commit 8ab42c2fc6e9b0e8a336538e6cff3f7be4a57f4d
Author: Oswald Buddenhagen <o...@kde.org>
Date: Sun Apr 3 18:47:37 2011 +0200
decouple the filling of the read buffer from consuming it
this prepares the code for being called from a callback.
notably, this makes the imap list parser have a "soft stack", so the
recursion can be suspended at any time.
src/drv_imap.c | 143 ++++++++++++++++++++++++++++++------------------
src/isync.h | 11 ++--
src/socket.c | 108 ++++++++++++++++++------------------
3 files changed, 150 insertions(+), 112 deletions(-)
diff --git a/src/drv_imap.c b/src/drv_imap.c
index 2d922dc..71c432f 100644
--- a/src/drv_imap.c
+++ b/src/drv_imap.c
@@ -67,6 +67,13 @@ typedef struct _list {
int len;
} list_t;
+#define MAX_LIST_DEPTH 5
+
+typedef struct parse_list_state {
+ list_t *head, **stack[MAX_LIST_DEPTH];
+ int level, need_bytes;
+} parse_list_state_t;
+
struct imap_cmd;
typedef struct imap_store {
@@ -79,6 +86,7 @@ typedef struct imap_store {
list_t *ns_personal, *ns_other, *ns_shared; /* NAMESPACE info */
message_t **msgapp; /* FETCH results */
unsigned caps; /* CAPABILITY results */
+ parse_list_state_t parse_list_sts;
/* command queue */
int nexttag, num_in_progress, literal_pending;
struct imap_cmd *in_progress, **in_progress_append;
@@ -433,66 +441,76 @@ free_list( list_t *list )
}
}
+enum {
+ LIST_OK,
+ LIST_PARTIAL,
+ LIST_BAD
+};
+
static int
-parse_imap_list_l( imap_store_t *ctx, char **sp, list_t **curp, int level )
+parse_imap_list( imap_store_t *ctx, char **sp, parse_list_state_t *sts )
{
- list_t *cur;
+ list_t *cur, **curp;
char *s = *sp, *p;
- int n, bytes;
+ int bytes;
+
+ assert( sts );
+ assert( sts->level > 0 );
+ curp = sts->stack[--sts->level];
+ bytes = sts->need_bytes;
+ if (bytes >= 0) {
+ sts->need_bytes = -1;
+ if (!bytes)
+ goto getline;
+ cur = (list_t *)((char *)curp - offsetof(list_t, next));
+ s = cur->val + cur->len - bytes;
+ goto getbytes;
+ }
for (;;) {
while (isspace( (unsigned char)*s ))
s++;
- if (level && *s == ')') {
+ if (sts->level && *s == ')') {
s++;
- break;
+ curp = sts->stack[--sts->level];
+ goto next;
}
*curp = cur = nfmalloc( sizeof(*cur) );
- curp = &cur->next;
cur->val = 0; /* for clean bail */
+ curp = &cur->next;
+ *curp = 0; /* ditto */
if (*s == '(') {
/* sublist */
+ if (sts->level == MAX_LIST_DEPTH)
+ goto bail;
s++;
cur->val = LIST;
- if (parse_imap_list_l( ctx, &s, &cur->child, level + 1
))
- goto bail;
+ sts->stack[sts->level++] = curp;
+ curp = &cur->child;
+ *curp = 0; /* for clean bail */
+ goto next2;
} else if (ctx && *s == '{') {
/* literal */
bytes = cur->len = strtol( s + 1, &s, 10 );
- if (*s != '}')
+ if (*s != '}' || *++s)
goto bail;
s = cur->val = nfmalloc( cur->len );
- /* dump whats left over in the input buffer */
- n = ctx->conn.bytes - ctx->conn.offset;
-
- if (n > bytes)
- /* the entire message fit in the buffer */
- n = bytes;
-
- memcpy( s, ctx->conn.buf + ctx->conn.offset, n );
- s += n;
- bytes -= n;
+ getbytes:
+ bytes -= socket_read( &ctx->conn, s, bytes );
+ if (bytes > 0)
+ goto postpone;
- /* mark that we used part of the buffer */
- ctx->conn.offset += n;
-
- /* now read the rest of the message */
- while (bytes > 0) {
- if ((n = socket_read( &ctx->conn, s, bytes ))
<= 0)
- goto bail;
- s += n;
- bytes -= n;
- }
if (DFlags & XVERBOSE) {
puts( "=========" );
fwrite( cur->val, cur->len, 1, stdout );
puts( "=========" );
}
- if (buffer_gets( &ctx->conn, &s ))
- goto bail;
+ getline:
+ if (!(s = socket_read_line( &ctx->conn )))
+ goto postpone;
