ref: 518fd3ec8350a010e5ed6490e1106c66af8f4d02
dir: /sys/src/cmd/ip/imap4d/msg.c/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <libsec.h>
#include <auth.h>
#include <fcall.h>
#include "imap4d.h"
static void body64(int in, int out);
static void bodystrip(int in, int out);
static void cleanupHeader(Header *h);
static char *domBang(char *s);
static void freeMAddr(MAddr *a);
static void freeMimeHdr(MimeHdr *mh);
static char *headAddrSpec(char *e, char *w);
static MAddr *headAddresses(void);
static MAddr *headAddress(void);
static char *headAtom(char *disallowed);
static int headChar(int eat);
static char *headDomain(char *e);
static MAddr *headMAddr(MAddr *old);
static char *headPhrase(char *e, char *w);
static char *headQuoted(int start, int stop);
static char *headSkipWhite(int);
static void headSkip(void);
static char *headSubDomain(void);
static char *headText(void);
static void headToEnd(void);
static char *headWord(void);
static void mimeDescription(Header *h);
static void mimeDisposition(Header *h);
static void mimeEncoding(Header *h);
static void mimeId(Header *h);
static void mimeLanguage(Header *h);
static void mimeMd5(Header *h);
static MimeHdr *mimeParams(void);
static void mimeType(Header *h);
static MimeHdr *mkMimeHdr(char *s, char *t, MimeHdr *next);
static void msgAddDate(Msg *m);
static void msgAddHead(Msg *m, char *head, char *body);
static int msgBodySize(Msg *m);
static int msgHeader(Msg *m, Header *h, char *file);
static long msgReadFile(Msg *m, char *file, char **ss);
static int msgUnix(Msg *m, int top);
static void stripQuotes(char *q);
static MAddr *unixFrom(char *s);
static char bogusBody[] =
"This message contains null characters, so it cannot be displayed correctly.\r\n"
"Most likely you were sent a bogus message or a binary file.\r\n"
"\r\n"
"Each of the following attachments has a different version of the message.\r\n"
"The first is inlined with all non-printable characters stripped.\r\n"
"The second contains the message as it was stored in your mailbox.\r\n"
"The third has the initial header stripped.\r\n";
static char bogusMimeText[] =
"Content-Disposition: inline\r\n"
"Content-Type: text/plain; charset=\"US-ASCII\"\r\n"
"Content-Transfer-Encoding: 7bit\r\n";
static char bogusMimeBinary[] =
"Content-Disposition: attachment\r\n"
"Content-Type: application/octet-stream\r\n"
"Content-Transfer-Encoding: base64\r\n";
/*
* stop list for header fields
*/
static char *headFieldStop = ":";
static char *mimeTokenStop = "()<>@,;:\\\"/[]?=";
static char *headAtomStop = "()<>@,;:\\\".[]";
static uchar *headStr;
static uchar *lastWhite;
long
selectFields(char *dst, long n, char *hdr, SList *fields, int matches)
{
SList *f;
uchar *start;
char *s;
long m, nf;
headStr = (uchar*)hdr;
m = 0;
for(;;){
start = headStr;
s = headAtom(headFieldStop);
if(s == nil)
break;
headSkip();
for(f = fields; f != nil; f = f->next){
if(cistrcmp(s, f->s) == !matches){
nf = headStr - start;
if(m + nf > n)
return 0;
memmove(&dst[m], start, nf);
m += nf;
}
}
free(s);
}
if(m + 3 > n)
return 0;
dst[m++] = '\r';
dst[m++] = '\n';
dst[m] = '\0';
return m;
}
void
freeMsg(Msg *m)
{
Msg *k, *last;
free(m->iBuf);
freeMAddr(m->to);
if(m->replyTo != m->from)
freeMAddr(m->replyTo);
if(m->sender != m->from)
freeMAddr(m->sender);
if(m->from != m->unixFrom)
freeMAddr(m->from);
freeMAddr(m->unixFrom);
freeMAddr(m->cc);
freeMAddr(m->bcc);
free(m->unixDate);
cleanupHeader(&m->head);
cleanupHeader(&m->mime);
for(k = m->kids; k != nil; ){
last = k;
k = k->next;
freeMsg(last);
}
free(m->fs);
free(m);
}
ulong
msgSize(Msg *m)
{
return m->head.size + m->size;
}
int
infoIsNil(char *s)
{
return s == nil || s[0] == '\0';
}
char*
maddrStr(MAddr *a)
{
char *host, *addr;
int n;
host = a->host;
if(host == nil)
host = "";
n = strlen(a->box) + strlen(host) + 2;
if(a->personal != nil)
n += strlen(a->personal) + 3;
addr = emalloc(n);
if(a->personal != nil)
snprint(addr, n, "%s <%s@%s>", a->personal, a->box, host);
else
snprint(addr, n, "%s@%s", a->box, host);
return addr;
}
/*
* return actual name of f in m's fs directory
* this is special cased when opening m/rawbody, m/mimeheader, or m/rawheader,
* if the message was corrupted. in that case,
* a temporary file is made to hold the base64 encoding of m/raw.
