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#include <u.h>
#include <libc.h>
#include <bio.h>
#include <ndb.h>
#include <fcall.h>
#include <thread.h>
#include <9p.h>
#include <ctype.h>
#include "dat.h"
#include "fns.h"

int cookiedebug;

typedef struct Cookie Cookie;
typedef struct Jar Jar;

struct Cookie
{
        /* external info */
        char*   name;
        char*   value;
        char*   dom;            /* starts with . */
        char*   path;
        char*   version;
        char*   comment;                /* optional, may be nil */

        uint            expire;         /* time of expiration: ~0 means when webcookies dies */
        int             secure;
        int             explicitdom;    /* dom was explicitly set */
        int             explicitpath;   /* path was explicitly set */
        int             netscapestyle;

        /* internal info */
        int             deleted;
        int             mark;
        int             ondisk;
};

struct Jar
{
        Cookie  *c;
        int             nc;
        int             mc;

        Qid             qid;
        int             dirty;
        char            *file;
        char            *lockfile;
};

struct {
        char *s;
        int     offset;
        int     ishttp;
} stab[] = {
        "domain",               offsetof(Cookie, dom),          1,
        "path",         offsetof(Cookie, path),         1,
        "name",         offsetof(Cookie, name),         0,
        "value",                offsetof(Cookie, value),                0,
        "comment",      offsetof(Cookie, comment),      1,
        "version",              offsetof(Cookie, version),              1,
};

struct {
        char *s;
        int     offset;
} itab[] = {
        "expire",                       offsetof(Cookie, expire),
        "secure",                       offsetof(Cookie, secure),
        "explicitdomain",       offsetof(Cookie, explicitdom),
        "explicitpath",         offsetof(Cookie, explicitpath),
        "netscapestyle",        offsetof(Cookie, netscapestyle),
};

#pragma varargck type "J"       Jar*
#pragma varargck type "K"       Cookie*

/* HTTP format */
static int
jarfmt(Fmt *fp)
{
        int i;
        Jar *jar;

        jar = va_arg(fp->args, Jar*);

        if(jar == nil || jar->nc == 0)
                return 0;

        fmtstrcpy(fp, "Cookie: ");
        if(jar->c[0].version)
                fmtprint(fp, "$Version=%s; ", jar->c[0].version);
        for(i=0; i<jar->nc; i++)
                fmtprint(fp, "%s%s=%s", i ? "; ": "", jar->c[i].name, jar->c[i].value);
        fmtstrcpy(fp, "\r\n");
        return 0;
}

/* individual cookie */
static int
cookiefmt(Fmt *fp)
{
        int j, k, first;
        char *t;
        Cookie *c;

        c = va_arg(fp->args, Cookie*);

        first = 1;
        for(j=0; j<nelem(stab); j++){
                t = *(char**)((uintptr)c+stab[j].offset);
                if(t == nil)
                        continue;
                if(first)
                        first = 0;
                else
                        fmtstrcpy(fp, " ");
                fmtprint(fp, "%s=%q", stab[j].s, t);
        }
        for(j=0; j<nelem(itab); j++){
                k = *(int*)((uintptr)c+itab[j].offset);
                if(k == 0)
                        continue;
                if(first)
                        first = 0;
                else
                        fmtstrcpy(fp, " ");
                fmtprint(fp, "%s=%ud", itab[j].s, k);
        }
        return 0;
}

