[PATCH net-next v3 11/11] net: Add samples for network I/O and splicing
From: David Howells
Date: Fri Jun 02 2023 - 11:10:21 EST
Add some small sample programs for doing network I/O including splicing.
There are three IPv4/IPv6 servers: tcp-sink, tls-sink and udp-sink. They
can be given a port number by passing "-p <port>" and will listen on an
IPv6 socket unless given a "-4" flag, in which case they'll listen for IPv4
only.
There are three IPv4/IPv6 clients: tcp-send, tls-send and udp-send. They
are given a file to get data from (or "-" for stdin) and the name of a
server to talk to. They can also be given a port number by passing "-p
<port>", "-4" or "-6" to force the use of IPv4 or IPv6, "-s" to indicate
they should use splice/sendfile to transfer the data and "-n" to specify
how much data to copy. If "-s" is given, the input will be spliced if it's
a pipe and sendfiled otherwise.
A driver program, splice-out, is provided to splice data from a file/stdin
to stdout and can be used to pipe into the aforementioned clients for
testing splice. This takes the name of the file to splice from (or "-" for
stdin). It can also be given "-w <size>" to indicate the maximum size of
each splice, "-k <size>" if a chunk of the input should be skipped between
splices to prevent coalescence and "-s" if sendfile should be used instead
of splice.
Additionally, there is an AF_UNIX client and server. These are similar to
the IPv[46] programs, except both take a socket path and there is no option
to change the port number.
And then there are two AF_ALG clients (there is no server). These are
similar to the other clients, except no destination is specified. One
exercised skcipher encryption and the other hashing.
Examples include:
./splice-out -w0x400 /foo/16K 4K | ./alg-encrypt -s -
./splice-out -w0x400 /foo/1M | ./unix-send -s - /tmp/foo
./splice-out -w0x400 /foo/16K 16K -w1 | ./tls-send -s6 -n16K - servbox
./tcp-send /bin/ls 192.168.6.1
./udp-send -4 -p5555 /foo/4K localhost
where, for example, /foo/16K is a 16KiB file.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Willem de Bruijn <willemdebruijn.kernel@xxxxxxxxx>
cc: Boris Pismenny <borisp@xxxxxxxxxx>
cc: John Fastabend <john.fastabend@xxxxxxxxx>
cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
cc: Eric Dumazet <edumazet@xxxxxxxxxx>
cc: Jakub Kicinski <kuba@xxxxxxxxxx>
cc: Paolo Abeni <pabeni@xxxxxxxxxx>
cc: Jens Axboe <axboe@xxxxxxxxx>
cc: netdev@xxxxxxxxxxxxxxx
---
samples/Kconfig | 14 +++
samples/Makefile | 1 +
samples/net/Makefile | 13 +++
samples/net/alg-encrypt.c | 206 ++++++++++++++++++++++++++++++++++++++
samples/net/alg-hash.c | 147 +++++++++++++++++++++++++++
samples/net/splice-out.c | 147 +++++++++++++++++++++++++++
samples/net/tcp-send.c | 177 ++++++++++++++++++++++++++++++++
samples/net/tcp-sink.c | 80 +++++++++++++++
samples/net/tls-send.c | 188 ++++++++++++++++++++++++++++++++++
samples/net/tls-sink.c | 104 +++++++++++++++++++
samples/net/udp-send.c | 156 +++++++++++++++++++++++++++++
samples/net/udp-sink.c | 84 ++++++++++++++++
samples/net/unix-send.c | 151 ++++++++++++++++++++++++++++
samples/net/unix-sink.c | 54 ++++++++++
14 files changed, 1522 insertions(+)
create mode 100644 samples/net/Makefile
create mode 100644 samples/net/alg-encrypt.c
create mode 100644 samples/net/alg-hash.c
create mode 100644 samples/net/splice-out.c
create mode 100644 samples/net/tcp-send.c
create mode 100644 samples/net/tcp-sink.c
create mode 100644 samples/net/tls-send.c
create mode 100644 samples/net/tls-sink.c
create mode 100644 samples/net/udp-send.c
create mode 100644 samples/net/udp-sink.c
create mode 100644 samples/net/unix-send.c
create mode 100644 samples/net/unix-sink.c
diff --git a/samples/Kconfig b/samples/Kconfig
index b2db430bd3ff..928e06b08b99 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -280,6 +280,20 @@ config SAMPLE_KMEMLEAK
Build a sample program which have explicitly leaks memory to test
kmemleak
+config SAMPLE_NET
+ bool "Build example programs for driving network protocols"
+ depends on NET
+ help
+ Build example userspace programs for driving network protocols. Most
+ of the programs (tcp, udp, tls, unix) come as client-server pairs
+ that allow the test to be split across a network (but not in the unix
+ case); but some, such as the AF_ALG samples are standalone as there
+ is no server per se.