*/
int
msgFile(Msg *m, char *f)
{
Msg *parent, *p;
Dir d;
Tm tm;
char buf[64], nbuf[2];
uchar dbuf[64];
int i, n, fd, fd1, fd2;
if(!m->bogus
|| strcmp(f, "") != 0 && strcmp(f, "rawbody") != 0
&& strcmp(f, "rawheader") != 0 && strcmp(f, "mimeheader") != 0
&& strcmp(f, "info") != 0 && strcmp(f, "unixheader") != 0){
if(strlen(f) > MsgNameLen)
bye("internal error: msgFile name too long");
strcpy(m->efs, f);
return cdOpen(m->fsDir, m->fs, OREAD);
}
/*
* walk up the stupid runt message parts for non-multipart messages
*/
parent = m->parent;
if(parent != nil && parent->parent != nil){
m = parent;
parent = m->parent;
}
p = m;
if(parent != nil)
p = parent;
if(strcmp(f, "info") == 0 || strcmp(f, "unixheader") == 0){
strcpy(p->efs, f);
return cdOpen(p->fsDir, p->fs, OREAD);
}
fd = imapTmp();
if(fd < 0)
return -1;
/*
* craft the message parts for bogus messages
*/
if(strcmp(f, "") == 0){
/*
* make a fake directory for each kid
* all we care about is the name
*/
if(parent == nil){
nulldir(&d);
d.mode = DMDIR|0600;
d.qid.type = QTDIR;
d.name = nbuf;
nbuf[1] = '\0';
for(i = '1'; i <= '4'; i++){
nbuf[0] = i;
n = convD2M(&d, dbuf, sizeof(dbuf));
if(n <= BIT16SZ)
fprint(2, "bad convD2M %d\n", n);
write(fd, dbuf, n);
}
}
}else if(strcmp(f, "mimeheader") == 0){
if(parent != nil){
switch(m->id){
case 1:
case 2:
fprint(fd, "%s", bogusMimeText);
break;
case 3:
case 4:
fprint(fd, "%s", bogusMimeBinary);
break;
}
}
}else if(strcmp(f, "rawheader") == 0){
if(parent == nil){
date2tm(&tm, m->unixDate);
rfc822date(buf, sizeof(buf), &tm);
fprint(fd,
"Date: %s\r\n"
"From: imap4 daemon <%s@%s>\r\n"
"To: <%s@%s>\r\n"
"Subject: This message was illegal or corrupted\r\n"
"MIME-Version: 1.0\r\n"
"Content-Type: multipart/mixed;\r\n\tboundary=\"upas-%s\"\r\n",
buf, username, site, username, site, m->info[IDigest]);
}
}else if(strcmp(f, "rawbody") == 0){
fd1 = msgFile(p, "raw");
strcpy(p->efs, "rawbody");
fd2 = cdOpen(p->fsDir, p->fs, OREAD);
if(fd1 < 0 || fd2 < 0){
close(fd);
close(fd1);
close(fd2);
return -1;
}
if(parent == nil){
fprint(fd,
"This is a multi-part message in MIME format.\r\n"
"--upas-%s\r\n"
"%s"
"\r\n"
"%s"
"\r\n",
m->info[IDigest], bogusMimeText, bogusBody);
fprint(fd,
"--upas-%s\r\n"
"%s"
"\r\n",
m->info[IDigest], bogusMimeText);
bodystrip(fd1, fd);
fprint(fd,
"--upas-%s\r\n"
"%s"
"\r\n",
m->info[IDigest], bogusMimeBinary);
seek(fd1, 0, 0);
body64(fd1, fd);
fprint(fd,
"--upas-%s\r\n"
"%s"
"\r\n",
m->info[IDigest], bogusMimeBinary);
body64(fd2, fd);
fprint(fd, "--upas-%s--\r\n", m->info[IDigest]);
}else{
switch(m->id){
case 1:
fprint(fd, "%s", bogusBody);
break;
case 2:
bodystrip(fd1, fd);
break;
case 3:
body64(fd1, fd);
break;
case 4:
body64(fd2, fd);
break;
}
}
close(fd1);
close(fd2);
}
seek(fd, 0, 0);
return fd;
}
int
msgIsMulti(Header *h)
{
return h->type != nil && cistrcmp("multipart", h->type->s) == 0;
}
int
msgIsRfc822(Header *h)
{
return h->type != nil && cistrcmp("message", h->type->s) == 0 && cistrcmp("rfc822", h->type->t) == 0;
}
/*
* check if a message has been deleted by someone else
*/
void
msgDead(Msg *m)
{
if(m->expunged)
return;
*m->efs = '\0';
if(!cdExists(m->fsDir, m->fs))
m->expunged = 1;
}
/*
* make sure the message has valid associated info
* used for ISubject, IDigest, IInReplyTo, IMessageId.
