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putty-source/ssh1connection.h
Simon Tatham 3214563d8e Convert a lot of 'int' variables to 'bool'.
My normal habit these days, in new code, is to treat int and bool as
_almost_ completely separate types. I'm still willing to use C's
implicit test for zero on an integer (e.g. 'if (!blob.len)' is fine,
no need to spell it out as blob.len != 0), but generally, if a
variable is going to be conceptually a boolean, I like to declare it
bool and assign to it using 'true' or 'false' rather than 0 or 1.

PuTTY is an exception, because it predates the C99 bool, and I've
stuck to its existing coding style even when adding new code to it.
But it's been annoying me more and more, so now that I've decided C99
bool is an acceptable thing to require from our toolchain in the first
place, here's a quite thorough trawl through the source doing
'boolification'. Many variables and function parameters are now typed
as bool rather than int; many assignments of 0 or 1 to those variables
are now spelled 'true' or 'false'.

I managed this thorough conversion with the help of a custom clang
plugin that I wrote to trawl the AST and apply heuristics to point out
where things might want changing. So I've even managed to do a decent
job on parts of the code I haven't looked at in years!

To make the plugin's work easier, I pushed platform front ends
generally in the direction of using standard 'bool' in preference to
platform-specific boolean types like Windows BOOL or GTK's gboolean;
I've left the platform booleans in places they _have_ to be for the
platform APIs to work right, but variables only used by my own code
have been converted wherever I found them.

In a few places there are int values that look very like booleans in
_most_ of the places they're used, but have a rarely-used third value,
or a distinction between different nonzero values that most users
don't care about. In these cases, I've _removed_ uses of 'true' and
'false' for the return values, to emphasise that there's something
more subtle going on than a simple boolean answer:
 - the 'multisel' field in dialog.h's list box structure, for which
   the GTK front end in particular recognises a difference between 1
   and 2 but nearly everything else treats as boolean
 - the 'urgent' parameter to plug_receive, where 1 vs 2 tells you
   something about the specific location of the urgent pointer, but
   most clients only care about 0 vs 'something nonzero'
 - the return value of wc_match, where -1 indicates a syntax error in
   the wildcard.
 - the return values from SSH-1 RSA-key loading functions, which use
   -1 for 'wrong passphrase' and 0 for all other failures (so any
   caller which already knows it's not loading an _encrypted private_
   key can treat them as boolean)
 - term->esc_query, and the 'query' parameter in toggle_mode in
   terminal.c, which _usually_ hold 0 for ESC[123h or 1 for ESC[?123h,
   but can also hold -1 for some other intervening character that we
   don't support.

In a few places there's an integer that I haven't turned into a bool
even though it really _can_ only take values 0 or 1 (and, as above,
tried to make the call sites consistent in not calling those values
true and false), on the grounds that I thought it would make it more
confusing to imply that the 0 value was in some sense 'negative' or
bad and the 1 positive or good:
 - the return value of plug_accepting uses the POSIXish convention of
   0=success and nonzero=error; I think if I made it bool then I'd
   also want to reverse its sense, and that's a job for a separate
   piece of work.
 - the 'screen' parameter to lineptr() in terminal.c, where 0 and 1
   represent the default and alternate screens. There's no obvious
   reason why one of those should be considered 'true' or 'positive'
   or 'success' - they're just indices - so I've left it as int.

ssh_scp_recv had particularly confusing semantics for its previous int
return value: its call sites used '<= 0' to check for error, but it
never actually returned a negative number, just 0 or 1. Now the
function and its call sites agree that it's a bool.

In a couple of places I've renamed variables called 'ret', because I
don't like that name any more - it's unclear whether it means the
return value (in preparation) for the _containing_ function or the
return value received from a subroutine call, and occasionally I've
accidentally used the same variable for both and introduced a bug. So
where one of those got in my way, I've renamed it to 'toret' or 'retd'
(the latter short for 'returned') in line with my usual modern
practice, but I haven't done a thorough job of finding all of them.