/*
 * sort cookies:
 *      - alpha by name
 *      - alpha by domain
 *      - longer paths first, then alpha by path (RFC2109 4.3.4)
 */
static int
cookiecmp(Cookie *a, Cookie *b)
{
        int i;

        if((i = strcmp(a->name, b->name)) != 0)
                return i;
        if((i = cistrcmp(a->dom, b->dom)) != 0)
                return i;
        if((i = strlen(b->path) - strlen(a->path)) != 0)
                return i;
        if((i = strcmp(a->path, b->path)) != 0)
                return i;
        return 0;
}

static int
exactcookiecmp(Cookie *a, Cookie *b)
{
        int i;

        if((i = cookiecmp(a, b)) != 0)
                return i;
        if((i = strcmp(a->value, b->value)) != 0)
                return i;
        if(a->version || b->version){
                if(!a->version)
                        return -1;
                if(!b->version)
                        return 1;
                if((i = strcmp(a->version, b->version)) != 0)
                        return i;
        }
        if(a->comment || b->comment){
                if(!a->comment)
                        return -1;
                if(!b->comment)
                        return 1;
                if((i = strcmp(a->comment, b->comment)) != 0)
                        return i;
        }
        if((i = b->expire - a->expire) != 0)
                return i;
        if((i = b->secure - a->secure) != 0)
                return i;
        if((i = b->explicitdom - a->explicitdom) != 0)
                return i;
        if((i = b->explicitpath - a->explicitpath) != 0)
                return i;
        if((i = b->netscapestyle - a->netscapestyle) != 0)
                return i;

        return 0;
}

static void
freecookie(Cookie *c)
{
        int i;

        for(i=0; i<nelem(stab); i++)
                free(*(char**)((uintptr)c+stab[i].offset));
}

static void
copycookie(Cookie *c)
{
        int i;
        char **ps;

        for(i=0; i<nelem(stab); i++){
                ps = (char**)((uintptr)c+stab[i].offset);
                if(*ps)
                        *ps = estrdup9p(*ps);
        }
}

static void
delcookie(Jar *j, Cookie *c)
{
        int i;

        j->dirty = 1;
        i = c - j->c;
        if(i < 0 || i >= j->nc)
                abort();
        c->deleted = 1;
}

static void
addcookie(Jar *j, Cookie *c)
{
        int i;

        if(!c->name || !c->value || !c->path || !c->dom){
                fprint(2, "not adding incomplete cookie\n");
                return;
        }

        if(cookiedebug)
                fprint(2, "add %K\n", c);

        for(i=0; i<j->nc; i++)
                if(cookiecmp(&j->c[i], c) == 0){
                        if(cookiedebug)
                                fprint(2, "cookie %K matches %K\n", &j->c[i], c);
                        if(exactcookiecmp(&j->c[i], c) == 0){
                                if(cookiedebug)
                                        fprint(2, "\texactly\n");
                                j->c[i].mark = 0;
                                return;
                        }
                        delcookie(j, &j->c[i]);
                }

        j->dirty = 1;
        if(j->nc == j->mc){
                j->mc += 16;
                j->c = erealloc9p(j->c, j->mc*sizeof(Cookie));
        }
        j->c[j->nc] = *c;
        copycookie(&j->c[j->nc]);
        j->nc++;
}

static void
purgejar(Jar *j)
{
        int i;

        for(i=j->nc-1; i>=0; i--){
                if(!j->c[i].deleted)
                        continue;
                freecookie(&j->c[i]);
                --j->nc;
                j->c[i] = j->c[j->nc];
        }
}

static void
addtojar(Jar *jar, char *line, int ondisk)
{
        Cookie c;
        int i, j, nf, *pint;
        char *f[20], *attr, *val, **pstr;
        
        memset(&c, 0, sizeof c);
        c.expire = ~0;
        c.ondisk = ondisk;
        nf = tokenize(line, f, nelem(f));
        for(i=0; i<nf; i++){
                attr = f[i];
                if((val = strchr(attr, '=')) != nil)
                        *val++ = '\0';
                else
                        val = "";
                /* string attributes */
                for(j=0; j<nelem(stab); j++){
                        if(strcmp(stab[j].s, attr) == 0){
                                pstr = (char**)((uintptr)&c+stab[j].offset);
                                *pstr = val;
                        }
                }
                /* integer attributes */
                for(j=0; j<nelem(itab); j++){
                        if(strcmp(itab[j].s, attr) == 0){
                                pint = (int*)((uintptr)&c+itab[j].offset);
                                if(val[0]=='\0')
                                        *pint = 1;
                                else
                                        *pint = strtoul(val, 0, 0);
                        }
                }
        }
        if(c.name==nil || c.value==nil || c.dom==nil || c.path==nil){
                if(cookiedebug)
                        fprint(2, "ignoring fractional cookie %K\n", &c);
                return;
        }
        addcookie(jar, &c);
}