+
+ The programs allow sendfile and splice to be used. An additional
+ program is provided that allows sendfile/splice to stdout for use in
+ piping in to the other programs to operate splice there.
+
source "samples/rust/Kconfig"
endif # SAMPLES
diff --git a/samples/Makefile b/samples/Makefile
index 7727f1a0d6d1..b9fbf80a53be 100644
--- a/samples/Makefile
+++ b/samples/Makefile
@@ -37,3 +37,4 @@ obj-$(CONFIG_SAMPLE_KMEMLEAK) += kmemleak/
obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG) += coresight/
obj-$(CONFIG_SAMPLE_FPROBE) += fprobe/
obj-$(CONFIG_SAMPLES_RUST) += rust/
+obj-$(CONFIG_SAMPLE_NET) += net/
diff --git a/samples/net/Makefile b/samples/net/Makefile
new file mode 100644
index 000000000000..0ccd68a36edf
--- /dev/null
+++ b/samples/net/Makefile
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0-only
+userprogs-always-y += \
+ alg-hash \
+ alg-encrypt \
+ splice-out \
+ tcp-send \
+ tcp-sink \
+ tls-send \
+ tls-sink \
+ udp-send \
+ udp-sink \
+ unix-send \
+ unix-sink
diff --git a/samples/net/alg-encrypt.c b/samples/net/alg-encrypt.c
new file mode 100644
index 000000000000..3851b5fbaeda
--- /dev/null
+++ b/samples/net/alg-encrypt.c
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* AF_ALG hash test
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <getopt.h>
+#include <limits.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/un.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/sendfile.h>
+#include <linux/if_alg.h>
+
+#define OSERROR(X, Y) \
+ do { if ((long)(X) == -1) { perror(Y); exit(1); } } while (0)
+#define min(x, y) ((x) < (y) ? (x) : (y))
+
+static unsigned char buffer[4096 * 32] __attribute__((aligned(4096)));
+static unsigned char iv[16];
+static unsigned char key[16];
+
+static const struct sockaddr_alg sa = {
+ .salg_family = AF_ALG,
+ .salg_type = "skcipher",
+ .salg_name = "cbc(aes)",
+};
+
+static void format(void)
+{
+ fprintf(stderr, "alg-send [-ds] [-n<size>] <file>|-\n");
+ exit(2);
+}
+
+static void algif_add_set_op(struct msghdr *msg, unsigned int op)
+{
+ struct cmsghdr *__cmsg;
+
+ __cmsg = msg->msg_control + msg->msg_controllen;
+ __cmsg->cmsg_len = CMSG_LEN(sizeof(unsigned int));
+ __cmsg->cmsg_level = SOL_ALG;
+ __cmsg->cmsg_type = ALG_SET_OP;
+ *(unsigned int *)CMSG_DATA(__cmsg) = op;
+ msg->msg_controllen += CMSG_ALIGN(__cmsg->cmsg_len);
+}
+
+static void algif_add_set_iv(struct msghdr *msg, const void *iv, size_t ivlen)
+{
+ struct af_alg_iv *ivbuf;
+ struct cmsghdr *__cmsg;
+
+ printf("%zx\n", msg->msg_controllen);
+ __cmsg = msg->msg_control + msg->msg_controllen;
+ __cmsg->cmsg_len = CMSG_LEN(sizeof(*ivbuf) + ivlen);
+ __cmsg->cmsg_level = SOL_ALG;
+ __cmsg->cmsg_type = ALG_SET_IV;
+ ivbuf = (struct af_alg_iv *)CMSG_DATA(__cmsg);
+ ivbuf->ivlen = ivlen;
+ memcpy(ivbuf->iv, iv, ivlen);
+ msg->msg_controllen += CMSG_ALIGN(__cmsg->cmsg_len);
+}
+
+int main(int argc, char *argv[])
+{
+ struct msghdr msg;