*/
int
msgInfo(Msg *m)
{
char *s;
int i;
if(m->info[0] != nil)
return 1;
i = msgReadFile(m, "info", &m->iBuf);
if(i < 0)
return 0;
s = m->iBuf;
for(i = 0; i < IMax; i++){
m->info[i] = s;
s = strchr(s, '\n');
if(s == nil)
break;
*s++ = '\0';
}
for(; i < IMax; i++)
m->info[i] = nil;
for(i = 0; i < IMax; i++)
if(infoIsNil(m->info[i]))
m->info[i] = nil;
return 1;
}
/*
* make sure the message has valid mime structure
* and sub-messages
*/
int
msgStruct(Msg *m, int top)
{
Msg *k, head, *last;
Dir *d;
char *s;
ulong max, id;
int i, nd, fd, ns;
if(m->kids != nil)
return 1;
if(m->expunged
|| !msgInfo(m)
|| !msgUnix(m, top)
|| !msgBodySize(m)
|| !msgHeader(m, &m->mime, "mimeheader")
|| (top || msgIsRfc822(&m->mime) || msgIsMulti(&m->mime)) && !msgHeader(m, &m->head, "rawheader")){
if(top && m->bogus && !(m->bogus & BogusTried)){
m->bogus |= BogusTried;
return msgStruct(m, top);
}
msgDead(m);
return 0;
}
/*
* if a message has no kids, it has a kid which is just the body of the real message
*/
if(!msgIsMulti(&m->head) && !msgIsMulti(&m->mime) && !msgIsRfc822(&m->head) && !msgIsRfc822(&m->mime)){
k = MKZ(Msg);
k->id = 1;
k->fsDir = m->fsDir;
k->bogus = m->bogus;
k->parent = m->parent;
ns = m->efs - m->fs;
k->fs = emalloc(ns + (MsgNameLen + 1));
memmove(k->fs, m->fs, ns);
k->efs = k->fs + ns;
*k->efs = '\0';
k->size = m->size;
m->kids = k;
return 1;
}
/*
* read in all child messages messages
*/
fd = msgFile(m, "");
if(fd < 0){
msgDead(m);
return 0;
}
max = 0;
head.next = nil;
last = &head;
while((nd = dirread(fd, &d)) > 0){
for(i = 0; i < nd; i++){
s = d[i].name;
id = strtol(s, &s, 10);
if(id <= max || *s != '\0'
|| (d[i].mode & DMDIR) != DMDIR)
continue;
max = id;
k = MKZ(Msg);
k->id = id;
k->fsDir = m->fsDir;
k->bogus = m->bogus;
k->parent = m;
ns = strlen(m->fs);
k->fs = emalloc(ns + 2 * (MsgNameLen + 1));
k->efs = seprint(k->fs, k->fs + ns + (MsgNameLen + 1), "%s%lud/", m->fs, id);
k->prev = last;
k->size = ~0UL;
k->lines = ~0UL;
last->next = k;
last = k;
}
}
close(fd);
m->kids = head.next;
/*
* if kids fail, just whack them
*/
top = top && (msgIsRfc822(&m->head) || msgIsMulti(&m->head));
for(k = m->kids; k != nil; k = k->next){
if(!msgStruct(k, top)){
for(k = m->kids; k != nil; ){
last = k;
k = k->next;
freeMsg(last);
}
m->kids = nil;
break;
}
}
return 1;
}
static long
msgReadFile(Msg *m, char *file, char **ss)
{
Dir *d;
char *s, buf[BufSize];
vlong length;
long n, nn;
int fd;
fd = msgFile(m, file);
if(fd < 0){
msgDead(m);
return -1;
}
n = read(fd, buf, BufSize);
if(n < BufSize){
close(fd);
if(n < 0){
*ss = nil;
return -1;
}
s = emalloc(n + 1);
memmove(s, buf, n);
s[n] = '\0';
*ss = s;
return n;
}
d = dirfstat(fd);
if(d == nil){
close(fd);
return -1;
}
length = d->length;
free(d);
nn = length;
s = emalloc(nn + 1);
memmove(s, buf, n);
if(nn > n)
nn = readn(fd, s+n, nn-n) + n;
close(fd);
if(nn != length){
free(s);
return -1;
}
s[nn] = '\0';
*ss = s;
return nn;
}
static void
freeMAddr(MAddr *a)
{
MAddr *p;
while(a != nil){
p = a;
a = a->next;
free(p->personal);
free(p->box);
free(p->host);
free(p);
}
}
/*
* the message is corrupted or illegal.
* reset message fields. msgStruct will reparse the message,
* relying on msgFile to make up corrected body parts.