static Jar*
newjar(void)
{
        Jar *jar;

        jar = emalloc9p(sizeof(Jar));
        return jar;
}

static int
expirejar(Jar *jar, int exiting)
{
        int i, n;
        uint now;

        now = time(0);
        n = 0;
        for(i=0; i<jar->nc; i++){
                if(jar->c[i].expire < now || (exiting && jar->c[i].expire==~0)){
                        delcookie(jar, &jar->c[i]);
                        n++;
                }
        }
        return n;
}

static void
dumpjar(Jar *jar, char *desc)
{
        int i;
        Biobuf *b;
        char *s;

        print("%s\n", desc);
        print("\tin memory:\n");
        
        for(i=0; i<jar->nc; i++)
                print("\t%K%s%s%s\n", &jar->c[i],
                        jar->c[i].ondisk ? " ondisk" : "",
                        jar->c[i].deleted ? " deleted" : "",
                        jar->c[i].mark ? " mark" : "");
        print("\n\ton disk:\n");
        if((b = Bopen(jar->file, OREAD)) == nil){
                print("\tno file\n");
        }else{
                while((s = Brdstr(b, '\n', 1)) != nil){
                        print("\t%s\n", s);
                        free(s);
                }
                Bterm(b);
        }
        print("\n");
}

static int
syncjar(Jar *jar)
{
        int i, fd;
        char *line;
        Dir *d;
        Biobuf *b;
        Qid q;

        if(jar->file==nil)
                return 0;

        memset(&q, 0, sizeof q);
        if((d = dirstat(jar->file)) != nil){
                q = d->qid;
                if(d->qid.path != jar->qid.path || d->qid.vers != jar->qid.vers)
                        jar->dirty = 1;
                free(d);
        }

        if(jar->dirty == 0)
                return 0;

        fd = -1;
        for(i=0; i<50; i++){
                if((fd = create(jar->lockfile, OWRITE, DMEXCL|0666)) < 0){
                        sleep(100);
                        continue;
                }
                break;
        }
        if(fd < 0){
                if(cookiedebug)
                        fprint(2, "open %s: %r", jar->lockfile);
                werrstr("cannot acquire jar lock: %r");
                return -1;
        }

        for(i=0; i<jar->nc; i++)        /* mark is cleared by addcookie */
                jar->c[i].mark = jar->c[i].ondisk;

        if((b = Bopen(jar->file, OREAD)) == nil){
                if(cookiedebug)
                        fprint(2, "Bopen %s: %r", jar->file);
                werrstr("cannot read cookie file %s: %r", jar->file);
                close(fd);
                return -1;
        }
        for(; (line = Brdstr(b, '\n', 1)) != nil; free(line)){
                if(*line == '#')
                        continue;
                addtojar(jar, line, 1);
        }
        Bterm(b);

        for(i=0; i<jar->nc; i++)
                if(jar->c[i].mark && jar->c[i].expire != ~0)
                        delcookie(jar, &jar->c[i]);

        purgejar(jar);

        b = Bopen(jar->file, OWRITE);
        if(b == nil){
                if(cookiedebug)
                        fprint(2, "Bopen write %s: %r", jar->file);
                close(fd);
                return -1;
        }
        Bprint(b, "# webcookies cookie jar\n");
        Bprint(b, "# comments and non-standard fields will be lost\n");
        for(i=0; i<jar->nc; i++){
                if(jar->c[i].expire == ~0)
                        continue;
                Bprint(b, "%K\n", &jar->c[i]);
                jar->c[i].ondisk = 1;
        }
        Bterm(b);