+ struct stat st;
+ const char *filename;
+ unsigned char ctrl[4096];
+ unsigned int flags = O_RDONLY;
+ ssize_t r, w, o, ret;
+ size_t size = LONG_MAX, total = 0, i, out = 160;
+ char *end;
+ bool use_sendfile = false, all = true;
+ int opt, alg, sock, fd = 0;
+
+ while ((opt = getopt(argc, argv, "dn:s")) != EOF) {
+ switch (opt) {
+ case 'd':
+ flags |= O_DIRECT;
+ break;
+ case 'n':
+ size = strtoul(optarg, &end, 0);
+ switch (*end) {
+ case 'K':
+ case 'k':
+ size *= 1024;
+ break;
+ case 'M':
+ case 'm':
+ size *= 1024 * 1024;
+ break;
+ }
+ all = false;
+ break;
+ case 's':
+ use_sendfile = true;
+ break;
+ default:
+ format();
+ }
+ }
+
+ argc -= optind;
+ argv += optind;
+ if (argc != 1)
+ format();
+ filename = argv[0];
+
+ alg = socket(AF_ALG, SOCK_SEQPACKET, 0);
+ OSERROR(alg, "AF_ALG");
+ OSERROR(bind(alg, (struct sockaddr *)&sa, sizeof(sa)), "bind");
+ OSERROR(setsockopt(alg, SOL_ALG, ALG_SET_KEY, key, sizeof(key)),
+ "ALG_SET_KEY");
+ sock = accept(alg, NULL, 0);
+ OSERROR(sock, "accept");
+
+ if (strcmp(filename, "-") != 0) {
+ fd = open(filename, flags);
+ OSERROR(fd, filename);
+ OSERROR(fstat(fd, &st), filename);
+ size = st.st_size;
+ } else {
+ OSERROR(fstat(fd, &st), argv[2]);
+ }
+
+ memset(&msg, 0, sizeof(msg));
+ msg.msg_control = ctrl;
+ algif_add_set_op(&msg, ALG_OP_ENCRYPT);
+ algif_add_set_iv(&msg, iv, sizeof(iv));
+
+ OSERROR(sendmsg(sock, &msg, MSG_MORE), "sock/sendmsg");
+
+ if (!use_sendfile) {
+ bool more = false;
+
+ while (size) {
+ r = read(fd, buffer, sizeof(buffer));
+ OSERROR(r, filename);
+ if (r == 0)
+ break;
+ size -= r;
+
+ o = 0;
+ do {
+ more = size > 0;
+ w = send(sock, buffer + o, r - o,
+ more ? MSG_MORE : 0);
+ OSERROR(w, "sock/send");
+ total += w;
+ o += w;
+ } while (o < r);
+ }
+
+ if (more)
+ send(sock, NULL, 0, 0);
+ } else if (S_ISFIFO(st.st_mode)) {
+ do {
+ r = splice(fd, NULL, sock, NULL, size,
+ size > 0 ? SPLICE_F_MORE : 0);
+ OSERROR(r, "sock/splice");
+ size -= r;
+ total += r;
+ } while (r > 0 && size > 0);
+ if (size && !all) {
+ fprintf(stderr, "Short splice\n");
+ exit(1);
+ }
+ } else {
+ r = sendfile(sock, fd, NULL, size);
+ OSERROR(r, "sock/sendfile");
+ if (r != size) {
+ fprintf(stderr, "Short sendfile\n");
+ exit(1);
+ }
+ total = r;
+ }
+
+ while (total > 0) {
+ ret = read(sock, buffer, min(sizeof(buffer), total));
+ OSERROR(ret, "sock/read");
+ if (ret == 0)
+ break;
+ total -= ret;
+
+ if (out > 0) {
+ ret = min(out, ret);
+ out -= ret;
+ for (i = 0; i < ret; i++)
+ printf("%02x", (unsigned char)buffer[i]);
+ }
+ printf("...\n");
+ }
+
+ OSERROR(close(sock), "sock/close");
+ OSERROR(close(alg), "alg/close");
+ OSERROR(close(fd), "close");
+ return 0;
+}
diff --git a/samples/net/alg-hash.c b/samples/net/alg-hash.c
new file mode 100644
index 000000000000..df63c87e7661
--- /dev/null
+++ b/samples/net/alg-hash.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* AF_ALG hash test
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <getopt.h>
