X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=secnet.git;a=blobdiff_plain;f=util.c;h=cfaefd227148c5f908f707b6f0b31ba48f21037c;hp=63fe76f4451a80e2a6c266fffb8c1aabd878d20f;hb=1ce2f8bc69bc1bef98b48f450081d96e2c29cc00;hpb=7b1a9fb74228564b5ee07b48c042ee7b9a2260f1

diff --git a/util.c b/util.c
index 63fe76f..cfaefd2 100644
--- 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
@@ -228,8 +229,9 @@ void buffer_assert_free(struct buffer_if *buffer, cstring_t file,
 			int line)
 {
     if (!buffer->free) {
-	fatal("BUF_ASSERT_FREE, %s line %d, owned by %s",
-	      file,line,buffer->owner);
+	fprintf(stderr,"secnet: BUF_ASSERT_FREE, %s line %d, owned by %s",
+		file,line,buffer->owner);
+	assert(!"buffer_assert_free failure");
     }
 }
 
@@ -237,13 +239,15 @@ void buffer_assert_used(struct buffer_if *buffer, cstring_t file,
 			int line)
 {
     if (buffer->free) {
-	fatal("BUF_ASSERT_USED, %s line %d, last owned by %s",
-	      file,line,buffer->owner);
+	fprintf(stderr,"secnet: BUF_ASSERT_USED, %s line %d, last owned by %s",
+		file,line,buffer->owner);
+	assert(!"buffer_assert_used failure");
     }
 }
 
 void buffer_init(struct buffer_if *buffer, int32_t max_start_pad)
 {
+    assert(max_start_pad<=buffer->len);
     buffer->start=buffer->base+max_start_pad;
     buffer->size=0;
 }
@@ -269,6 +273,7 @@ void *buf_unappend(struct buffer_if *buf, int32_t amount) {
 
 void *buf_unprepend(struct buffer_if *buf, int32_t amount) {
     void *p;
+    if (buf->size < amount) return 0;
     p=buf->start;
     buf->start+=amount;
     buf->size-=amount;
@@ -300,6 +305,34 @@ void buffer_new(struct buffer_if *buf, int32_t len)
     buf->base=safe_malloc(len,"buffer_new");
 }
 
+void buffer_readonly_view(struct buffer_if *buf, const void *data, int32_t len)
+{
+    buf->free=False;
+    buf->owner="READONLY";
+    buf->flags=0;
+    buf->loc.file=NULL;
+    buf->loc.line=0;
+    buf->size=buf->len=len;
+    buf->base=buf->start=(uint8_t*)data;
+}
+
+void buffer_readonly_clone(struct buffer_if *out, const struct buffer_if *in)
+{
+    buffer_readonly_view(out,in->start,in->size);
+}
+
+void buffer_copy(struct buffer_if *dst, const struct buffer_if *src)
+{
+    if (dst->len < src->len) {
+	dst->base=realloc(dst->base,src->len);
+	if (!dst->base) fatal_perror("buffer_copy");
+	dst->len = src->len;
+    }
+    dst->start = dst->base + (src->start - src->base);
+    dst->size = src->size;
+    memcpy(dst->start, src->start, dst->size);
+}
+
 static list_t *buffer_apply(closure_t *self, struct cloc loc, dict_t *context,
 			    list_t *args)
 {
@@ -350,6 +383,38 @@ 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;
+    register volatile uint8_t accumulator=0;
+
+    while (n-- > 0) {
+	accumulator |= (*s1++ ^ *s2++);
+    }
+    accumulator |= accumulator >> 4; /* constant-time             */
+    accumulator |= accumulator >> 2; /*  boolean canonicalisation */
+    accumulator |= accumulator >> 1;
+    accumulator &= 1;
+    accumulator ^= 1;
+    return accumulator;
+}
+
 void util_module(dict_t *dict)
 {
     add_closure(dict,"sysbuffer",buffer_apply);