        jar->dirty = 0;
        close(fd);
        if((d = dirstat(jar->file)) != nil){
                jar->qid = d->qid;
                free(d);
        }
        return 0;
}

static Jar*
readjar(char *file)
{
        char *lock, *p;
        Jar *jar;

        jar = newjar();
        lock = emalloc9p(strlen(file)+10);
        strcpy(lock, file);
        if((p = strrchr(lock, '/')) != nil)
                p++;
        else
                p = lock;
        memmove(p+2, p, strlen(p)+1);
        p[0] = 'L';
        p[1] = '.';
        jar->lockfile = lock;
        jar->file = file;
        jar->dirty = 1;

        if(syncjar(jar) < 0){
                free(jar->file);
                free(jar->lockfile);
                free(jar);
                return nil;
        }
        return jar;
}

static void
closejar(Jar *jar)
{
        int i;

        if(jar == nil)
                return;
        expirejar(jar, 0);
        if(syncjar(jar) < 0)
                fprint(2, "warning: cannot rewrite cookie jar: %r\n");

        for(i=0; i<jar->nc; i++)
                freecookie(&jar->c[i]);

        free(jar->file);
        free(jar);      
}

/*
 * Domain name matching is per RFC2109, section 2:
 *
 * Hosts names can be specified either as an IP address or a FQHN
 * string.  Sometimes we compare one host name with another.  Host A's
 * name domain-matches host B's if
 *
 * * both host names are IP addresses and their host name strings match
 *   exactly; or
 *
 * * both host names are FQDN strings and their host name strings match
 *   exactly; or
 *
 * * A is a FQDN string and has the form NB, where N is a non-empty name
 *   string, B has the form .B', and B' is a FQDN string.  (So, x.y.com
 *   domain-matches .y.com but not y.com.)
 *
 * Note that domain-match is not a commutative operation: a.b.c.com
 * domain-matches .c.com, but not the reverse.
 *
 * (This does not verify that IP addresses and FQDN's are well-formed.)
 */
static int
isdomainmatch(char *name, char *pattern)
{
        int lname, lpattern;

        if(cistrcmp(name, pattern)==0)
                return 1;

        if(strcmp(ipattr(name), "dom")==0 && pattern[0]=='.'){
                lname = strlen(name);
                lpattern = strlen(pattern);
                /* e.g., name: www.google.com && pattern: .google.com */
                if(lname >= lpattern && cistrcmp(name+lname-lpattern, pattern)==0)
                        return 1;
                /* e.g., name: google.com && pattern: .google.com */
                if(lpattern > lname &&
                    cistrcmp(pattern+lpattern-lname, name) == 0)
                        return 1;
        }
        return 0;
}

/*
 * RFC2109 4.3.4:
 *      - domain must match
 *      - path in cookie must be a prefix of request path
 *      - cookie must not have expired
 */
static int
iscookiematch(Cookie *c, char *dom, char *path, uint now)
{
        return isdomainmatch(dom, c->dom)
                && strncmp(c->path, path, strlen(c->path))==0
                && (c->expire == 0 || c->expire >= now);
}

/* 
 * Produce a subjar of matching cookies.
 * Secure cookies are only included if secure is set.
 */
static Jar*
cookiesearch(Jar *jar, char *dom, char *path, int issecure)
{
        int i;
        Jar *j;
        uint now;

        if(cookiedebug)
                fprint(2, "cookiesearch %s %s %d\n", dom, path, issecure);
        now = time(0);
        j = newjar();
        for(i=0; i<jar->nc; i++){
                if(cookiedebug)
                        fprint(2, "\ttry %s %s %d %s\n", jar->c[i].dom,
                                jar->c[i].path, jar->c[i].secure,
                                jar->c[i].name);
                if((issecure || !jar->c[i].secure) &&
                    iscookiematch(&jar->c[i], dom, path, now)){
                        if(cookiedebug)
                                fprint(2, "\tmatched\n");
                        addcookie(j, &jar->c[i]);
                }
        }
        if(j->nc == 0){
                closejar(j);
                werrstr("no cookies found");
                return nil;
        }
        qsort(j->c, j->nc, sizeof(j->c[0]), (int(*)(void*, void*))cookiecmp);
        return j;
}