*/
static int
msgBogus(Msg *m, int flags)
{
if(!(m->bogus & flags))
m->bogus |= flags;
m->lines = ~0;
free(m->head.buf);
free(m->mime.buf);
memset(&m->head, 0, sizeof(Header));
memset(&m->mime, 0, sizeof(Header));
return 0;
}
/*
* stolen from upas/marshal; base64 encodes from one fd to another.
*
* the size of buf is very important to enc64. Anything other than
* a multiple of 3 will cause enc64 to output a termination sequence.
* To ensure that a full buf corresponds to a multiple of complete lines,
* we make buf a multiple of 3*18 since that's how many enc64 sticks on
* a single line. This avoids short lines in the output which is pleasing
* but not necessary.
*/
static int
enc64x18(char *out, int lim, uchar *in, int n)
{
int m, mm, nn;
for(nn = 0; n > 0; n -= m, nn += mm){
m = 18 * 3;
if(m > n)
m = n;
nn += 2; /* \r\n */
assert(nn < lim);
mm = enc64(out, lim - nn, in, m);
assert(mm > 0);
in += m;
out += mm;
*out++ = '\r';
*out++ = '\n';
}
return nn;
}
static void
body64(int in, int out)
{
uchar buf[3*18*54];
char obuf[3*18*54*2];
int m, n;
for(;;){
n = readn(in, buf, sizeof(buf));
if(n < 0)
return;
if(n == 0)
break;
m = enc64x18(obuf, sizeof(obuf), buf, n);
if(write(out, obuf, m) < 0)
return;
}
}
/*
* strip all non-printable characters from a file
*/
static void
bodystrip(int in, int out)
{
uchar buf[3*18*54];
int m, n, i, c;
for(;;){
n = read(in, buf, sizeof(buf));
if(n < 0)
return;
if(n == 0)
break;
m = 0;
for(i = 0; i < n; i++){
c = buf[i];
if(c > 0x1f && c < 0x7f /* normal characters */
|| c >= 0x9 && c <= 0xd) /* \t, \n, vertical tab, form feed, \r */
buf[m++] = c;
}
if(m && write(out, buf, m) < 0)
return;
}
}
/*
* read in the message body to count \n without a preceding \r
*/
static int
msgBodySize(Msg *m)
{
Dir *d;
char buf[BufSize + 2], *s, *se;
vlong length;
ulong size, lines, bad;
int n, fd, c;
if(m->lines != ~0UL)
return 1;
fd = msgFile(m, "rawbody");
if(fd < 0)
return 0;
d = dirfstat(fd);
if(d == nil){
close(fd);
return 0;
}
length = d->length;
free(d);
size = 0;
lines = 0;
bad = 0;
buf[0] = ' ';
for(;;){
n = read(fd, &buf[1], BufSize);
if(n <= 0)
break;
size += n;
se = &buf[n + 1];
for(s = &buf[1]; s < se; s++){
c = *s;
if(c == '\0'){
close(fd);
return msgBogus(m, BogusBody);
}
if(c != '\n')
continue;
if(s[-1] != '\r')
bad++;
lines++;
}
buf[0] = buf[n];
}
if(size != length)
bye("bad length reading rawbody");
size += bad;
m->size = size;
m->lines = lines;
close(fd);
return 1;
}
/*
* retrieve information from the unixheader file
*/
static int
msgUnix(Msg *m, int top)
{
Tm tm;
char *s, *ss;
if(m->unixDate != nil)
return 1;
if(!top){
bogus:
m->unixDate = estrdup("");
m->unixFrom = unixFrom(nil);
return 1;
}
if(msgReadFile(m, "unixheader", &ss) < 0)
return 0;
s = ss;
s = strchr(s, ' ');
if(s == nil){
free(ss);
goto bogus;
}
s++;
m->unixFrom = unixFrom(s);
s = (char*)headStr;
if(date2tm(&tm, s) == nil)
s = m->info[IUnixDate];
if(s == nil){
free(ss);
goto bogus;
}
m->unixDate = estrdup(s);
free(ss);
return 1;
}
/*
* parse the address in the unix header
* last line of defence, so must return something
*/
static MAddr *
unixFrom(char *s)
{
MAddr *a;
char *e, *t;
if(s == nil)
return nil;
headStr = (uchar*)s;
t = emalloc(strlen(s) + 2);
e = headAddrSpec(t, nil);
if(e == nil)
a = nil;
else{
if(*e != '\0')
*e++ = '\0';
else
e = site;
a = MKZ(MAddr);
a->box = estrdup(t);
a->host = estrdup(e);
}
free(t);
return a;
}
/*
* read in the entire header,
* and parse out any existing mime headers
*/
static int
msgHeader(Msg *m, Header *h, char *file)
{
char *s, *ss, *t, *te;
ulong lines, n, nn;
long ns;
int dated, c;
if(h->buf != nil)
return 1;
ns = msgReadFile(m, file, &ss);
if(ns < 0)
return 0;
s = ss;
n = ns;
/*
* count lines ending with \n and \r\n
* add an extra line at the end, since upas/fs headers
