fetchmail.h

用于对收发邮件编码进行解码的类文件,功能简洁

/*
 * For license terms, see the file COPYING in this directory.
 */

/* We need this for HAVE_STDARG_H, etc */
#include "config.h"

/* constants designating the various supported protocols */
#define		P_AUTO		1
#define		P_POP2		2
#define		P_POP3		3
#define		P_IMAP		4
#define		P_IMAP_K4	5
#define		P_IMAP_GSS	6
#define		P_APOP		7
#define		P_RPOP		8
#define		P_ETRN		9

#if INET6
#define		SMTP_PORT	"smtp"
#define		KPOP_PORT	"kpop"
#else /* INET6 */
#define		SMTP_PORT	25
#define		KPOP_PORT	1109
#endif /* INET6 */

/* preauthentication types */
#define		A_PASSWORD	0	/* password or inline authentication */
#define		A_KERBEROS_V4	1	/* preauthenticate w/ Kerberos V4 */
#define		A_KERBEROS_V5	2	/* preauthenticate w/ Kerberos V5 */

/*
 * Definitions for buffer sizes.  We get little help on setting maxima
 * from IMAP RFCs up to 2060, so these are mostly from POP3.
 */
#define		HOSTLEN		635	/* max hostname length (RFC1123) */
#define		POPBUFSIZE	512	/* max length of response (RFC1939) */
#define		IDLEN		128	/* max length of UID (RFC1939) */

/* per RFC1939 this should be 40, but Microsoft Exchange ignores that limit */
#define		USERNAMELEN	128	/* max POP3 arg length */

/* clear a netBSD kernel parameter out of the way */ 
#undef		MSGBUFSIZE

/*
 * The RFC822 limit on message line size is just 998.  But
 * make this *way* oversized; idiot DOS-world mailers that
 * don't line-wrap properly often ship entire paragraphs as
 * lines.
 */
#define		MSGBUFSIZE	8192

#define		PASSWORDLEN	64	/* max password length */
#define		DIGESTLEN	33	/* length of MD5 digest */

/* exit code values */
#define		PS_SUCCESS	0	/* successful receipt of messages */
#define		PS_NOMAIL       1	/* no mail available */
#define		PS_SOCKET	2	/* socket I/O woes */
#define		PS_AUTHFAIL	3	/* user authorization failed */
#define		PS_PROTOCOL	4	/* protocol violation */
#define		PS_SYNTAX	5	/* command-line syntax error */
#define		PS_IOERR	6	/* bad permissions on rc file */
#define		PS_ERROR	7	/* protocol error */
#define		PS_EXCLUDE	8	/* client-side exclusion error */
#define		PS_LOCKBUSY	9	/* server responded lock busy */
#define		PS_SMTP         10      /* SMTP error */
#define		PS_DNS		11	/* fatal DNS error */
#define		PS_BSMTP	12	/* output batch could not be opened */
/* leave space for more codes */
#define		PS_UNDEFINED	23	/* something I hadn't thought of */
#define		PS_TRANSIENT	24	/* transient failure (internal use) */
#define		PS_REFUSED	25	/* mail refused (internal use) */
#define		PS_RETAINED	26	/* message retained (internal use) */
#define		PS_TRUNCATED	27	/* headers incomplete (internal use) */

/* output noise level */
#define         O_SILENT	0	/* mute, max squelch, etc. */
#define		O_NORMAL	1	/* user-friendly */
#define		O_VERBOSE	2	/* chatty */
#define		O_DEBUG		3	/* prolix */
#define		O_MONITOR	O_VERBOSE

#define		SIZETICKER	1024	/* print 1 dot per this many bytes */

/*
 * We #ifdef this and use flag rather than bool
 * to avoid a type clash with curses.h
 */
#ifndef TRUE
#define FALSE	0
#define TRUE	1
#endif /* TRUE */
typedef	char	flag;

/* we need to use zero as a flag-uninitialized value */
#define FLAG_TRUE	2
#define FLAG_FALSE	1

struct runctl
{
    char	*logfile;
    char	*idfile;
    int		poll_interval;
    flag	use_syslog;
    flag	invisible;
    char	*postmaster;
};

struct idlist
{
    char *id;
    union
    {
	struct
	{
	    short	num;
	    flag	mark;		/* UID-index information */
#define UID_UNSEEN	0		/* hasn't been seen */
#define UID_SEEN	1		/* seen, but not deleted */
#define UID_DELETED	2		/* this message has been deleted */
#define UID_EXPUNGED	3		/* this message has been expunged */ 
        }
	status;
	char *id2;
    } val;
    struct idlist *next;
};

struct query;

