/* spool.c -- Routines for spooling/parsing messages from a prot stream
*
* Copyright (c) 1994-2008 Carnegie Mellon University. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The name "Carnegie Mellon University" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For permission or any legal
* details, please contact
* Carnegie Mellon University
* Center for Technology Transfer and Enterprise Creation
* 4615 Forbes Avenue
* Suite 302
* Pittsburgh, PA 15213
* (412) 268-7393, fax: (412) 268-7395
* innovation@andrew.cmu.edu
*
* 4. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Computing Services
* at Carnegie Mellon University (http://www.cmu.edu/computing/)."
*
* CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <config.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <stdio.h>
#include <string.h>
#include "assert.h"
#include "spool.h"
#include "util.h"
#include "xmalloc.h"
#include "global.h"
#include "strarray.h"
/* generated headers are not necessarily in current directory */
#include "imap/imap_err.h"
hdrcache_t spool_new_hdrcache(void)
{
hash_table *ht = xmalloc(sizeof(*ht));
return construct_hash_table(ht, 4000, 0);
}
/* take a list of headers, pull the first one out and return it in
name and contents.
copies fin to fout, massaging
returns 0 on success, negative on failure */
typedef enum {
NAME_START,
NAME,
COLON,
BODY_START,
BODY
} state;
/* we don't have to worry about dotstuffing here, since it's illegal
for a header to begin with a dot!
returns 0 on success, filling in 'headname' and 'contents' with a static
pointer (blech).
on end of headers, returns 0 with NULL 'headname' and NULL 'contents'
on error, returns < 0
*/
static int parseheader(struct protstream *fin, FILE *fout,
char **headname, char **contents,
const char **skipheaders)
{
int c;
static struct buf name = BUF_INITIALIZER;
static struct buf body = BUF_INITIALIZER;
state s = NAME_START;
int r = 0;
int reject8bit = config_getswitch(IMAPOPT_REJECT8BIT);
int munge8bit = config_getswitch(IMAPOPT_MUNGE8BIT);
const char **skip = NULL;
buf_reset(&name);
buf_reset(&body);
/* there are two ways out of this loop, both via gotos:
either we successfully read a header (got_header)
or we hit an error (ph_error) */
while ((c = prot_getc(fin)) != EOF) { /* examine each character */
/* reject \0 */
if (!c) {
r = IMAP_MESSAGE_CONTAINSNULL;
goto ph_error;
}
switch (s) {
case NAME_START:
if (c == '.') {
int peek;
peek = prot_getc(fin);
prot_ungetc(peek, fin);
if (peek == '\r' || peek == '\n') {
/* just reached the end of message */
r = 0;
goto ph_error;
}
}
if (c == '\r' || c == '\n') {
/* just reached the end of headers */
r = 0;
goto ph_error;
}
/* field-name = 1*ftext
ftext = %d33-57 / %d59-126
; Any character except
; controls, SP, and
; ":". */
if (!((c >= 33 && c <= 57) || (c >= 59 && c <= 126))) {
/* invalid header name */
r = IMAP_MESSAGE_BADHEADER;
goto ph_error;
}
buf_putc(&name, c);
s = NAME;
break;
case NAME:
if (c == ' ' || c == '\t' || c == ':') {
buf_cstring(&name);
/* see if this header is in our skip list */
for (skip = skipheaders;
skip && *skip && strcasecmp(name.s, *skip); skip++);
if (!skip || !*skip) {
/* write the header name to the output */
if (fout) fputs(name.s, fout);
skip = NULL;
}
s = (c == ':' ? BODY_START : COLON);
break;
}
if (!((c >= 33 && c <= 57) || (c >= 59 && c <= 126))) {
r = IMAP_MESSAGE_BADHEADER;
goto ph_error;
}
buf_putc(&name, c);
break;
case COLON:
if (c == ':') {
s = BODY_START;
} else if (c != ' ' && c != '\t') {
/* i want to avoid confusing dot-stuffing later */
while (c == '.') {
if (fout && !skip) fputc(c, fout);
c = prot_getc(fin);
}
r = IMAP_MESSAGE_BADHEADER;
goto ph_error;
}
break;
case BODY_START:
if (c == ' ' || c == '\t') /* eat the whitespace */
break;
buf_reset(&body);
s = BODY;
/* falls through! */
case BODY:
/* now we want to convert all newlines into \r\n */
if (c == '\r' || c == '\n') {
int peek;
peek = prot_getc(fin);
if (fout && !skip) {
fputc('\r', fout);
fputc('\n', fout);
}
/* we should peek ahead to see if it's folded whitespace */
if (c == '\r' && peek == '\n') {
c = prot_getc(fin);
} else {
c = peek; /* single newline seperator */
}
if (c != ' ' && c != '\t') {
/* this is the end of the header */
buf_cstring(&body);
prot_ungetc(c, fin);
goto got_header;
}
}
if (c >= 0x80) {
if (reject8bit) {
/* We have been configured to reject all mail of this
form. */
r = IMAP_MESSAGE_CONTAINS8BIT;
goto ph_error;
} else if (munge8bit) {
/* We have been configured to munge all mail of this
form. */
c = 'X';
}
}
/* just an ordinary character */
buf_putc(&body, c);