* don't have a terminating \r\n
*/
lines = 1;
te = s + ns;
for(t = s; t < te; t++){
c = *t;
if(c == '\0')
return msgBogus(m, BogusHeader);
if(c != '\n')
continue;
if(t == s || t[-1] != '\r')
n++;
lines++;
}
if(t > s && t[-1] != '\n'){
if(t[-1] != '\r')
n++;
n++;
}
n += 2;
h->buf = emalloc(n + 1);
h->size = n;
h->lines = lines;
/*
* make sure all headers end in \r\n
*/
nn = 0;
for(t = s; t < te; t++){
c = *t;
if(c == '\n'){
if(!nn || h->buf[nn - 1] != '\r')
h->buf[nn++] = '\r';
lines++;
}
h->buf[nn++] = c;
}
if(nn && h->buf[nn-1] != '\n'){
if(h->buf[nn-1] != '\r')
h->buf[nn++] = '\r';
h->buf[nn++] = '\n';
}
h->buf[nn++] = '\r';
h->buf[nn++] = '\n';
h->buf[nn] = '\0';
if(nn != n)
bye("misconverted header %ld %ld", nn, n);
free(s);
/*
* and parse some mime headers
*/
headStr = (uchar*)h->buf;
dated = 0;
while(s = headAtom(headFieldStop)){
if(cistrcmp(s, "content-type") == 0)
mimeType(h);
else if(cistrcmp(s, "content-transfer-encoding") == 0)
mimeEncoding(h);
else if(cistrcmp(s, "content-id") == 0)
mimeId(h);
else if(cistrcmp(s, "content-description") == 0)
mimeDescription(h);
else if(cistrcmp(s, "content-disposition") == 0)
mimeDisposition(h);
else if(cistrcmp(s, "content-md5") == 0)
mimeMd5(h);
else if(cistrcmp(s, "content-language") == 0)
mimeLanguage(h);
else if(h == &m->head && cistrcmp(s, "from") == 0)
m->from = headMAddr(m->from);
else if(h == &m->head && cistrcmp(s, "to") == 0)
m->to = headMAddr(m->to);
else if(h == &m->head && cistrcmp(s, "reply-to") == 0)
m->replyTo = headMAddr(m->replyTo);
else if(h == &m->head && cistrcmp(s, "sender") == 0)
m->sender = headMAddr(m->sender);
else if(h == &m->head && cistrcmp(s, "cc") == 0)
m->cc = headMAddr(m->cc);
else if(h == &m->head && cistrcmp(s, "bcc") == 0)
m->bcc = headMAddr(m->bcc);
else if(h == &m->head && cistrcmp(s, "date") == 0)
dated = 1;
headSkip();
free(s);
}
if(h == &m->head){
if(m->from == nil){
m->from = m->unixFrom;
if(m->from != nil){
s = maddrStr(m->from);
msgAddHead(m, "From", s);
free(s);
}
}
if(m->sender == nil)
m->sender = m->from;
if(m->replyTo == nil)
m->replyTo = m->from;
if(infoIsNil(m->info[IDate]))
m->info[IDate] = m->unixDate;
if(!dated && m->from != nil)
msgAddDate(m);
}
return 1;
}
/*
* prepend head: body to the cached header
*/
static void
msgAddHead(Msg *m, char *head, char *body)
{
char *s;
long size, n;
n = strlen(head) + strlen(body) + 4;
size = m->head.size + n;
s = emalloc(size + 1);
snprint(s, size + 1, "%s: %s\r\n%s", head, body, m->head.buf);
free(m->head.buf);
m->head.buf = s;
m->head.size = size;
m->head.lines++;
}
static void
msgAddDate(Msg *m)
{
Tm tm;
char buf[64];
/* don't bother if we don't have a date */
if(infoIsNil(m->info[IDate]))
return;
date2tm(&tm, m->info[IDate]);
rfc822date(buf, sizeof(buf), &tm);
msgAddHead(m, "Date", buf);
}
static MimeHdr*
mkMimeHdr(char *s, char *t, MimeHdr *next)
{
MimeHdr *mh;
mh = MK(MimeHdr);
mh->s = s;
mh->t = t;
mh->next = next;
return mh;
}
static void
freeMimeHdr(MimeHdr *mh)
{
MimeHdr *last;
while(mh != nil){
last = mh;
mh = mh->next;
free(last->s);
free(last->t);
free(last);
}
}
static void
cleanupHeader(Header *h)
{
freeMimeHdr(h->type);
freeMimeHdr(h->id);
freeMimeHdr(h->description);
freeMimeHdr(h->encoding);
freeMimeHdr(h->md5);
freeMimeHdr(h->disposition);
freeMimeHdr(h->language);
}
/*
* parser for rfc822 & mime header fields
*/
/*
* type : 'content-type' ':' token '/' token params
*/
static void
mimeType(Header *h)
{
char *s, *t;
if(headChar(1) != ':')
return;
s = headAtom(mimeTokenStop);
if(s == nil || headChar(1) != '/'){
free(s);
return;
}
t = headAtom(mimeTokenStop);
if(t == nil){
free(s);
return;
}
h->type = mkMimeHdr(s, t, mimeParams());
}
/*
* params :
* | params ';' token '=' token
* | params ';' token '=' quoted-str