struct method		/* describe methods for protocol state machine */
{
    const char *name;		/* protocol name */
#if INET6
    const char *service;
#else /* INET6 */
    int	port;			/* service port */
#endif /* INET6 */
    flag tagged;		/* if true, generate & expect command tags */
    flag delimited;		/* if true, accept "." message delimiter */
    int (*parse_response)(int, char *);
				/* response_parsing function */
    int (*password_canonify)(char *, char *);
				/* canonicalize password */
    int (*getauth)(int, struct query *, char *);
				/* authorization fetcher */
    int (*getrange)(int, struct query *, const char *, int *, int *, int *);
				/* get message range to fetch */
    int (*getsizes)(int, int, int *);
				/* get sizes of messages */
    int (*is_old)(int, struct query *, int);
				/* check for old message */
    int (*fetch_headers)(int, struct query *, int, int *);
				/* fetch FROM headera given message */
    int (*fetch_body)(int, struct query *, int, int *);
				/* fetch a given message */
    int (*trail)(int, struct query *, int);
				/* eat trailer of a message */
    int (*delete)(int, struct query *, int);
				/* delete method */
    int (*logout_cmd)(int, struct query *);
				/* logout command */
    flag retry;			/* can getrange poll for new messages? */
};

struct hostdata		/* shared among all user connections to given server */
{
    /* rc file data */
    char *pollname;			/* poll label of host */
    char *via;				/* "true" server name if non-NULL */
    struct idlist *akalist;		/* server name first, then akas */
    struct idlist *localdomains;	/* list of pass-through domains */
    int protocol;			/* protocol type */
#if INET6
    char *service;			/* IPv6 service name */
    void *netsec;			/* IPv6 security request */
#else /* INET6 */
    int port;				/* TCP/IP service port number */
#endif /* INET6 */
    int interval;			/* # cycles to skip between polls */
    int preauthenticate;		/* preauthentication mode to try */
    int timeout;			/* inactivity timout in seconds */
    char *envelope;			/* envelope address list header */
    int envskip;			/* skip to numbered envelope header */
    char *qvirtual;			/* prefix removed from local user id */
    flag skip;				/* suppress poll in implicit mode? */
    flag dns;				/* do DNS lookup on multidrop? */
    flag uidl;				/* use RFC1725 UIDLs? */
#ifdef SDPS_ENABLE
    flag sdps;				/* use Demon Internet SDPS *ENV */
#endif /* SDPS_ENABLE */
    flag checkalias;                  	/* resolve aliases by comparing IPs? */


#ifdef linux
    char *interface;
    char *monitor;
    int  monitor_io;
    struct interface_pair_s *interface_pair;
#endif /* linux */

    char *plugin,*plugout;

    /* computed for internal use */
    const struct method *base_protocol;	/* relevant protocol method table */
    int poll_count;			/* count of polls so far */
    char *queryname;			/* name to attempt DNS lookup on */
    char *truename;			/* "true name" of server host */
    struct hostdata *lead_server;	/* ptr to lead query for this server */
    int esmtp_options;
};

struct query
{
    /* mailserver connection controls */
    struct hostdata server;

    /* per-user data */
    struct idlist *localnames;	/* including calling user's name */
    int wildcard;		/* should unmatched names be passed through */
    char *remotename;		/* remote login name to use */
    char *password;		/* remote password to use */
    struct idlist *mailboxes;	/* list of mailboxes to check */

    /* per-forwarding-target data */
    struct idlist *smtphunt;	/* list of SMTP hosts to try forwarding to */
    char *smtpaddress;		/* address to force in RCPT TO */ 
    struct idlist *antispam;	/* list of listener's antispam response */
    char *mda;			/* local MDA to pass mail to */
    char *bsmtp;		/* BSMTP output file */
    char listener;		/* what's the listener's wire protocol? */
#define SMTP_MODE	'S'
#define LMTP_MODE	'L'
    char *preconnect;		/* pre-connection command to execute */
    char *postconnect;		/* post-connection command to execute */

    /* per-user control flags */
    flag keep;			/* if TRUE, leave messages undeleted */
    flag fetchall;		/* if TRUE, fetch all (not just unseen) */
    flag flush;			/* if TRUE, delete messages already seen */
    flag rewrite;		/* if TRUE, canonicalize recipient addresses */
    flag stripcr;		/* if TRUE, strip CRs in text */
    flag forcecr;		/* if TRUE, force CRs before LFs in text */
    flag pass8bits;		/* if TRUE, ignore Content-Transfer-Encoding */
    flag dropstatus;		/* if TRUE, drop Status lines in mail */
    flag mimedecode;		/* if TRUE, decode MIME-armored messages */
    int	limit;			/* limit size of retrieved messages */
    int warnings;		/* size warning interval */
    int	fetchlimit;		/* max # msgs to get in single poll */
    int	batchlimit;		/* max # msgs to pass in single SMTP session */
    int	expunge;		/* max # msgs to pass between expunges */