/*
 * RFC2109 4.3.2 security checks
 */
static char*
isbadcookie(Cookie *c, char *dom, char *path)
{
        int lcdom, ldom;

        if(strncmp(c->path, path, strlen(c->path)) != 0)
                return "cookie path is not a prefix of the request path";

        /*
         * fgb says omitting this test is necessary to get some sites to work,
         * but it seems dubious.
         */
        if(c->explicitdom && c->dom[0] != '.')
                return "cookie domain doesn't start with dot";

        lcdom = strlen(c->dom);
        if(memchr(c->dom+1, '.', lcdom-1-1) == nil)
                return "cookie domain doesn't have embedded dots";

        if(!isdomainmatch(dom, c->dom))
                return "request host does not match cookie domain";

        ldom = strlen(dom);
        if(strcmp(ipattr(dom), "dom")==0 && lcdom > ldom &&
            memchr(dom, '.', lcdom - ldom) != nil)
                return "request host contains dots before cookie domain";

        return 0;
}

/*
 * Sunday, 25-Jan-2002 12:24:36 GMT
 * Sunday, 25 Jan 2002 12:24:36 GMT
 * Sun, 25 Jan 02 12:24:36 GMT
 */
static int
isleap(int year)
{
        return year%4==0 && (year%100!=0 || year%400==0);
}

static uint
strtotime(char *s)
{
        char *os;
        int i;
        Tm tm;

        static int mday[2][12] = {
                31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31,
                31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31,
        };
        static char *wday[] = {
                "Sunday", "Monday", "Tuesday", "Wednesday",
                "Thursday", "Friday", "Saturday",
        };
        static char *mon[] = {
                "Jan", "Feb", "Mar", "Apr", "May", "Jun",
                "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
        };

        os = s;
        /* Sunday, */
        for(i=0; i<nelem(wday); i++){
                if(cistrncmp(s, wday[i], strlen(wday[i])) == 0){
                        s += strlen(wday[i]);
                        break;
                }
                if(cistrncmp(s, wday[i], 3) == 0){
                        s += 3;
                        break;
                }
        }
        if(i==nelem(wday)){
                if(cookiedebug)
                        fprint(2, "bad wday (%s)\n", os);
                return -1;
        }
        if(*s++ != ',' || *s++ != ' '){
                if(cookiedebug)
                        fprint(2, "bad wday separator (%s)\n", os);
                return -1;
        }

        /* 25- */
        if(!isdigit(s[0]) || !isdigit(s[1]) || (s[2]!='-' && s[2]!=' ')){
                if(cookiedebug)
                        fprint(2, "bad day of month (%s)\n", os);
                return -1;
        }
        tm.mday = strtol(s, 0, 10);
        s += 3;

        /* Jan- */
        for(i=0; i<nelem(mon); i++)
                if(cistrncmp(s, mon[i], 3) == 0){
                        tm.mon = i;
                        s += 3;
                        break;
                }
        if(i==nelem(mon)){
                if(cookiedebug)
                        fprint(2, "bad month (%s)\n", os);
                return -1;
        }
        if(s[0] != '-' && s[0] != ' '){
                if(cookiedebug)
                        fprint(2, "bad month separator (%s)\n", os);
                return -1;
        }
        s++;

