udp, util: Break out send_nak function

Move the code in udp.c which constructs NAKs into its own function
in util.c.  This will make it easier to reuse.

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

diff --git a/udp.c b/udp.c
index c83e618..483ed37 100644 (file)
--- a/udp.c
+++ b/udp.c
@@ -121,12 +121,12 @@ static void udp_afterpoll(void *state, struct pollfd *fds, int nfds)
                    buf_unprepend(st->rbuf,2);
                    memcpy(&from.sin_port,buf_unprepend(st->rbuf,2),2);
                }
+               struct comm_addr ca;
+               FILLZERO(ca);
+               ca.comm=&st->ops;
+               ca.sin=from;
                done=False;
                for (n=st->notify; n; n=n->next) {
-                   struct comm_addr ca;
-                   FILLZERO(ca);
-                   ca.comm=&st->ops;
-                   ca.sin=from;
                    if (n->fn(n->state, st->rbuf, &ca)) {
                        done=True;
                        break;
@@ -141,17 +141,7 @@ static void udp_afterpoll(void *state, struct pollfd *fds, int nfds)
                        /* Manufacture and send NAK packet */
                        source=get_uint32(st->rbuf->start); /* Us */
                        dest=get_uint32(st->rbuf->start+4); /* Them */
-                       Message(M_INFO,"udp (port %d, peer %s):"
-                               " %08"PRIx32"<-%08"PRIx32": %08"PRIx32":"
-                               " unwanted/incorrect, sending NAK\n",
-                               st->port, saddr_to_string(&from),
-                               dest, source, msgtype);
-                       buffer_init(st->rbuf,0);
-                       buf_append_uint32(st->rbuf,dest);
-                       buf_append_uint32(st->rbuf,source);
-                       buf_append_uint32(st->rbuf,LABEL_NAK);
-                       sendto(st->fd, st->rbuf->start, st->rbuf->size, 0,
-                              (struct sockaddr *)&from, sizeof(from));
+                       send_nak(&ca,source,dest,msgtype,st->rbuf,"unwanted");
                    }
                    BUF_FREE(st->rbuf);
                }

diff --git a/util.c b/util.c
index 3d11987..1b46bc0 100644 (file)
--- a/util.c
+++ b/util.c
@@ -38,6 +38,7 @@
 #include <sys/wait.h>
 #include "util.h"
 #include "unaligned.h"
+#include "magic.h"
 
 #define MIN_BUFFER_SIZE 64
 #define DEFAULT_BUFFER_SIZE 4096
@@ -381,6 +382,22 @@ static list_t *buffer_apply(closure_t *self, struct cloc loc, dict_t *context,
     return new_closure(&st->cl);
 }
 
+void send_nak(const struct comm_addr *dest, uint32_t our_index,
+             uint32_t their_index, uint32_t msgtype,
+             struct buffer_if *buf, const char *logwhy)
+{
+    buffer_init(buf,dest->comm->min_start_pad);
+    buf_append_uint32(buf,their_index);
+    buf_append_uint32(buf,our_index);
+    buf_append_uint32(buf,LABEL_NAK);
+    if (logwhy)
+       Message(M_INFO,"%s: %08"PRIx32"<-%08"PRIx32": %08"PRIx32":"
+               " %s; sending NAK\n",
+               dest->comm->addr_to_string(dest->comm->st,dest),
+               our_index, their_index, msgtype, logwhy);
+    dest->comm->sendmsg(dest->comm->st, buf, dest);
+}
+
 int consttime_memeq(const void *s1in, const void *s2in, size_t n)
 {
     const uint8_t *s1=s1in, *s2=s2in;

diff --git a/util.h b/util.h
index cbe9f52..816c056 100644 (file)
--- a/util.h
+++ b/util.h
@@ -45,6 +45,10 @@ extern int32_t write_mpbin(MP_INT *a, uint8_t *buffer, int32_t buflen);
 
 extern struct log_if *init_log(list_t *loglist);
 
+extern void send_nak(const struct comm_addr *dest, uint32_t our_index,
+                    uint32_t their_index, uint32_t msgtype,
+                    struct buffer_if *buf, const char *logwhy);
+
 extern int consttime_memeq(const void *s1, const void *s2, size_t n);
 
 #endif /* util_h */