*/
static MimeHdr*
mimeParams(void)
{
MimeHdr head, *last;
char *s, *t;
head.next = nil;
last = &head;
for(;;){
if(headChar(1) != ';')
break;
s = headAtom(mimeTokenStop);
if(s == nil || headChar(1) != '='){
free(s);
break;
}
if(headChar(0) == '"'){
t = headQuoted('"', '"');
stripQuotes(t);
}else
t = headAtom(mimeTokenStop);
if(t == nil){
free(s);
break;
}
last->next = mkMimeHdr(s, t, nil);
last = last->next;
}
return head.next;
}
/*
* encoding : 'content-transfer-encoding' ':' token
*/
static void
mimeEncoding(Header *h)
{
char *s;
if(headChar(1) != ':')
return;
s = headAtom(mimeTokenStop);
if(s == nil)
return;
h->encoding = mkMimeHdr(s, nil, nil);
}
/*
* mailaddr : ':' addresses
*/
static MAddr*
headMAddr(MAddr *old)
{
MAddr *a;
if(headChar(1) != ':')
return old;
if(headChar(0) == '\n')
return old;
a = headAddresses();
if(a == nil)
return old;
freeMAddr(old);
return a;
}
/*
* addresses : address | addresses ',' address
*/
static MAddr*
headAddresses(void)
{
MAddr *addr, *tail, *a;
addr = headAddress();
if(addr == nil)
return nil;
tail = addr;
while(headChar(0) == ','){
headChar(1);
a = headAddress();
if(a == nil){
freeMAddr(addr);
return nil;
}
tail->next = a;
tail = a;
}
return addr;
}
/*
* address : mailbox | group
* group : phrase ':' mboxes ';' | phrase ':' ';'
* mailbox : addr-spec
* | optphrase '<' addr-spec '>'
* | optphrase '<' route ':' addr-spec '>'
* optphrase : | phrase
* route : '@' domain
* | route ',' '@' domain
* personal names are the phrase before '<',
* or a comment before or after a simple addr-spec
*/
static MAddr*
headAddress(void)
{
MAddr *addr;
uchar *hs;
char *s, *e, *w, *personal;
int c;
s = emalloc(strlen((char*)headStr) + 2);
e = s;
personal = headSkipWhite(1);
c = headChar(0);
if(c == '<')
w = nil;
else{
w = headWord();
c = headChar(0);
}
if(c == '.' || c == '@' || c == ',' || c == '\n' || c == '\0'){
lastWhite = headStr;
e = headAddrSpec(s, w);
if(personal == nil){
hs = headStr;
headStr = lastWhite;
personal = headSkipWhite(1);
headStr = hs;
}
}else{
if(c != '<' || w != nil){
free(personal);
if(!headPhrase(e, w)){
free(s);
return nil;
}
/*
* ignore addresses with groups,
* so the only thing left if <
*/
c = headChar(1);
if(c != '<'){
free(s);
return nil;
}
personal = estrdup(s);
}else
headChar(1);
/*
* after this point, we need to free personal before returning.
* set e to nil to everything afterwards fails.
*
* ignore routes, they are useless, and heavily discouraged in rfc1123.
* imap4 reports them up to, but not including, the terminating :
*/
e = s;
c = headChar(0);
if(c == '@'){
for(;;){
c = headChar(1);
if(c != '@'){
e = nil;
break;
}
headDomain(e);
c = headChar(1);
if(c != ','){
e = s;
break;
}
}
if(c != ':')
e = nil;
}
if(e != nil)
e = headAddrSpec(s, nil);
if(headChar(1) != '>')
e = nil;
}
/*
* e points to @host, or nil if an error occured
*/
if(e == nil){
free(personal);
addr = nil;
}else{
if(*e != '\0')
*e++ = '\0';
else
e = site;
addr = MKZ(MAddr);
addr->personal = personal;
addr->box = estrdup(s);
addr->host = estrdup(e);
}
free(s);
return addr;
}
/*
* phrase : word
* | phrase word
* w is the optional initial word of the phrase
* returns the end of the phrase, or nil if a failure occured
*/
static char*
headPhrase(char *e, char *w)
{
int c;
for(;;){
if(w == nil){
w = headWord();
if(w == nil)
return nil;
}
if(w[0] == '"')
stripQuotes(w);
strcpy(e, w);
free(w);
w = nil;
e = strchr(e, '\0');
c = headChar(0);
if(c <= ' ' || strchr(headAtomStop, c) != nil && c != '"')
break;
*e++ = ' ';
*e = '\0';
}
return e;
}
/*
* addr-spec : local-part '@' domain
* | local-part extension to allow ! and local names
* local-part : word
* | local-part '.' word
*
* if no '@' is present, rewrite d!e!f!u as @d,@e:u@f,
* where d, e, f are valid domain components.