        /* 2002 */
        if(!isdigit(s[0]) || !isdigit(s[1])){
                if(cookiedebug)
                        fprint(2, "bad year (%s)\n", os);
                return -1;
        }
        tm.year = strtol(s, 0, 10);
        s += 2;
        if(isdigit(s[0]) && isdigit(s[1]))
                s += 2;
        else{
                if(tm.year <= 68)
                        tm.year += 2000;
                else
                        tm.year += 1900;
        }
        if(tm.mday==0 || tm.mday > mday[isleap(tm.year)][tm.mon]){
                if(cookiedebug)
                        fprint(2, "invalid day of month (%s)\n", os);
                return -1;
        }
        tm.year -= 1900;
        if(*s++ != ' '){
                if(cookiedebug)
                        fprint(2, "bad year separator (%s)\n", os);
                return -1;
        }

        if(!isdigit(s[0]) || !isdigit(s[1]) || s[2]!=':'
        || !isdigit(s[3]) || !isdigit(s[4]) || s[5]!=':'
        || !isdigit(s[6]) || !isdigit(s[7]) || s[8]!=' '){
                if(cookiedebug)
                        fprint(2, "bad time (%s)\n", os);
                return -1;
        }

        tm.hour = atoi(s);
        tm.min = atoi(s+3);
        tm.sec = atoi(s+6);
        if(tm.hour >= 24 || tm.min >= 60 || tm.sec >= 60){
                if(cookiedebug)
                        fprint(2, "invalid time (%s)\n", os);
                return -1;
        }
        s += 9;

        if(cistrcmp(s, "GMT") != 0){
                if(cookiedebug)
                        fprint(2, "time zone not GMT (%s)\n", os);
                return -1;
        }
        strcpy(tm.zone, "GMT");
        tm.yday = 0;
        return tm2sec(&tm);
}

/*
 * skip linear whitespace.  we're a bit more lenient than RFC2616 2.2.
 */
static char*
skipspace(char *s)
{
        while(*s=='\r' || *s=='\n' || *s==' ' || *s=='\t')
                s++;
        return s;
}

/*
 * Try to identify old netscape headers.
 * The old headers:
 *      - didn't allow spaces around the '='
 *      - used an 'Expires' attribute
 *      - had no 'Version' attribute
 *      - had no quotes
 *      - allowed whitespace in values
 *      - apparently separated attr/value pairs with ';' exclusively
 */
static int
isnetscape(char *hdr)
{
        char *s;

        for(s=hdr; (s=strchr(s, '=')) != nil; s++){
                if(isspace(s[1]) || (s > hdr && isspace(s[-1])))
                        return 0;
                if(s[1]=='"')
                        return 0;
        }
        if(cistrstr(hdr, "version="))
                return 0;
        return 1;
}

/*
 * Parse HTTP response headers, adding cookies to jar.
 * Overwrites the headers.  May overwrite path.
 */
static char* parsecookie(Cookie*, char*, char**, int, char*, char*);
static int
parsehttp(Jar *jar, char *hdr, char *dom, char *path)
{
        static char setcookie[] = "Set-Cookie:";
        char *e, *p, *nextp;
        Cookie c;
        int isns, n;

        isns = isnetscape(hdr);
        n = 0;
        for(p=hdr; p; p=nextp){
                p = skipspace(p);
                if(*p == '\0')
                        break;
                nextp = strchr(p, '\n');
                if(nextp != nil)
                        *nextp++ = '\0';
                if(cistrncmp(p, setcookie, strlen(setcookie)) != 0)
                        continue;
                if(cookiedebug)
                        fprint(2, "%s\n", p);
                p = skipspace(p+strlen(setcookie));
                for(; *p; p=skipspace(p)){
                        if((e = parsecookie(&c, p, &p, isns, dom, path)) != nil){
                                if(cookiedebug)
                                        fprint(2, "parse cookie: %s\n", e);
                                break;
                        }
                        if((e = isbadcookie(&c, dom, path)) != nil){
                                if(cookiedebug)
                                        fprint(2, "reject cookie; %s\n", e);
                                continue;
                        }
                        addcookie(jar, &c);
                        n++;
                }
        }
        return n;
}