} else if (*s == '"') {
/* quoted string */
s++;
@@ -509,7 +527,7 @@ parse_imap_list_l( imap_store_t *ctx, char **sp, list_t
**curp, int level )
/* atom */
p = s;
for (; *s && !isspace( (unsigned char)*s ); s++)
- if (level && *s == ')')
+ if (sts->level && *s == ')')
break;
cur->len = s - p;
if (cur->len == 3 && !memcmp ("NIL", p, 3))
@@ -521,41 +539,50 @@ parse_imap_list_l( imap_store_t *ctx, char **sp, list_t
**curp, int level )
}
}
- if (!level)
+ next:
+ if (!sts->level)
break;
+ next2:
if (!*s)
goto bail;
}
*sp = s;
- *curp = 0;
- return 0;
+ return LIST_OK;
+ postpone:
+ if (sts->level < MAX_LIST_DEPTH) {
+ sts->stack[sts->level++] = curp;
+ sts->need_bytes = bytes;
+ return LIST_PARTIAL;
+ }
bail:
- *curp = 0;
- return -1;
+ free_list( sts->head );
+ return LIST_BAD;
}
-static list_t *
-parse_imap_list( imap_store_t *ctx, char **sp )
+static void
+parse_list_init( parse_list_state_t *sts )
{
- list_t *head;
-
- if (!parse_imap_list_l( ctx, sp, &head, 0 ))
- return head;
- free_list( head );
- return NULL;
+ sts->need_bytes = -1;
+ sts->level = 1;
+ sts->head = 0;
+ sts->stack[0] = &sts->head;
}
static list_t *
parse_list( char **sp )
{
- return parse_imap_list( 0, sp );
+ parse_list_state_t sts;
+ parse_list_init( &sts );
+ if (parse_imap_list( 0, sp, &sts ) == LIST_OK)
+ return sts.head;
+ return NULL;
}
static int
-parse_fetch( imap_store_t *ctx, char *cmd ) /* move this down */
+parse_fetch( imap_store_t *ctx, list_t *list )
{
- list_t *tmp, *list, *flags;
+ list_t *tmp, *flags;
char *body = 0;
imap_message_t *cur;
msg_data_t *msgdata;
@@ -563,8 +590,6 @@ parse_fetch( imap_store_t *ctx, char *cmd ) /* move this
down */
int uid = 0, mask = 0, status = 0, size = 0;
unsigned i;
- list = parse_imap_list( ctx, &cmd );
-
if (!is_list( list )) {
error( "IMAP error: bogus FETCH response\n" );
free_list( list );
@@ -784,8 +809,11 @@ get_cmd_result( imap_store_t *ctx, struct imap_cmd *tcmd )
greeted = ctx->greeting;
for (;;) {
- if (buffer_gets( &ctx->conn, &cmd ))
- break;
+ if (!(cmd = socket_read_line( &ctx->conn ))) {
+ if (socket_fill( &ctx->conn ) < 0)
+ break;
+ continue;
+ }
arg = next_arg( &cmd );
if (*arg == '*') {
@@ -820,8 +848,17 @@ get_cmd_result( imap_store_t *ctx, struct imap_cmd *tcmd )
else if (!strcmp( "RECENT", arg1 ))
ctx->gen.recent = atoi( arg );
else if(!strcmp ( "FETCH", arg1 )) {
- if (parse_fetch( ctx, cmd ))
+ parse_list_init( &ctx->parse_list_sts );
+ do_fetch:
+ if ((resp = parse_imap_list( ctx, &cmd,
&ctx->parse_list_sts )) == LIST_BAD)
break; /* stream is likely to
be useless now */
+ if (resp == LIST_PARTIAL) {
+ if (socket_fill( &ctx->conn ) <
0)
+ break;
+ goto do_fetch;
+ }
+ if (parse_fetch( ctx,
ctx->parse_list_sts.head ) < 0)
+ break; /* this may mean
anything, so prefer not to spam the log */
}
} else {
error( "IMAP error: unrecognized untagged
response '%s'\n", arg );
diff --git a/src/isync.h b/src/isync.h
index c074f56..7de6f33 100644
--- a/src/isync.h
+++ b/src/isync.h
@@ -79,8 +79,9 @@ typedef struct {
SSL *ssl;
#endif
- int bytes;
- int offset;
+ int offset; /* start of filled bytes in buffer */
+ int bytes; /* number of filled bytes in buffer */
+ int scanoff; /* offset to continue scanning for newline at, relative to
'offset' */
char buf[1024];
} conn_t;
@@ -332,13 +333,13 @@ extern const char *Home;
int socket_connect( const server_conf_t *conf, conn_t *sock );
int socket_start_tls( const server_conf_t *conf, conn_t *sock );
void socket_close( conn_t *sock );
-int socket_read( conn_t *sock, char *buf, int len );