+#include <limits.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/un.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/sendfile.h>
+#include <linux/if_alg.h>
+
+#define OSERROR(X, Y) \
+ do { if ((long)(X) == -1) { perror(Y); exit(1); } } while (0)
+
+static unsigned char buffer[4096 * 32] __attribute__((aligned(4096)));
+
+static const struct sockaddr_alg sa = {
+ .salg_family = AF_ALG,
+ .salg_type = "hash",
+ .salg_name = "sha1",
+};
+
+static void format(void)
+{
+ fprintf(stderr, "alg-send [-ds] [-n<size>] <file>|-\n");
+ exit(2);
+}
+
+int main(int argc, char *argv[])
+{
+ struct stat st;
+ const char *filename;
+ unsigned int flags = O_RDONLY;
+ ssize_t r, w, o, ret;
+ size_t size = LONG_MAX, i;
+ char *end;
+ int use_sendfile = 0;
+ int opt, alg, sock, fd = 0;
+
+ while ((opt = getopt(argc, argv, "n:s")) != EOF) {
+ switch (opt) {
+ case 'd':
+ flags |= O_DIRECT;
+ break;
+ case 'n':
+ size = strtoul(optarg, &end, 0);
+ switch (*end) {
+ case 'K':
+ case 'k':
+ size *= 1024;
+ break;
+ case 'M':
+ case 'm':
+ size *= 1024 * 1024;
+ break;
+ }
+ break;
+ case 's':
+ use_sendfile = true;
+ break;
+ default:
+ format();
+ }
+ }
+
+ argc -= optind;
+ argv += optind;
+ if (argc != 1)
+ format();
+ filename = argv[0];
+
+ alg = socket(AF_ALG, SOCK_SEQPACKET, 0);
+ OSERROR(alg, "AF_ALG");
+ OSERROR(bind(alg, (struct sockaddr *)&sa, sizeof(sa)), "bind");
+ sock = accept(alg, NULL, 0);
+ OSERROR(sock, "accept");
+
+ if (strcmp(filename, "-") != 0) {
+ fd = open(filename, flags);
+ OSERROR(fd, filename);
+ OSERROR(fstat(fd, &st), filename);
+ size = st.st_size;
+ } else {
+ OSERROR(fstat(fd, &st), argv[2]);
+ }
+
+ if (!use_sendfile) {
+ bool more = false;
+
+ while (size) {
+ r = read(fd, buffer, sizeof(buffer));
+ OSERROR(r, filename);
+ if (r == 0)
+ break;
+ size -= r;
+
+ o = 0;
+ do {
+ more = size > 0;
+ w = send(sock, buffer + o, r - o,
+ more ? MSG_MORE : 0);
+ OSERROR(w, "sock/send");
+ o += w;
+ } while (o < r);
+ }
+
+ if (more)
+ send(sock, NULL, 0, 0);
+ } else if (S_ISFIFO(st.st_mode)) {
+ r = splice(fd, NULL, sock, NULL, size, 0);
+ OSERROR(r, "sock/splice");
+ if (r != size) {
+ fprintf(stderr, "Short splice\n");
+ exit(1);
+ }
+ } else {
+ r = sendfile(sock, fd, NULL, size);
+ OSERROR(r, "sock/sendfile");
+ if (r != size) {
+ fprintf(stderr, "Short sendfile\n");
+ exit(1);
+ }
+ }
+
+ ret = read(sock, buffer, sizeof(buffer));
+ OSERROR(ret, "sock/read");
+
+ for (i = 0; i < ret; i++)
+ printf("%02x", (unsigned char)buffer[i]);
+ printf("\n");
+
+ OSERROR(close(sock), "sock/close");
+ OSERROR(close(alg), "alg/close");
+ OSERROR(close(fd), "close");
+ return 0;
+}
diff --git a/samples/net/splice-out.c b/samples/net/splice-out.c
new file mode 100644
index 000000000000..224010dfd387
--- /dev/null
+++ b/samples/net/splice-out.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Splice or sendfile from the given file/stdin to stdout.
