commit 9e15ab4a5a2938318816f3972708176462cb9d5f
Author: Oswald Buddenhagen <[email protected]>
Date: Sun Feb 15 12:15:46 2015 +0100
refactor socket EOF handling
handling EOF already at the socket level isn't a very good idea - it
breaks the abstraction, and makes implementing sane semantics hard.
src/drv_imap.c | 32 ++++++++++++++++++++++++++------
src/socket.c | 29 +++++++++++++++++++++--------
src/socket.h | 9 ---------
3 files changed, 47 insertions(+), 23 deletions(-)
diff --git a/src/drv_imap.c b/src/drv_imap.c
index 447bc6e..7146d26 100644
--- a/src/drv_imap.c
+++ b/src/drv_imap.c
@@ -114,6 +114,8 @@ typedef struct imap_store {
/* Used during sequential operations like connect */
enum { GreetingPending = 0, GreetingBad, GreetingOk, GreetingPreauth }
greeting;
+ int expectBYE; /* LOGOUT is in progress */
+ int expectEOF; /* received LOGOUT's OK or unsolicited BYE */
int canceling; /* imap_cancel() is in progress */
union {
void (*imap_open)( store_t *srv, void *aux );
@@ -674,7 +676,7 @@ parse_imap_list( imap_store_t *ctx, char **sp,
parse_list_state_t *sts )
{
list_t *cur, **curp;
char *s = *sp, *d, *p;
- int bytes;
+ int n, bytes;
char c;
assert( sts );
@@ -724,7 +726,13 @@ parse_imap_list( imap_store_t *ctx, char **sp,
parse_list_state_t *sts )
s[cur->len] = 0;
getbytes:
- bytes -= socket_read( &ctx->conn, s, bytes );
+ n = socket_read( &ctx->conn, s, bytes );
+ if (n < 0) {
+ badeof:
+ error( "IMAP error: unexpected EOF from %s\n",
ctx->conn.name );
+ goto bail;
+ }
+ bytes -= n;
if (bytes > 0)
goto postpone;
@@ -738,6 +746,8 @@ parse_imap_list( imap_store_t *ctx, char **sp,
parse_list_state_t *sts )
getline:
if (!(s = socket_read_line( &ctx->conn )))
goto postpone;
+ if (s == (void *)~0)
+ goto badeof;
if (DFlags & VERBOSE) {
printf( "%s%s\n", ctx->label, s );
fflush( stdout );
@@ -1218,6 +1228,12 @@ imap_socket_read( void *aux )
}
if (!(cmd = socket_read_line( &ctx->conn )))
return;
+ if (cmd == (void *)~0) {
+ if (!ctx->expectEOF)
+ error( "IMAP error: unexpected EOF from %s\n",
ctx->conn.name );
+ /* A clean shutdown sequence ends with bad_callback as
well (see imap_cleanup()). */
+ break;
+ }
if (DFlags & VERBOSE) {
printf( "%s%s\n", ctx->label, cmd );
fflush( stdout );
@@ -1250,12 +1266,14 @@ imap_socket_read( void *aux )
goto dogreet;
}
} else if (!strcmp( "BYE", arg )) {
- if (ctx->conn.state != SCK_CLOSING) {
- ctx->conn.state = SCK_CLOSING;
+ if (!ctx->expectBYE) {
ctx->greeting = GreetingBad;
error( "IMAP error: unexpected BYE
response: %s\n", cmd );
+ /* We just wait for the server to close
the connection now. */
+ ctx->expectEOF = 1;
+ } else {
+ /* We still need to wait for the
LOGOUT's tagged OK. */
}
- /* We just wait for the server to close the
connection now. */
} else if (ctx->greeting == GreetingPending) {
error( "IMAP error: bogus greeting response
%s\n", arg );
break;
@@ -1470,7 +1488,7 @@ imap_cleanup( void )
for (ctx = unowned; ctx; ctx = nctx) {
nctx = ctx->next;
set_bad_callback( ctx, (void (*)(void *))imap_cancel_store, ctx
);
- ((imap_store_t *)ctx)->conn.state = SCK_CLOSING;
+ ((imap_store_t *)ctx)->expectBYE = 1;
imap_exec( (imap_store_t *)ctx, 0, imap_cleanup_p2, "LOGOUT" );
}
}
@@ -1481,6 +1499,8 @@ imap_cleanup_p2( imap_store_t *ctx,
{
if (response == RESP_NO)
imap_cancel_store( &ctx->gen );
+ else if (response == RESP_OK)
+ ctx->expectEOF = 1;
}
/******************* imap_open_store *******************/
diff --git a/src/socket.c b/src/socket.c
index d70488a..9452cd0 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -43,6 +43,15 @@
# include <openssl/x509v3.h>
#endif
+enum {
+ SCK_CONNECTING,
+#ifdef HAVE_LIBSSL
+ SCK_STARTTLS,
+#endif
+ SCK_READY,
+ SCK_EOF
+};
+
static void
socket_fail( conn_t *conn )
{
@@ -67,11 +76,12 @@ ssl_return( const char *func, conn_t *conn, int ret )
case SSL_ERROR_SSL:
if (!(err = ERR_get_error())) {
if (ret == 0) {
- if (conn->state != SCK_CLOSING)
- error( "Socket error: secure %s %s:
unexpected EOF\n", func, conn->name );
- } else {
- sys_error( "Socket error: secure %s %s", func,
conn->name );
+ /* Callers take the short path out, so signal
higher layers from here. */
+ conn->state = SCK_EOF;
+ conn->read_callback( conn->callback_aux );
+ return 0;
}
+ sys_error( "Socket error: secure %s %s", func,
conn->name );
} else {
error( "Socket error: secure %s %s: %s\n", func,
conn->name, ERR_error_string( err, 0 ) );
}
@@ -582,10 +592,9 @@ do_read( conn_t *sock, char *buf, int len )
sys_error( "Socket error: read from %s", sock->name );
socket_fail( sock );
} else if (!n) {
- if (sock->state != SCK_CLOSING)
- error( "Socket error: read from %s: unexpected
EOF\n", sock->name );
- socket_fail( sock );
- return -1;
+ /* EOF. Callers take the short path out, so signal
higher layers from here. */
+ sock->state = SCK_EOF;
+ sock->read_callback( sock->callback_aux );
}
}
@@ -656,6 +665,8 @@ int
socket_read( conn_t *conn, char *buf, int len )
{
int n = conn->bytes;
+ if (!n && conn->state == SCK_EOF)
+ return -1;
if (n > len)
n = len;
memcpy( buf, conn->buf + conn->offset, n );
@@ -680,6 +691,8 @@ socket_read_line( conn_t *b )
memmove( b->buf, b->buf + b->offset, b->bytes );
b->offset = 0;
}
+ if (b->state == SCK_EOF)
+ return (void *)~0;
return 0;
}
n = p + 1 - s;
diff --git a/src/socket.h b/src/socket.h
index 20c3033..a420e49 100644
--- a/src/socket.h
+++ b/src/socket.h
@@ -29,15 +29,6 @@
#include <zlib.h>
#endif
-enum {
- SCK_CONNECTING,
-#ifdef HAVE_LIBSSL
- SCK_STARTTLS,
-#endif
- SCK_READY,
- SCK_CLOSING
-};
-
#ifdef HAVE_LIBSSL
typedef struct ssl_st SSL;
typedef struct ssl_ctx_st SSL_CTX;
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