}
/* copy this to the output */
if (fout && s != NAME && !skip) fputc(c, fout);
}
/* if we fall off the end of the loop, we hit some sort of error
condition */
ph_error:
/* put the last character back; we'll copy it later */
if (c != EOF) prot_ungetc(c, fin);
/* and we didn't get a header */
if (headname != NULL) *headname = NULL;
if (contents != NULL) *contents = NULL;
return r;
got_header:
/* Note: xstrdup()ing the string ensures we return
* a minimal length string with no allocation slack
* at the end */
if (headname != NULL) *headname = xstrdup(name.s);
if (contents != NULL) *contents = xstrdup(body.s);
return 0;
}
EXPORTED void spool_cache_header(char *name, char *body, hdrcache_t cache)
{
strarray_t *contents;
lcase(name);
contents = (strarray_t *)hash_lookup(name, cache);
if (!contents)
contents = hash_insert(name, strarray_new(), cache);
strarray_appendm(contents, body);
free(name);
}
EXPORTED void spool_replace_header(char *name, char *body, hdrcache_t cache)
{
strarray_t *contents;
lcase(name);
contents = (strarray_t *)hash_lookup(name, cache);
if (!contents)
contents = hash_insert(name, strarray_new(), cache);
else
strarray_truncate(contents, 0);
strarray_appendm(contents, body);
free(name);
}
EXPORTED void spool_remove_header(char *name, hdrcache_t cache)
{
strarray_t *contents;
lcase(name);
contents = (strarray_t *)hash_del(name, cache);
if (contents) strarray_free(contents);
free(name);
}
EXPORTED int spool_fill_hdrcache(struct protstream *fin, FILE *fout, hdrcache_t cache,
const char **skipheaders)
{
int r = 0;
/* let's fill that header cache */
for (;;) {
char *name = NULL, *body = NULL;
if ((r = parseheader(fin, fout, &name, &body, skipheaders)) < 0) {
break;
}
if (!name) {
/* reached the end of headers */
free(body);
break;
}
/* put it in the hash table */
spool_cache_header(name, body, cache);
}
return r;
}
EXPORTED const char **spool_getheader(hdrcache_t cache, const char *phead)
{
char *head;
strarray_t *contents;
assert(cache && phead);
head = xstrdup(phead);
lcase(head);
/* check the cache */
contents = (strarray_t *)hash_lookup(head, cache);
free(head);
return contents ? (const char **)contents->data : NULL;
}
EXPORTED void spool_free_hdrcache(hdrcache_t cache)
{
if (!cache) return;
free_hash_table(cache, (void (*)(void *))strarray_free);
free(cache);
}
struct spool_enum_rock {
void (*proc)(const char *, const char *, void *);
void *rock;
};
static void spool_enum_cb(const char *key, void *data, void *rock)
{
struct spool_enum_rock *c = (struct spool_enum_rock *)rock;
strarray_t *d = (strarray_t *)data;
int i;
for (i = 0; i < d->count; i++) {
const char *val = strarray_nth(d, i);
c->proc(key, val, c->rock);
}
}
EXPORTED void spool_enum_hdrcache(hdrcache_t cache,
void (*proc)(const char *, const char *, void *),
void *rock)
{
struct spool_enum_rock cbrock;
if (!cache) return;
cbrock.proc = proc;
cbrock.rock = rock;
hash_enumerate(cache, spool_enum_cb, &cbrock);
}
/* copies the message from fin to fout, massaging accordingly:
. newlines are fiddled to \r\n
. "." terminates
. embedded NULs are rejected
. bare \r are removed
*/
EXPORTED int spool_copy_msg(struct protstream *fin, FILE *fout)
{
char buf[8192], *p;
int r = 0;
/* -2: Might need room to add a \r\n\0 set */
while (prot_fgets(buf, sizeof(buf)-2, fin)) {
p = buf + strlen(buf) - 1;
if (p < buf) {
/* buffer start with a \0 */
r = IMAP_MESSAGE_CONTAINSNULL;
continue; /* need to eat the rest of the message */
}
else if (buf[0] == '\r' && buf[1] == '\0') {
/* The message contained \r\0, and fgets is confusing us. */
r = IMAP_MESSAGE_CONTAINSNULL;
continue; /* need to eat the rest of the message */
}
else if (p[0] == '\r') {
/*
* We were unlucky enough to get a CR just before we ran
* out of buffer--put it back.
*/
prot_ungetc('\r', fin);
*p = '\0';
}
else if (p[0] == '\n' && (p == buf || p[-1] != '\r')) {
/* found an \n without a \r */
p[0] = '\r';
p[1] = '\n';
p[2] = '\0';
}
else if (p[0] != '\n' && (strlen(buf) < sizeof(buf)-3)) {
/* line contained a \0 not at the end */
r = IMAP_MESSAGE_CONTAINSNULL;
continue;
}
/* Remove any lone CR characters */
while ((p = strchr(buf, '\r')) && p[1] != '\n') {
/* Src/Target overlap, use memmove */
/* strlen(p) will result in copying the NUL byte as well */
memmove(p, p+1, strlen(p));
}
if (buf[0] == '.') {
if (buf[1] == '\r' && buf[2] == '\n') {
/* End of message */
goto dot;
}
/* Remove the dot-stuffing */
if (fout) fputs(buf+1, fout);
} else {
if (fout) fputs(buf, fout);
}
}
/* wow, serious error---got a premature EOF. */
return IMAP_IOERROR;
dot:
return r;
}