+ *
+ * Format: splice-out [-s] <file>|- [<size>]
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <sys/stat.h>
+#include <sys/sendfile.h>
+
+#define OSERROR(X, Y) \
+ do { if ((long)(X) == -1) { perror(Y); exit(1); } } while (0)
+#define min(x, y) ((x) < (y) ? (x) : (y))
+
+static unsigned char buffer[4096];
+
+static void format(void)
+{
+ fprintf(stderr, "splice-out [-dkN][-s][-wN] <file>|- [<size>]\n");
+ exit(2);
+}
+
+int main(int argc, char *argv[])
+{
+ struct stat st;
+ const char *filename;
+ unsigned int flags = O_RDONLY;
+ ssize_t r;
+ size_t size = 1024 * 1024, skip = 0, unit = 0, part;
+ char *end;
+ bool use_sendfile = false, all = true;
+ int opt, fd = 0;
+
+ while ((opt = getopt(argc, argv, "dk:sw:")),
+ opt != -1) {
+ switch (opt) {
+ case 'd':
+ flags |= O_DIRECT;
+ break;
+ case 'k':
+ /* Skip size - prevent coalescence. */
+ skip = strtoul(optarg, &end, 0);
+ if (skip < 1 || skip >= 4096) {
+ fprintf(stderr, "-kN must be 0<N<4096\n");
+ exit(2);
+ }
+ break;
+ case 's':
+ use_sendfile = 1;
+ break;
+ case 'w':
+ /* Write unit size */
+ unit = strtoul(optarg, &end, 0);
+ if (!unit) {
+ fprintf(stderr, "-wN must be >0\n");
+ exit(2);
+ }
+ switch (*end) {
+ case 'K':
+ case 'k':
+ unit *= 1024;
+ break;
+ case 'M':
+ case 'm':
+ unit *= 1024 * 1024;
+ break;
+ }
+ break;
+ default:
+ format();
+ }
+ }
+
+ argc -= optind;
+ argv += optind;
+
+ if (argc != 1 && argc != 2)
+ format();
+
+ filename = argv[0];
+ if (argc == 2) {
+ size = strtoul(argv[1], &end, 0);
+ switch (*end) {
+ case 'K':
+ case 'k':
+ size *= 1024;
+ break;
+ case 'M':
+ case 'm':
+ size *= 1024 * 1024;
+ break;
+ }
+ all = false;
+ }
+
+ OSERROR(fstat(1, &st), "stdout");
+ if (!S_ISFIFO(st.st_mode)) {
+ fprintf(stderr, "stdout must be a pipe\n");
+ exit(3);
+ }
+
+ if (strcmp(filename, "-") != 0) {
+ fd = open(filename, flags);
+ OSERROR(fd, filename);
+ OSERROR(fstat(fd, &st), filename);
+ if (!all && size > st.st_size) {
+ fprintf(stderr, "%s: Specified size larger than file\n",
+ filename);
+ exit(3);
+ }
+ }
+
+ do {
+ if (skip) {
+ part = skip;
+ do {
+ r = read(fd, buffer, skip);
+ OSERROR(r, filename);
+ part -= r;
+ } while (part > 0 && r > 0);
+ }
+
+ part = unit ? min(size, unit) : size;
+ if (use_sendfile) {
+ r = sendfile(1, fd, NULL, part);
+ OSERROR(r, "sendfile");
+ } else {
+ r = splice(fd, NULL, 1, NULL, part, 0);
+ OSERROR(r, "splice");
+ }
+ if (!all)
+ size -= r;
+ } while (r > 0 && size > 0);
+
+ OSERROR(close(fd), "close");
+ return 0;
+}
diff --git a/samples/net/tcp-send.c b/samples/net/tcp-send.c
new file mode 100644
index 000000000000..608055354789
--- /dev/null
+++ b/samples/net/tcp-send.c
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TCP send client. Pass -s to use splice/sendfile; -z to use MSG_ZEROCOPY.
