site: Pass msg into enter_new_state

The rules for when this is initialised, in site_incoming, are a
slightly complicated, so document them.

Examination of these rules reveals that the msg argument to
process_msg1 should be const, since process_msg1 (unlike the other
process_msgN functions) receives this, rather than generating it.

No functional change.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/site.c b/site.c
index 9c320a5b31013077cfddaca9842726e3d79dc39e..bdc948a06dac5c896fb4fba3a1490ff140249a24 100644 (file)
--- a/site.c
+++ b/site.c
@@ -109,6 +109,8 @@
 
 #define CASES_MSG3_KNOWN LABEL_MSG3: case LABEL_MSG3BIS
 
+struct msg;
+
 int32_t site_max_start_pad = 4*4;
 
 static cstring_t state_name(uint32_t state)
@@ -457,7 +459,9 @@ static bool_t initiate_key_setup(struct site *st, cstring_t reason,
 static void enter_state_run(struct site *st);
 static bool_t enter_state_resolve(struct site *st);
 static void decrement_resolving_count(struct site *st, int by);
-static bool_t enter_new_state(struct site *st,uint32_t next);
+static bool_t enter_new_state(struct site *st,uint32_t next,
+                             const struct msg *prompt
+                             /* may be 0 for SENTMSG1 */);
 static void enter_state_wait(struct site *st);
 static void activate_new_key(struct site *st);
 
@@ -799,7 +803,8 @@ static bool_t generate_msg1(struct site *st)
 }
 
 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
-                          const struct comm_addr *src, struct msg *m)
+                          const struct comm_addr *src,
+                          const struct msg *m)
 {
     /* We've already determined we're in an appropriate state to
        process an incoming MSG1, and that the MSG1 has correct values
@@ -1352,7 +1357,7 @@ static void decrement_resolving_count(struct site *st, int by)
     switch (st->state) {
     case SITE_RESOLVE:
         if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
-           enter_new_state(st,SITE_SENTMSG1);
+           enter_new_state(st,SITE_SENTMSG1,0);
        } else {
            /* Can't figure out who to try to to talk to */
            slog(st,LOG_SETUP_INIT,
@@ -1412,7 +1417,7 @@ static bool_t initiate_key_setup(struct site *st, cstring_t reason,
        slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
        return enter_state_resolve(st);
     } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
-       return enter_new_state(st,SITE_SENTMSG1);
+       return enter_new_state(st,SITE_SENTMSG1,0);
     }
     slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
     return False;
@@ -1566,9 +1571,11 @@ static bool_t enter_state_resolve(struct site *st)
     return ensure_resolving(st);
 }
 
-static bool_t enter_new_state(struct site *st, uint32_t next)
+static bool_t enter_new_state(struct site *st, uint32_t next,
+                             const struct msg *prompt
+                             /* may be 0 for SENTMSG1 */)
 {
-    bool_t (*gen)(struct site *st);
+    bool_t (*gen)(struct site *st, struct msg *prompt);
     int r;
 
     slog(st,LOG_STATE,"entering state %s",state_name(next));
@@ -1850,6 +1857,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
     uint32_t dest=get_uint32(buf->start);
     uint32_t msgtype=get_uint32(buf->start+8);
     struct msg msg;
+      /* initialised by named_for_us, or process_msgN for N!=1 */
 
     if (msgtype==LABEL_MSG1) {
        if (!named_for_us(st,buf,msgtype,&msg))
@@ -1862,7 +1870,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
            transport_compute_setupinit_peers(st,0,0,source);
            if (process_msg1(st,buf,source,&msg)) {
                slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
-               bool_t entered=enter_new_state(st,SITE_SENTMSG2);
+               bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
                if (entered && st->addresses && st->local_mobile)
                    /* We must do this as the very last thing, because
                       the resolver callback might reenter us. */
@@ -1888,7 +1896,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
                if (process_msg1(st,buf,source,&msg)) {
                    BUF_FREE(&st->buffer); /* Free our old message 1 */
                    transport_setup_msgok(st,source);
-                   enter_new_state(st,SITE_SENTMSG2);
+                   enter_new_state(st,SITE_SENTMSG2,&msg);
                } else {
                    slog(st,LOG_ERROR,"failed to process an incoming "
                         "crossed msg1 (we have low priority)");
@@ -1962,7 +1970,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
                slog(st,LOG_UNEXPECTED,"unexpected MSG2");
            } else if (process_msg2(st,buf,source,&msg)) {
                transport_setup_msgok(st,source);
-               enter_new_state(st,SITE_SENTMSG3);
+               enter_new_state(st,SITE_SENTMSG3,&msg);
            } else {
                slog(st,LOG_SEC,"invalid MSG2");
            }
@@ -1976,7 +1984,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
                slog(st,LOG_UNEXPECTED,"unexpected MSG3");
            } else if (process_msg3(st,buf,source,msgtype,&msg)) {
                transport_setup_msgok(st,source);
-               enter_new_state(st,SITE_SENTMSG4);
+               enter_new_state(st,SITE_SENTMSG4,&msg);
            } else {
                slog(st,LOG_SEC,"invalid MSG3");
            }
@@ -1990,7 +1998,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
                slog(st,LOG_UNEXPECTED,"unexpected MSG4");
            } else if (process_msg4(st,buf,source,&msg)) {
                transport_setup_msgok(st,source);
-               enter_new_state(st,SITE_SENTMSG5);
+               enter_new_state(st,SITE_SENTMSG5,&msg);
            } else {
                slog(st,LOG_SEC,"invalid MSG4");
            }
@@ -2005,7 +2013,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
            if (st->state==SITE_SENTMSG4) {
                if (process_msg5(st,buf,source,st->new_transform)) {
                    transport_setup_msgok(st,source);
-                   enter_new_state(st,SITE_RUN);
+                   enter_new_state(st,SITE_RUN,&msg);
                } else {
                    slog(st,LOG_SEC,"invalid MSG5");
                }