1 files changed, 163 insertions, 0 deletions
diff --git a/lib/pcap.c b/lib/pcap.c
new file mode 100644
index 000000000..b2cca7611
--- /dev/null
+++ b/lib/pcap.c
@@ -0,0 +1,163 @@
+/*
+ * Copyright (c) 2009 Nicira Networks.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <config.h>
+#include "pcap.h"
+#include <assert.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <string.h>
+#include "compiler.h"
+#include "ofpbuf.h"
+
+#define THIS_MODULE VLM_pcap
+#include "vlog.h"
+
+struct pcap_hdr {
+    uint32_t magic_number;   /* magic number */
+    uint16_t version_major;  /* major version number */
+    uint16_t version_minor;  /* minor version number */
+    int32_t thiszone;        /* GMT to local correction */
+    uint32_t sigfigs;        /* accuracy of timestamps */
+    uint32_t snaplen;        /* max length of captured packets */
+    uint32_t network;        /* data link type */
+} PACKED;
+
+struct pcaprec_hdr {
+    uint32_t ts_sec;         /* timestamp seconds */
+    uint32_t ts_usec;        /* timestamp microseconds */
+    uint32_t incl_len;       /* number of octets of packet saved in file */
+    uint32_t orig_len;       /* actual length of packet */
+} PACKED;
+
+FILE *
+pcap_open(const char *file_name, const char *mode)
+{
+    FILE *file;
+
+    assert(!strcmp(mode, "rb") || !strcmp(mode, "wb"));
+
+    file = fopen(file_name, mode);
+    if (file == NULL) {
+        VLOG_WARN("%s: failed to open pcap file for %s",
+                  file_name, mode[0] == 'r' ? "reading" : "writing");
+        return NULL;
+    }
+
+    if (mode[0] == 'r') {
+        if (!pcap_read_header(file)) {
+            fclose(file);
+            return NULL;
+        }
+    } else {
+        pcap_write_header(file);
+    }
+    return file;
+}
+
+int
+pcap_read_header(FILE *file)
+{
+    struct pcap_hdr ph;
+    if (fread(&ph, sizeof ph, 1, file) != 1) {
+        int error = ferror(file) ? errno : EOF;
+        VLOG_WARN("failed to read pcap header: %s",
+                  error > 0 ? strerror(error) : "end of file");
+        return error;
+    }
+    if (ph.magic_number != 0xa1b2c3d4 && ph.magic_number != 0xd4c3b2a1) {
+        VLOG_WARN("bad magic 0x%08"PRIx32" reading pcap file "
+                  "(expected 0xa1b2c3d4 or 0xd4c3b2a1)", ph.magic_number);
+        return EPROTO;
+    }
+    return 0;
+}
+
+void
+pcap_write_header(FILE *file)
+{
+    /* The pcap reader is responsible for figuring out endianness based on the
+     * magic number, so the lack of htonX calls here is intentional. */
+    struct pcap_hdr ph;
+    ph.magic_number = 0xa1b2c3d4;
+    ph.version_major = 2;
+    ph.version_minor = 4;
+    ph.thiszone = 0;
+    ph.sigfigs = 0;
+    ph.snaplen = 1518;
+    ph.network = 1;             /* Ethernet */
+    fwrite(&ph, sizeof ph, 1, file);
+}
+
+int
+pcap_read(FILE *file, struct ofpbuf **bufp)
+{
+    struct pcaprec_hdr prh;
+    struct ofpbuf *buf;
+    void *data;
+    size_t len;
+
+    *bufp = NULL;
+
+    /* Read header. */
+    if (fread(&prh, sizeof prh, 1, file) != 1) {
+        int error = ferror(file) ? errno : EOF;
+        VLOG_WARN("failed to read pcap record header: %s",
+                  error > 0 ? strerror(error) : "end of file");
+        return error;
+    }
+
+    /* Calculate length. */
+    len = prh.incl_len;
+    if (len > 0xffff) {
+        uint32_t swapped_len = (((len & 0xff000000) >> 24) |
+                                ((len & 0x00ff0000) >>  8) |
+                                ((len & 0x0000ff00) <<  8) |
+                                ((len & 0x000000ff) << 24));
+        if (swapped_len > 0xffff) {
+            VLOG_WARN("bad packet length %"PRIu32" or %"PRIu32" "
+                      "reading pcap file",
+                      len, swapped_len);
+            return EPROTO;
+        }
+        len = swapped_len;
+    }
+
+    /* Read packet. */
+    buf = ofpbuf_new(len);
+    data = ofpbuf_put_uninit(buf, len);
+    if (fread(data, len, 1, file) != 1) {
+        int error = ferror(file) ? errno : EOF;
+        VLOG_WARN("failed to read pcap packet: %s",
+                  error > 0 ? strerror(error) : "end of file");
+        ofpbuf_delete(buf);
+        return error;
+    }
+    *bufp = buf;
+    return 0;
+}
+
+void
+pcap_write(FILE *file, struct ofpbuf *buf)
+{
+    struct pcaprec_hdr prh;
+    prh.ts_sec = 0;
+    prh.ts_usec = 0;
+    prh.incl_len = buf->size;
+    prh.orig_len = buf->size;
+    fwrite(&prh, sizeof prh, 1, file);
+    fwrite(buf->data, buf->size, 1, file);
+}