+int socket_fill( conn_t *sock );
+int socket_read( conn_t *sock, char *buf, int len ); /* never waits */
+char *socket_read_line( conn_t *sock ); /* don't free return value; never
waits */
typedef enum { KeepOwn = 0, GiveOwn } ownership_t;
int socket_write( conn_t *sock, char *buf, int len, ownership_t takeOwn );
int socket_pending( conn_t *sock );
-int buffer_gets( conn_t *b, char **s );
-
void cram( const char *challenge, const char *user, const char *pass,
char **_final, int *_finallen );
diff --git a/src/socket.c b/src/socket.c
index b2a1ee9..076c075 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -354,11 +354,17 @@ socket_close( conn_t *sock )
}
int
-socket_read( conn_t *sock, char *buf, int len )
+socket_fill( conn_t *sock )
{
- int n;
-
+ char *buf;
+ int n = sock->offset + sock->bytes;
+ int len = sizeof(sock->buf) - n;
+ if (!len) {
+ error( "Socket error: receive buffer full. Probably protocol
error.\n" );
+ return -1;
+ }
assert( sock->fd >= 0 );
+ buf = sock->buf + n;
n =
#ifdef HAVE_LIBSSL
sock->ssl ? SSL_read( sock->ssl, buf, len ) :
@@ -368,10 +374,55 @@ socket_read( conn_t *sock, char *buf, int len )
socket_perror( "read", sock, n );
close( sock->fd );
sock->fd = -1;
+ return -1;
+ } else {
+ sock->bytes += n;
+ return 0;
}
+}
+
+int
+socket_read( conn_t *conn, char *buf, int len )
+{
+ int n = conn->bytes;
+ if (n > len)
+ n = len;
+ memcpy( buf, conn->buf + conn->offset, n );
+ if (!(conn->bytes -= n))
+ conn->offset = 0;
+ else
+ conn->offset += n;
return n;
}
+char *
+socket_read_line( conn_t *b )
+{
+ char *p, *s;
+ int n;
+
+ s = b->buf + b->offset;
+ p = memchr( s + b->scanoff, '\n', b->bytes - b->scanoff );
+ if (!p) {
+ b->scanoff = b->bytes;
+ if (b->offset + b->bytes == sizeof(b->buf)) {
+ memmove( b->buf, b->buf + b->offset, b->bytes );
+ b->offset = 0;
+ }
+ return 0;
+ }
+ n = p + 1 - s;
+ b->offset += n;
+ b->bytes -= n;
+ b->scanoff = 0;
+ if (p != s && p[-1] == '\r')
+ p--;
+ *p = 0;
+ if (DFlags & VERBOSE)
+ puts( s );
+ return s;
+}
+
int
socket_write( conn_t *sock, char *buf, int len, ownership_t takeOwn )
{
@@ -410,57 +461,6 @@ socket_pending( conn_t *sock )
return 0;
}
-/* simple line buffering */
-int
-buffer_gets( conn_t *b, char **s )
-{
- int n;
- int start = b->offset;
-
- *s = b->buf + start;
-
- for (;;) {
- /* make sure we have enough data to read the \r\n sequence */
- if (b->offset + 1 >= b->bytes) {
- if (start) {
- /* shift down used bytes */
- *s = b->buf;
-
- assert( start <= b->bytes );
- n = b->bytes - start;
-
- if (n)
- memmove( b->buf, b->buf + start, n );
- b->offset -= start;
- b->bytes = n;
- start = 0;
- }
-
- n = socket_read( b, b->buf + b->bytes,
- sizeof(b->buf) - b->bytes );
-
- if (n <= 0)
- return -1;
-
- b->bytes += n;
- }
-
- if (b->buf[b->offset] == '\r') {
- assert( b->offset + 1 < b->bytes );
- if (b->buf[b->offset + 1] == '\n') {
- b->buf[b->offset] = 0; /* terminate the string
*/
- b->offset += 2; /* next line */
- if (DFlags & VERBOSE)
- puts( *s );
- return 0;
- }
- }
-
- b->offset++;
- }
- /* not reached */
-}
-
#ifdef HAVE_LIBSSL
/* this isn't strictly socket code, but let's have all OpenSSL use in one
file. */
------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and
threat landscape has changed and how IT managers can respond. Discussions
will include endpoint security, mobile security and the latest in malware
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________
isync-devel mailing list
isync-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/isync-devel
