of opens done	*/


/*
**  Read the overview schema.
*/
void
ARTreadschema()
{
    static char			SCHEMA[] = _PATH_SCHEMA;
    register FILE		*F;
    register char		*p;
    register ARTOVERFIELD	*fp;
    register int		i;
    char			buff[SMBUF];

    /* Open file, count lines. */
    if ((F = fopen(SCHEMA, "r")) == NULL)
	return;
    for (i = 0; fgets(buff, sizeof buff, F) != NULL; i++)
	continue;
    (void)fseek(F, (OFFSET_T)0, SEEK_SET);
    ARTfields = NEW(ARTOVERFIELD, i + 1);

    /* Parse each field. */
    for (fp = ARTfields; fgets(buff, sizeof buff, F) != NULL; ) {
	/* Ignore blank and comment lines. */
	if ((p = strchr(buff, '\n')) != NULL)
	    *p = '\0';
	if ((p = strchr(buff, COMMENT_CHAR)) != NULL)
	    *p = '\0';
	if (buff[0] == '\0')
	    continue;
	if ((p = strchr(buff, ':')) != NULL) {
	    *p++ = '\0';
	    fp->HasHeader = EQ(p, "full");
	}
	else
	    fp->HasHeader = FALSE;
	fp->Header = COPY(buff);
	fp->Length = strlen(buff);
	fp++;
    }
    ARTfieldsize = fp - ARTfields;
    (void)fclose(F);
}


/*
**  If we have an article open, close it.
*/
void
ARTclose()
{
    if (ARTqp) {
	QIOclose(ARTqp);
	ARTqp = NULL;
    }
}


/*
**  Get the Message-ID from a file.
*/
STATIC void
ARTgetmsgid(qp, id)
    register QIOSTATE	*qp;
    char		*id;
{
    register char	*p;
    register char	*q;

    for (*id = '\0'; (p = QIOread(qp)) != NULL && *p != '\0'; ) {
	if (*p != 'M' && *p != 'm')
	    continue;
	if ((q = strchr(p, ' ')) == NULL)
	    continue;
	*q++ = '\0';
	if (caseEQ(p, "Message-ID:")) {
	    (void)strcpy(id, q);
	    break;
	}
    }
    (void)QIOrewind(qp);
}


/*
**  If the article name is valid, open it and stuff in the ID.
*/
STATIC BOOL
ARTopen(name, id)
    char		*name;
    char		*id;
{
    static ARTNUM	save_artnum;
    static char		save_artid[BIG_BUFFER];
    struct stat		Sb;

    /* Re-use article if it's the same one. */
    if (ARTqp != NULL) {
	if (save_artnum == atol(name) && QIOrewind(ARTqp) != -1) {
	    if (id)
		(void)strcpy(id, save_artid);
	    return TRUE;
	}
	QIOclose(ARTqp);
    }

    /* Open it, make sure it's a regular file. */
    if ((ARTqp = QIOopen(name, QIO_BUFFER)) == NULL)
	return FALSE;
    if (fstat(QIOfileno(ARTqp), &Sb) < 0 || !S_ISREG(Sb.st_mode)) {
	QIOclose(ARTqp);
	ARTqp = NULL;
	return FALSE;
    }
    CloseOnExec(QIOfileno(ARTqp), TRUE);

    save_artnum = atol(name);
    ARTgetmsgid(ARTqp, save_artid);
    (void)strcpy(id, save_artid);
    return TRUE;
}


/*
**  Open the article for a given Message-ID.
*/
STATIC QIOSTATE *
ARTopenbyid(msg_id, ap)
    char	*msg_id;
    ARTNUM	*ap;
{
    QIOSTATE	*qp;
    char	*p;
    char	*q;

    *ap = 0;
    if ((p = HISgetent(msg_id, FALSE)) == NULL)
	return NULL;
    if ((qp = QIOopen(p, QIO_BUFFER)) == NULL)
	return NULL;
    CloseOnExec(QIOfileno(qp), TRUE);
    if ((q = strrchr(p, '/')) != NULL)
	*q++ = '\0';
    if (GRPlast[0] && EQ(p, GRPlast))
	*ap = atol(q);
    return qp;
}


/*
**  Send a (part of) a file to stdout, doing newline and dot conversion.
*/
STATIC void
ARTsend(qp, what)
    register QIOSTATE	*qp;
    SENDTYPE		what;
{
    register char	*p;

    ARTcount++;
    GRParticles++;

