summaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
authorIan Moffett <ian@osmora.org>2025-09-24 20:58:52 -0400
committerIan Moffett <ian@osmora.org>2025-09-24 20:58:52 -0400
commit570dc38023cac588a66118e8beb8dba66a3ec459 (patch)
treee330acd2f1dc7105523467c362f36b6d6806c612 /src
parente42e9220a91da7f83b4754be690a67a5ef65eed0 (diff)
dgram: Add datagram layer
Signed-off-by: Ian Moffett <ian@osmora.org>
Diffstat (limited to 'src')
-rw-r--r--src/dgram/dgram_subr.c49
-rw-r--r--src/include/dgram.h87
-rw-r--r--src/main.c13
3 files changed, 145 insertions, 4 deletions
diff --git a/src/dgram/dgram_subr.c b/src/dgram/dgram_subr.c
new file mode 100644
index 0000000..d79386f
--- /dev/null
+++ b/src/dgram/dgram_subr.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/errno.h>
+#include <stdint.h>
+#include <string.h>
+#include "dgram.h"
+#include "crc.h"
+
+int
+dgram_load(uint16_t length, uint8_t port, struct onet_dgram *res)
+{
+ if (res == NULL) {
+ return -EINVAL;
+ }
+
+ memset(res, 0, sizeof(*res));
+ res->length = (length >> 8) & 0xFF;
+ res->length |= (length & 0xFF) << 8;
+ res->port = port;
+ res->crc32 = crc32(res, sizeof(*res));
+ return 0;
+}
diff --git a/src/include/dgram.h b/src/include/dgram.h
new file mode 100644
index 0000000..93b20e3
--- /dev/null
+++ b/src/include/dgram.h
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef DGRAM_H
+#define DGRAM_H
+
+#include <stdint.h>
+#include "if_ether.h"
+
+/*
+ * Represents an ONET datagram
+ *
+ * @crc32: CRC32 checksum of data + header
+ * @length: Packet length in bytes
+ * @reserved: Reserved for future use
+ * @reserved1: Reserved for future use
+ * @port: Datagram port number to send on
+ */
+struct onet_dgram {
+ uint32_t crc32;
+ uint16_t length;
+ uint16_t reserved;
+ uint16_t reserved1;
+ uint8_t port;
+} __attribute__((packed));
+
+/*
+ * Get the total length of a datagram including
+ * the length of the ethernet header and the header
+ * of the datagram itself.
+ */
+#define DGRAM_LEN(len) \
+ (sizeof(struct onet_dgram) + sizeof(struct ether_hdr) + len)
+
+/*
+ * Get the start of the datagram header start by passing
+ * a pointer to the buffer that holds the entire packet
+ */
+#define DGRAM_HDR(packet_p) \
+ ((void *)((char *)packet_p + sizeof(struct ether_hdr)))
+
+/*
+ * Get the start of the datagram data start by passing
+ * a pointer to the buffer that holds the entire packet
+ */
+#define DGRAM_DATA(packet_p) \
+ ((char *)packet_p + sizeof(struct onet_dgram) + sizeof(struct ether_hdr))
+
+/*
+ * Initialize an ONET datagram
+ *
+ * @length: Length of a packet to send
+ * @port: Port number to send on
+ * @res: Result is written here
+ *
+ * Returns zero on success, otherwise a less than zero
+ * value on failure.
+ */
+int dgram_load(uint16_t length, uint8_t port, struct onet_dgram *res);
+
+#endif /* DGRAM_H */
diff --git a/src/main.c b/src/main.c
index 4616d12..62bf519 100644
--- a/src/main.c
+++ b/src/main.c
@@ -38,6 +38,7 @@
#include <unistd.h>
#include <string.h>
#include "if_ether.h"
+#include "dgram.h"
#define TEST_STR "Hello from o.1p!! Meow meow!"
@@ -57,15 +58,18 @@ help(char **argv)
static int
data_send(void)
{
- char data[256], *p;
+ char data[DGRAM_LEN(128)], *p;
struct sockaddr_ll saddr;
struct ether_hdr *eth;
+ struct onet_dgram *dgram;
struct ifreq ifr;
int error, sockfd;
- memset(data, 0, sizeof(data));
eth = (struct ether_hdr *)data;
- p = &data[sizeof(eth) + 100];
+ p = DGRAM_DATA(data);
+ dgram = DGRAM_HDR(data);
+
+ memset(data, 0, sizeof(data));
memcpy(p, TEST_STR, sizeof(TEST_STR));
sockfd = socket(AF_PACKET, SOCK_RAW, IPPROTO_RAW);
@@ -83,12 +87,13 @@ data_send(void)
}
/*
- * Set up link layer sockaddr, load up the frame
+ * Set up link layer sockaddr, load up the frame, datagram
* and send it off.
*/
saddr.sll_ifindex = ifr.ifr_ifindex;
saddr.sll_halen = ETH_ALEN;
ether_load_route(0x54E1AD2CAE48, 0xFFFFFFFFFFFF, eth);
+ dgram_load(sizeof(TEST_STR), 50, dgram);
sendto(
sockfd, &data, sizeof(data), 0,
(struct sockaddr *)&saddr, sizeof(struct sockaddr_ll)