static char*
skipquoted(char *s)
{
        /*
         * Sec 2.2 of RFC2616 defines a "quoted-string" as:
         *
         *  quoted-string  = ( <"> *(qdtext | quoted-pair ) <"> )
         *  qdtext         = <any TEXT except <">>
         *  quoted-pair    = "\" CHAR
         *
         * TEXT is any octet except CTLs, but including LWS;
         * LWS is [CR LF] 1*(SP | HT);
         * CHARs are ASCII octets 0-127;  (NOTE: we reject 0's)
         * CTLs are octets 0-31 and 127;
         */
        if(*s != '"')
                return s;

        for(s++; 32 <= *s && *s < 127 && *s != '"'; s++)
                if(*s == '\\' && *(s+1) != '\0')
                        s++;
        return s;
}

static char*
skiptoken(char *s)
{
        /*
         * Sec 2.2 of RFC2616 defines a "token" as
         *  1*<any CHAR except CTLs or separators>;
         * CHARs are ASCII octets 0-127;
         * CTLs are octets 0-31 and 127;
         * separators are "()<>@,;:\/[]?={}", double-quote, SP (32), and HT (9)
         */
        while(32 <= *s && *s < 127 && strchr("()<>@,;:[]?={}\" \t\\", *s)==nil)
                s++;

        return s;
}

static char*
skipvalue(char *s, int isns)
{
        char *t;

        /*
         * An RFC2109 value is an HTTP token or an HTTP quoted string.
         * Netscape servers ignore the spec and rely on semicolons, apparently.
         */
        if(isns){
                if((t = strchr(s, ';')) == nil)
                        t = s+strlen(s);
                return t;
        }
        if(*s == '"')
                return skipquoted(s);
        return skiptoken(s);
}

/*
 * RMID=80b186bb64c03c65fab767f8; expires=Monday, 10-Feb-2003 04:44:39 GMT; 
 *      path=/; domain=.nytimes.com
 */
static char*
parsecookie(Cookie *c, char *p, char **e, int isns, char *dom, char *path)
{
        int i, done;
        char *t, *u, *attr, *val;

        c->expire = ~0;
        memset(c, 0, sizeof *c);

        /* NAME=VALUE */
        t = skiptoken(p);
        c->name = p;
        p = skipspace(t);
        if(*p != '='){
        Badname:
                return "malformed cookie: no NAME=VALUE";
        }
        *t = '\0';
        p = skipspace(p+1);
        t = skipvalue(p, isns);
        if(*t)
                *t++ = '\0';
        c->value = p;
        p = skipspace(t);
        if(c->name[0]=='\0' || c->value[0]=='\0')
                goto Badname;

        done = 0;
        for(; *p && !done; p=skipspace(p)){
                attr = p;
                t = skiptoken(p);
                u = skipspace(t);
                switch(*u){
                case '\0':
                        *t = '\0';
                        val = p = u;
                        break;
                case ';':
                        *t = '\0';
                        val = "";
                        p = u+1;
                        break;
                case '=':
                        *t = '\0';
                        val = skipspace(u+1);
                        p = skipvalue(val, isns);
                        if(*p==',')
                                done = 1;
                        if(*p)
                                *p++ = '\0';
                        break;
                case ',':
                        if(!isns){
                                val = "";
                                p = u;
                                *p++ = '\0';
                                done = 1;
                                break;
                        }
                default:
                        if(cookiedebug)
                                fprint(2, "syntax: %s\n", p);
                        return "syntax error";
                }
                for(i=0; i<nelem(stab); i++)
                        if(stab[i].ishttp && cistrcmp(stab[i].s, attr)==0)
                                *(char**)((uintptr)c+stab[i].offset) = val;
                if(cistrcmp(attr, "expires") == 0){
                        if(!isns)
                                return "non-netscape cookie has Expires tag";
                        if(!val[0])
                                return "bad expires tag";
                        c->expire = strtotime(val);
                        if(c->expire == ~0)
                                return "cannot parse netscape expires tag";
                }
                if(cistrcmp(attr, "max-age") == 0)
                        c->expire = time(0)+atoi(val);
                if(cistrcmp(attr, "secure") == 0)
                        c->secure = 1;
        }

