From bb0363a1a281f5863da7588148b9d6291cc55b4a Mon Sep 17 00:00:00 2001
From: XANTRONIX Development <dev@xantronix.com>
Date: Thu, 24 Jan 2019 01:55:31 -0600
Subject: [PATCH] My girl would be so proud of me

---
 examples/pcapread.c | 111 +++++++++++++++++++++++++++++++-------------
 1 file changed, 80 insertions(+), 31 deletions(-)

diff --git a/examples/pcapread.c b/examples/pcapread.c
index 468695f..7bcb84c 100644
--- a/examples/pcapread.c
+++ b/examples/pcapread.c
@@ -23,10 +23,10 @@ static void usage(int argc, char **argv, const char *message, ...) {
     exit(1);
 }
 
-static ssize_t handle_options(hexagram_pcapng_stream *stream,
-                              uint32_t type,
-                              uint16_t code,
-                              uint16_t len) {
+static ssize_t handle_option(hexagram_pcapng_stream *stream,
+                             uint32_t type,
+                             uint16_t code,
+                             uint16_t len) {
     ssize_t readlen;
     uint8_t data[65535];
 
@@ -50,40 +50,59 @@ error_io:
     return -1;
 }
 
-static ssize_t handle_block(hexagram_pcapng_stream *stream,
-                            uint32_t type,
-                            size_t len) {
-    hexagram_pcapng_packet header;
-    uint8_t body[65535];
+static ssize_t handle_block_if(hexagram_pcapng_stream *stream,
+                               uint32_t type,
+                               size_t len) {
+    hexagram_pcapng_if iface;
+
+    ssize_t readlen,
+            total = 0;
 
     size_t remaining = len;
 
-    ssize_t total = 0,
-            readlen;
-
     /*
-     * If we've received anything other than a packet block, then seek past
-     * that data and move on.
+     * Read the interface block header.
      */
-    if (type != HEXAGRAM_PCAPNG_BLOCK_PACKET) {
-        printf("Read block type %08"PRIx32" len %zu\n",
-            type, len);
+    if ((readlen = read(stream->fd, &iface, sizeof(iface))) < 0) {
+        stream->error = HEXAGRAM_PCAPNG_ERROR_IO;
 
-        if ((readlen = lseek(stream->fd, len, SEEK_CUR)) < 0) {
-            perror("lseek()");
-
-            goto error_io;
-        }
-
-        return readlen;
+        goto error_io;
+    } else {
+        remaining -= readlen;
+        total     += readlen;
     }
 
+    if ((readlen = hexagram_pcapng_read_options(stream, handle_option, type, remaining)) < 0) {
+        stream->error = HEXAGRAM_PCAPNG_ERROR_IO;
+
+        goto error_io;
+    } else {
+        total += readlen;
+    }
+
+    return total;
+
+error_io:
+    return -1;
+}
+
+static ssize_t handle_block_packet(hexagram_pcapng_stream *stream,
+                                   uint32_t type,
+                                   size_t len) {
+    hexagram_pcapng_packet header;
+    uint8_t body[65535];
+
+    ssize_t readlen,
+            total = 0;
+
+    size_t remaining = len;
+
     /*
-     * Otherwise, read the packet block header so that we may determine the
-     * size of the payload to continue to read.
+     * Read the packet block header so that we may determine the size of the
+     * payload to continue to read.
      */
     if ((readlen = read(stream->fd, &header, sizeof(header))) < 0) {
-        perror("read()");
+        stream->error = HEXAGRAM_PCAPNG_ERROR_IO;
 
         goto error_io;
     } else {
@@ -95,7 +114,7 @@ static ssize_t handle_block(hexagram_pcapng_stream *stream,
      * Read the packet body into our scratchpad.
      */
     if ((readlen = read(stream->fd, &body, header.caplen)) < 0) {
-        perror("read()");
+        stream->error = HEXAGRAM_PCAPNG_ERROR_IO;
 
         goto error_io;
     } else {
@@ -110,7 +129,7 @@ static ssize_t handle_block(hexagram_pcapng_stream *stream,
         size_t padding = sizeof(uint32_t) - (header.caplen % sizeof(uint32_t));
 
         if (lseek(stream->fd, padding, SEEK_CUR) < 0) {
-            perror("lseek()");
+            stream->error = HEXAGRAM_PCAPNG_ERROR_IO;
 
             goto error_io;
         } else {
@@ -123,10 +142,12 @@ static ssize_t handle_block(hexagram_pcapng_stream *stream,
      * The remaining data here should be pcapng option values, and since we do
      * not presently require them, we can safely seek past them.
      */
-    if ((readlen = hexagram_pcapng_read_options(stream, handle_options, type, remaining)) < 0) {
+    if (lseek(stream->fd, remaining, SEEK_CUR) < 0) {
+        stream->error = HEXAGRAM_PCAPNG_ERROR_IO;
+
         goto error_io;
     } else {
-        total += readlen;
+        total += remaining;
     }
 
     stream->error = HEXAGRAM_PCAPNG_ERROR_OK;
@@ -139,6 +160,34 @@ error_io:
     return -1;
 }
 
+static ssize_t handle_block(hexagram_pcapng_stream *stream,
+                            uint32_t type,
+                            size_t len) {
+    switch (type) {
+        case HEXAGRAM_PCAPNG_BLOCK_IF:
+            return handle_block_if(stream, type, len);
+
+        case HEXAGRAM_PCAPNG_BLOCK_PACKET:
+            return handle_block_packet(stream, type, len);
+
+        default: break;
+    }
+
+    printf("Read block type %08"PRIx32" len %zu\n",
+        type, len);
+
+    if (lseek(stream->fd, len, SEEK_CUR) < 0) {
+        stream->error = HEXAGRAM_PCAPNG_ERROR_IO;
+
+        goto error_io;
+    }
+
+    return len;
+
+error_io:
+    return -1;
+}
+
 int main(int argc, char **argv) {
     int fd;
     hexagram_pcapng_stream *stream;