* the @d,@e: is ignored, since routes are ignored.
* perhaps they should be rewritten as e!f!u@d, but that is inconsistent with upas.
*
* returns a pointer to '@', the end if none, or nil if there was an error
*/
static char*
headAddrSpec(char *e, char *w)
{
char *s, *at, *b, *bang, *dom;
int c;
s = e;
for(;;){
if(w == nil){
w = headWord();
if(w == nil)
return nil;
}
strcpy(e, w);
free(w);
w = nil;
e = strchr(e, '\0');
lastWhite = headStr;
c = headChar(0);
if(c != '.')
break;
headChar(1);
*e++ = '.';
*e = '\0';
}
if(c != '@'){
/*
* extenstion: allow name without domain
* check for domain!xxx
*/
bang = domBang(s);
if(bang == nil)
return e;
/*
* if dom1!dom2!xxx, ignore dom1!
*/
dom = s;
for(; b = domBang(bang + 1); bang = b)
dom = bang + 1;
/*
* convert dom!mbox into mbox@dom
*/
*bang = '@';
strrev(dom, bang);
strrev(bang+1, e);
strrev(dom, e);
bang = &dom[e - bang - 1];
if(dom > s){
bang -= dom - s;
for(e = s; *e = *dom; e++)
dom++;
}
/*
* eliminate a trailing '.'
*/
if(e[-1] == '.')
e[-1] = '\0';
return bang;
}
headChar(1);
at = e;
*e++ = '@';
*e = '\0';
if(!headDomain(e))
return nil;
return at;
}
/*
* find the ! in domain!rest, where domain must have at least
* one internal '.'
*/
static char*
domBang(char *s)
{
int dot, c;
dot = 0;
for(; c = *s; s++){
if(c == '!'){
if(!dot || dot == 1 && s[-1] == '.' || s[1] == '\0')
return nil;
return s;
}
if(c == '"')
break;
if(c == '.')
dot++;
}
return nil;
}
/*
* domain : sub-domain
* | domain '.' sub-domain
* returns the end of the domain, or nil if a failure occured
*/
static char*
headDomain(char *e)
{
char *w;
for(;;){
w = headSubDomain();
if(w == nil)
return nil;
strcpy(e, w);
free(w);
e = strchr(e, '\0');
lastWhite = headStr;
if(headChar(0) != '.')
break;
headChar(1);
*e++ = '.';
*e = '\0';
}
return e;
}
/*
* id : 'content-id' ':' msg-id
* msg-id : '<' addr-spec '>'
*/
static void
mimeId(Header *h)
{
char *s, *e, *w;
if(headChar(1) != ':')
return;
if(headChar(1) != '<')
return;
s = emalloc(strlen((char*)headStr) + 3);
e = s;
*e++ = '<';
e = headAddrSpec(e, nil);
if(e == nil || headChar(1) != '>'){
free(s);
return;
}
e = strchr(e, '\0');
*e++ = '>';
e[0] = '\0';
w = strdup(s);
free(s);
h->id = mkMimeHdr(w, nil, nil);
}
/*
* description : 'content-description' ':' *text
*/
static void
mimeDescription(Header *h)
{
if(headChar(1) != ':')
return;
headSkipWhite(0);
h->description = mkMimeHdr(headText(), nil, nil);
}
/*
* disposition : 'content-disposition' ':' token params
*/
static void
mimeDisposition(Header *h)
{
char *s;
if(headChar(1) != ':')
return;
s = headAtom(mimeTokenStop);
if(s == nil)
return;
h->disposition = mkMimeHdr(s, nil, mimeParams());
}
/*
* md5 : 'content-md5' ':' token
*/
static void
mimeMd5(Header *h)
{
char *s;
if(headChar(1) != ':')
return;
s = headAtom(mimeTokenStop);
if(s == nil)
return;
h->md5 = mkMimeHdr(s, nil, nil);
}
/*
* language : 'content-language' ':' langs
* langs : token
* | langs commas token
* commas : ','
* | commas ','
*/
static void
mimeLanguage(Header *h)
{
MimeHdr head, *last;
char *s;
head.next = nil;
last = &head;
for(;;){
s = headAtom(mimeTokenStop);
if(s == nil)
break;
last->next = mkMimeHdr(s, nil, nil);
last = last->next;
while(headChar(0) != ',')
headChar(1);
}
h->language = head.next;
}
/*
* token : 1*<char 33-255, except "()<>@,;:\\\"/[]?=" aka mimeTokenStop>
* atom : 1*<chars 33-255, except "()<>@,;:\\\".[]" aka headAtomStop>
* note this allows 8 bit characters, which occur in utf.