    /* Get the headers. */
    for ( ; ; ) {
	p = QIOread(qp);
	if (p == NULL) {
	    if (QIOtoolong(qp))
		continue;
	    break;
	}
	if (*p == '\0')
	    break;
	if (what == STbody)
	    continue;
	Printf("%s%s\r\n", *p == '.' ? "." : "", p);
    }

    if (what == SThead) {
	Printf(".\r\n");
	return;
    }

    if (what == STarticle)
	Printf("\r\n");
    for ( ; ; ) {
	p = QIOread(qp);
	if (p == NULL) {
	    if (QIOtoolong(qp))
		continue;
	    break;
	}
	Printf("%s%s\r\n", *p == '.' ? "." : "", p);
    }
    Printf(".\r\n");
}


/*
**  Find an article number in the article array via a binary search;
**  return -1 if not found.  Cache last hit to make linear lookups
**  faster.
*/
STATIC int
ARTfind(i)
    register ARTNUM	i;
{
    register ARTNUM	*bottom;
    register ARTNUM	*middle;
    register ARTNUM	*top;

    if (ARTsize == 0)
	return -1;

    top = &ARTnumbers[ARTsize - 1];
    if (ARTcache && ++ARTcache <= top && *ARTcache <= i) {
	if (*ARTcache == i)
	    return ARTcache - ARTnumbers;
	bottom = ARTcache;
    }
    else {
	ARTcache = NULL;
	bottom = ARTnumbers;
    }

    for ( ; ; ) {
	if (i < *bottom || i > *top)
	    break;

	middle = bottom + (top - bottom) / 2;
	if (i == *middle) {
	    /* Found it; update cache. */
	    ARTcache = middle;
	    return middle - ARTnumbers;
	}

	if (i > *middle)
	    bottom = middle + 1;
	else
	    top = middle;
    }
    return -1;
}


/*
**  Ask the innd server for the article.  Only called from CMDfetch,
**  and only if history file is buffered.  Common case:  "oops, cancel
**  that article I just posted."
*/
STATIC QIOSTATE *
ARTfromboss(what, id)
    SENDDATA		*what;
    char		*id;
{
    FILE		*FromServer;
    FILE		*ToServer;
    QIOSTATE		*qp;
    char		buff[NNTP_STRLEN + 2];
    char		*name;
    char		*p;
    BOOL		more;

    /* If we can, open the connection. */
    if (NNTPlocalopen(&FromServer, &ToServer, (char *)NULL) < 0)
	return NULL;

    /* Send the query to the server. */
    qp = NULL;
    (void)fprintf(ToServer, "XPATH %s\r\n", id);
    (void)fflush(ToServer);
    if (ferror(ToServer))
	goto QuitClose;

    /* Get the reply; article exist? */
    if (fgets(buff, sizeof buff, FromServer) == NULL
     || atoi(buff) == NNTP_DONTHAVEIT_VAL)
	goto QuitClose;

    /* Yes.  Be quick if just doing a stat. */
    if (what == &SENDstat) {
	qp = QIOopen("/dev/null", 0);
	goto QuitClose;
    }

    /* Clean up response. */
    if ((p = strchr(buff, '\r')) != NULL)
	*p = '\0';
    if ((p = strchr(buff, '\n')) != NULL)
	*p = '\0';

    /* Loop over all filenames until we can open one. */
    for (name = buff; *name; name = p + 1) {
	/* Snip off next name, turn dots to slashes. */
	for (p = name; ISWHITE(*p); p++)
	    continue;
	for (name = p; *p && *p != ' '; p++)
	    if (*p == '.')
		*p = '/';
	more = *p == ' ';
	if (more)
	    *p = '\0';
	if ((qp = QIOopen(name, QIO_BUFFER)) != NULL || !more)
	    break;
    }

    /* Send quit, read server's reply, close up and return. */
  QuitClose:
    (void)fprintf(ToServer, "quit\r\n");
    (void)fclose(ToServer);
    (void)fgets(buff, sizeof buff, FromServer);
    (void)fclose(FromServer);
    return qp;
}


/*
**  Fetch part or all of an article and send it to the client.
*/
FUNCTYPE
CMDfetch(ac, av)
    int			ac;
    char		*av[];
{
    char		buff[SMBUF];
    char		idbuff[BIG_BUFFER];
    SENDDATA		*what;
    register QIOSTATE	*qp;
    register BOOL	ok;
    ARTNUM		art;