Finally, one amusing side effect of doing this is that I've had to
separate quite a few chained assignments. It used to be perfectly fine
to write 'a = b = c = TRUE' when a,b,c were int and TRUE was just a
the 'true' defined by stdbool.h, that idiom provokes a warning from
gcc: 'suggest parentheses around assignment used as truth value'!
2018-11-03 13:45:00 +00:00

120 lines
3.8 KiB
C

struct ssh1_channel;
struct outstanding_succfail;
struct ssh1_connection_state {
int crState;
Ssh *ssh;
Conf *conf;
int local_protoflags, remote_protoflags;
tree234 *channels; /* indexed by local id */
/* In SSH-1, the main session doesn't take the form of a 'channel'
* according to the wire protocol. But we want to use the same API
* for it, so we define an SshChannel here - but one that uses a
* separate vtable from the usual one, so it doesn't map to a
* struct ssh1_channel as all the others do. */
SshChannel mainchan_sc;
Channel *mainchan_chan; /* the other end of mainchan_sc */
mainchan *mainchan; /* and its subtype */
bool got_pty;
bool ldisc_opts[LD_N_OPTIONS];
bool stdout_throttling;
bool want_user_input;
bool session_terminated;
int term_width, term_height, term_width_orig, term_height_orig;
bool X11_fwd_enabled;
struct X11Display *x11disp;
struct X11FakeAuth *x11auth;
tree234 *x11authtree;
bool agent_fwd_enabled;
tree234 *rportfwds;
PortFwdManager *portfwdmgr;
bool portfwdmgr_configured;
bool finished_setup;
/*
* These store the list of requests that we're waiting for
* SSH_SMSG_{SUCCESS,FAILURE} replies to. (Those messages don't
* come with any indication of what they're in response to, so we
* have to keep track of the queue ourselves.)
*/
struct outstanding_succfail *succfail_head, *succfail_tail;
bool compressing; /* used in server mode only */
ConnectionLayer cl;
PacketProtocolLayer ppl;
};
struct ssh1_channel {
struct ssh1_connection_state *connlayer;
unsigned remoteid, localid;
int type;
/* True if we opened this channel but server hasn't confirmed. */
bool halfopen;
/* Bitmap of whether we've sent/received CHANNEL_CLOSE and
* CHANNEL_CLOSE_CONFIRMATION. */
#define CLOSES_SENT_CLOSE 1
#define CLOSES_SENT_CLOSECONF 2
#define CLOSES_RCVD_CLOSE 4
#define CLOSES_RCVD_CLOSECONF 8
int closes;
/*
* This flag indicates that an EOF is pending on the outgoing side
* of the channel: that is, wherever we're getting the data for
* this channel has sent us some data followed by EOF. We can't
* actually send the EOF until we've finished sending the data, so
* we set this flag instead to remind us to do so once our buffer
* is clear.
*/
bool pending_eof;
/*
* True if this channel is causing the underlying connection to be
* throttled.
*/
bool throttling_conn;
/*
* True if we currently have backed-up data on the direction of
* this channel pointing out of the SSH connection, and therefore
* would prefer the 'Channel' implementation not to read further
* local input if possible.
*/
bool throttled_by_backlog;
Channel *chan; /* handle the client side of this channel, if not */
SshChannel sc; /* entry point for chan to talk back to */
};
SshChannel *ssh1_session_open(ConnectionLayer *cl, Channel *chan);
void ssh1_channel_init(struct ssh1_channel *c);
void ssh1_channel_free(struct ssh1_channel *c);
struct ssh_rportfwd *ssh1_rportfwd_alloc(
ConnectionLayer *cl,
const char *shost, int sport, const char *dhost, int dport,
int addressfamily, const char *log_description, PortFwdRecord *pfr,
ssh_sharing_connstate *share_ctx);
SshChannel *ssh1_serverside_x11_open(
ConnectionLayer *cl, Channel *chan, const SocketPeerInfo *pi);
SshChannel *ssh1_serverside_agent_open(ConnectionLayer *cl, Channel *chan);
void ssh1_connection_direction_specific_setup(
struct ssh1_connection_state *s);
bool ssh1_handle_direction_specific_packet(
struct ssh1_connection_state *s, PktIn *pktin);
bool ssh1_check_termination(struct ssh1_connection_state *s);