*/
static char*
headAtom(char *disallowed)
{
char *s;
int c, ns, as;
headSkipWhite(0);
s = emalloc(StrAlloc);
as = StrAlloc;
ns = 0;
for(;;){
c = *headStr++;
if(c <= ' ' || strchr(disallowed, c) != nil){
headStr--;
break;
}
s[ns++] = c;
if(ns >= as){
as += StrAlloc;
s = erealloc(s, as);
}
}
if(ns == 0){
free(s);
return 0;
}
s[ns] = '\0';
return s;
}
/*
* sub-domain : atom | domain-lit
*/
static char *
headSubDomain(void)
{
if(headChar(0) == '[')
return headQuoted('[', ']');
return headAtom(headAtomStop);
}
/*
* word : atom | quoted-str
*/
static char *
headWord(void)
{
if(headChar(0) == '"')
return headQuoted('"', '"');
return headAtom(headAtomStop);
}
/*
* q is a quoted string. remove enclosing " and and \ escapes
*/
static void
stripQuotes(char *q)
{
char *s;
int c;
if(q == nil)
return;
s = q++;
while(c = *q++){
if(c == '\\'){
c = *q++;
if(!c)
return;
}
*s++ = c;
}
s[-1] = '\0';
}
/*
* quoted-str : '"' *(any char but '"\\\r', or '\' any char, or linear-white-space) '"'
* domain-lit : '[' *(any char but '[]\\\r', or '\' any char, or linear-white-space) ']'
*/
static char *
headQuoted(int start, int stop)
{
char *s;
int c, ns, as;
if(headChar(1) != start)
return nil;
s = emalloc(StrAlloc);
as = StrAlloc;
ns = 0;
s[ns++] = start;
for(;;){
c = *headStr;
if(c == stop){
headStr++;
break;
}
if(c == '\0'){
free(s);
return nil;
}
if(c == '\r'){
headStr++;
continue;
}
if(c == '\n'){
headStr++;
while(*headStr == ' ' || *headStr == '\t' || *headStr == '\r' || *headStr == '\n')
headStr++;
c = ' ';
}else if(c == '\\'){
headStr++;
s[ns++] = c;
c = *headStr;
if(c == '\0'){
free(s);
return nil;
}
headStr++;
}else
headStr++;
s[ns++] = c;
if(ns + 1 >= as){ /* leave room for \c or "0 */
as += StrAlloc;
s = erealloc(s, as);
}
}
s[ns++] = stop;
s[ns] = '\0';
return s;
}
/*
* headText : contents of rest of header line
*/
static char *
headText(void)
{
uchar *v;
char *s;
v = headStr;
headToEnd();
s = emalloc(headStr - v + 1);
memmove(s, v, headStr - v);
s[headStr - v] = '\0';
return s;
}
/*
* white space is ' ' '\t' or nested comments.
* skip white space.
* if com and a comment is seen,
* return it's contents and stop processing white space.
*/
static char*
headSkipWhite(int com)
{
char *s;
int c, incom, as, ns;
s = nil;
as = StrAlloc;
ns = 0;
if(com)
s = emalloc(StrAlloc);
incom = 0;
for(; c = *headStr; headStr++){
switch(c){
case ' ':
case '\t':
case '\r':
c = ' ';
break;
case '\n':
c = headStr[1];
if(c != ' ' && c != '\t')
goto breakout;
c = ' ';
break;
case '\\':
if(com && incom)
s[ns++] = c;
c = headStr[1];
if(c == '\0')
goto breakout;
headStr++;
break;
case '(':
incom++;
if(incom == 1)
continue;
break;
case ')':
incom--;
if(com && !incom){
s[ns] = '\0';
return s;
}
break;
default:
if(!incom)
goto breakout;
break;
}
if(com && incom && (c != ' ' || ns > 0 && s[ns-1] != ' ')){
s[ns++] = c;
if(ns + 1 >= as){ /* leave room for \c or 0 */
as += StrAlloc;
s = erealloc(s, as);
}
}
}
breakout:;
free(s);
return nil;
}
/*
* return the next non-white character
*/
static int
headChar(int eat)
{
int c;
headSkipWhite(0);
c = *headStr;
if(eat && c != '\0' && c != '\n')
headStr++;
return c;
}
static void
headToEnd(void)
{
uchar *s;
int c;
for(;;){
s = headStr;
c = *s++;
while(c == '\r')
c = *s++;
if(c == '\n'){
c = *s++;
if(c != ' ' && c != '\t')
return;
}
if(c == '\0')
return;
headStr = s;
}
}
static void
headSkip(void)
{
int c;
while(c = *headStr){
headStr++;
if(c == '\n'){
c = *headStr;
if(c == ' ' || c == '\t')
continue;
return;
}
}
}