    /* Find what to send; get permissions. */
    ok = PERMcanread;
    switch (*av[0]) {
    default:
	what = &SENDbody;
	break;
    case 'a': case 'A':
	what = &SENDarticle;
	break;
    case 's': case 'S':
	what = &SENDstat;
	break;
    case 'h': case 'H':
	what = &SENDhead;
	/* Poster might do a "head" command to verify the article. */
	ok = PERMcanread || PERMcanpost;
	break;
    }

    if (!ok) {
	Reply("%s\r\n", NOACCESS);
	return;
    }

    /* Requesting by Message-ID? */
    if (ac == 2 && av[1][0] == '<') {
	if ((qp = ARTopenbyid(av[1], &art)) == NULL
	 && (qp = ARTfromboss(what, av[1])) == NULL) {
	    Reply("%d No such article\r\n", NNTP_DONTHAVEIT_VAL);
	    return;
	}
	if (!PERMartok(qp)) {
	    QIOclose(qp);
	    Reply("%s\r\n", NOACCESS);
	    return;
	}
	Reply("%d %ld %s %s\r\n", what->ReplyCode, art, what->Item, av[1]);
	if (what->Type != STstat)
	    ARTsend(qp, what->Type);
	QIOclose(qp);
	return;
    }

    /* Trying to read. */
    if (GRPcount == 0) {
	Reply("%s\r\n", ARTnotingroup);
	return;
    }

    /* Default is to get current article, or specified article. */
    if (ac == 1) {
	if (ARTindex < 0 || ARTindex >= ARTsize) {
	    Reply("%s\r\n", ARTnocurrart);
	    return;
	}
	(void)sprintf(buff, "%ld", ARTnumbers[ARTindex]);
    }
    else {
	if (strspn(av[1], "0123456789") != strlen(av[1])) {
	    Reply("%s\r\n", ARTnoartingroup);
	    return;
	}
	(void)strcpy(buff, av[1]);
    }

    /* Move forward until we can find one. */
    while (!ARTopen(buff, idbuff)) {
	if (ac > 1 || ++ARTindex >= ARTsize) {
	    Reply("%s\r\n", ARTnoartingroup);
	    return;
	}
	(void)sprintf(buff, "%ld", ARTnumbers[ARTindex]);
    }

    Reply("%d %s %s %s\r\n", what->ReplyCode, buff, idbuff, what->Item);
    if (what->Type != STstat)
	ARTsend(ARTqp, what->Type);
    if (ac > 1)
	ARTindex = ARTfind((ARTNUM)atol(buff));
}


/*
**  Go to the next or last (really previous) article in the group.
*/
FUNCTYPE
CMDnextlast(ac, av)
    int		ac;
    char	*av[];
{
    char	buff[SPOOLNAMEBUFF];
    char	idbuff[SMBUF];
    int		save;
    BOOL	next;
    int		delta;
    int		errcode;
    STRING	message;

    if (!PERMcanread) {
	Reply("%s\r\n", NOACCESS);
	return;
    }
    if (GRPcount == 0) {
	Reply("%s\r\n", ARTnotingroup);
	return;
    }
    if (ARTindex < 0 || ARTindex >= ARTsize) {
	Reply("%s\r\n", ARTnocurrart);
	return;
    }

    next = (av[0][0] == 'n' || av[0][0] == 'N');
    if (next) {
	delta = 1;
	errcode = NNTP_NONEXT_VAL;
	message = "next";
    }
    else {
	delta = -1;
	errcode = NNTP_NOPREV_VAL;
	message = "previous";
    }

    save = ARTindex;
    ARTindex += delta;
    if (ARTindex < 0 || ARTindex >= ARTsize) {
	Reply("%d No %s to retrieve.\r\n", errcode, message);
	ARTindex = save;
	return;
    }

    (void)sprintf(buff, "%ld", ARTnumbers[ARTindex]);
    while (!ARTopen(buff, idbuff)) {
	ARTindex += delta;
	if (ARTindex < 0 || ARTindex >= ARTsize) {
	    Reply("%d No %s article to retrieve.\r\n", errcode, message);
	    ARTindex = save;
	    return;
	}
	(void)sprintf(buff, "%ld", ARTnumbers[ARTindex]);
    }

    Reply("%d %s %s Article retrieved; request text separately.\r\n",
	   NNTP_NOTHING_FOLLOWS_VAL, buff, idbuff);

    if (ac > 1)
	ARTindex = ARTfind((ARTNUM)atol(buff));
}


/*
**  Return the header from the specified file, or NULL if not found.
**  We can estimate the Lines header, if that's what's wanted.
*/
STATIC char *
GetHeader(qp, header, IsLines)
    register QIOSTATE	*qp;
    register char	*header;
    BOOL		IsLines;
{
    static char		buff[40];
    register char	*p;