        if(c->dom)
                c->explicitdom = 1;
        else
                c->dom = dom;
        if(c->path)
                c->explicitpath = 1;
        else{
                c->path = path;
                if((t = strchr(c->path, '?')) != 0)
                        *t = '\0';
                if((t = strrchr(c->path, '/')) != 0)
                        *t = '\0';
        }       
        c->netscapestyle = isns;
        *e = p;

        return nil;
}

Jar *jar;

typedef struct Aux Aux;
struct Aux
{
        char *dom;
        char *path;
        char *inhttp;
        char *outhttp;
        char *ctext;
        int rdoff;
};
enum
{
        AuxBuf = 4096,
        MaxCtext = 16*1024*1024,
};

void
cookieopen(Req *r)
{
        char *s, *es;
        int i, sz;
        Aux *a;

        syncjar(jar);
        a = emalloc9p(sizeof(Aux));
        r->fid->aux = a;
        if(r->ifcall.mode&OTRUNC){
                a->ctext = emalloc9p(1);
                a->ctext[0] = '\0';
        }else{
                sz = 256*jar->nc+1024;  /* BUG should do better */
                a->ctext = emalloc9p(sz);
                a->ctext[0] = '\0';
                s = a->ctext;
                es = s+sz;
                for(i=0; i<jar->nc; i++)
                        s = seprint(s, es, "%K\n", &jar->c[i]);
        }
        respond(r, nil);
}

void
cookieread(Req *r)
{
        Aux *a;

        a = r->fid->aux;
        readstr(r, a->ctext);
        respond(r, nil);
}

void
cookiewrite(Req *r)
{
        Aux *a;
        int sz;

        a = r->fid->aux;
        sz = r->ifcall.count+r->ifcall.offset;
        if(sz > strlen(a->ctext)){
                if(sz >= MaxCtext){
                        respond(r, "cookie file too large");
                        return;
                }
                a->ctext = erealloc9p(a->ctext, sz+1);
                a->ctext[sz] = '\0';
        }
        memmove(a->ctext+r->ifcall.offset, r->ifcall.data, r->ifcall.count);
        r->ofcall.count = r->ifcall.count;
        respond(r, nil);
}

void
cookieclunk(Fid *fid)
{
        char *p, *nextp;
        Aux *a;
        int i;

        a = fid->aux;
        if(a == nil)
                return;
        for(i=0; i<jar->nc; i++)
                jar->c[i].mark = 1;
        for(p=a->ctext; *p; p=nextp){
                if((nextp = strchr(p, '\n')) != nil)
                        *nextp++ = '\0';
                else
                        nextp = "";
                addtojar(jar, p, 0);
        }
        for(i=0; i<jar->nc; i++)
                if(jar->c[i].mark)
                        delcookie(jar, &jar->c[i]);
        syncjar(jar);
        free(a->dom);
        free(a->path);
        free(a->inhttp);
        free(a->outhttp);
        free(a->ctext);
        free(a);
}

void
closecookies(void)
{
        closejar(jar);
}

void
initcookies(char *file)
{
        char *home;

        fmtinstall('J', jarfmt);
        fmtinstall('K', cookiefmt);

        if(file == nil){
                home = getenv("home");
                if(home == nil)
                        sysfatal("no cookie file specified and no $home");
                file = emalloc9p(strlen(home)+30);
                strcpy(file, home);
                strcat(file, "/lib/webcookies");
        }
        jar = readjar(file);
        if(jar == nil)
                sysfatal("readjar: %r");
}

void
httpsetcookie(char *hdr, char *dom, char *path)
{
        if(path == nil)
                path = "/";

        parsehttp(jar, hdr, dom, path);
        syncjar(jar);
}

char*
httpcookies(char *dom, char *path, int issecure)
{
        char buf[1024];
        Jar *j;

        syncjar(jar);
        j = cookiesearch(jar, dom, path, issecure);
        snprint(buf, sizeof buf, "%J", j);
        closejar(j);
        return estrdup(buf);
}