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <getopt.h>
+#include <limits.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <sys/stat.h>
+#include <sys/sendfile.h>
+
+#define OSERROR(X, Y) \
+ do { if ((long)(X) == -1) { perror(Y); exit(1); } } while (0)
+
+static unsigned char buffer[4096] __attribute__((aligned(4096)));
+
+static void format(void)
+{
+ fprintf(stderr,
+ "tcp-send [-46dsz][-p<port>][-n<size>] <file>|- <server>\n");
+ exit(2);
+}
+
+int main(int argc, char *argv[])
+{
+ struct addrinfo *addrs = NULL, hints = {};
+ struct stat st;
+ const char *filename, *sockname, *service = "5555";
+ unsigned int flags = O_RDONLY;
+ ssize_t r, w, o;
+ size_t size = LONG_MAX;
+ char *end;
+ bool use_sendfile = false, use_zerocopy = false, all = true;
+ int opt, sock, fd = 0, gai;
+
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_socktype = SOCK_STREAM;
+
+ while ((opt = getopt(argc, argv, "46dn:p:sz")) != EOF) {
+ switch (opt) {
+ case '4':
+ hints.ai_family = AF_INET;
+ break;
+ case '6':
+ hints.ai_family = AF_INET6;
+ break;
+ case 'd':
+ flags |= O_DIRECT;
+ break;
+ case 'n':
+ size = strtoul(optarg, &end, 0);
+ switch (*end) {
+ case 'K':
+ case 'k':
+ size *= 1024;
+ break;
+ case 'M':
+ case 'm':
+ size *= 1024 * 1024;
+ break;
+ }
+ all = false;
+ break;
+ case 'p':
+ service = optarg;
+ break;
+ case 's':
+ use_sendfile = true;
+ break;
+ case 'z':
+ use_zerocopy = true;
+ break;
+ default:
+ format();
+ }
+ }
+
+ argc -= optind;
+ argv += optind;
+ if (argc != 2)
+ format();
+ filename = argv[0];
+ sockname = argv[1];
+
+ gai = getaddrinfo(sockname, service, &hints, &addrs);
+ if (gai) {
+ fprintf(stderr, "%s: %s\n", sockname, gai_strerror(gai));
+ exit(3);
+ }
+
+ if (!addrs) {
+ fprintf(stderr, "%s: No addresses\n", sockname);
+ exit(3);
+ }
+
+ sockname = addrs->ai_canonname;
+ sock = socket(addrs->ai_family, addrs->ai_socktype, addrs->ai_protocol);
+ OSERROR(sock, "socket");
+ OSERROR(connect(sock, addrs->ai_addr, addrs->ai_addrlen), "connect");
+
+ if (strcmp(filename, "-") != 0) {
+ fd = open(filename, flags);
+ OSERROR(fd, filename);
+ OSERROR(fstat(fd, &st), filename);
+ if (size > st.st_size)
+ size = st.st_size;
+ } else {
+ OSERROR(fstat(fd, &st), filename);
+ }
+
+ if (!use_sendfile) {
+ unsigned int flags = 0;
+
+ if (use_zerocopy) {
+ int zcflag = 1;
+
+ OSERROR(setsockopt(sock, SOL_SOCKET, SO_ZEROCOPY,
+ &zcflag, sizeof(zcflag)),
+ "SOCK_ZEROCOPY");
+ flags |= MSG_ZEROCOPY;
+ }
+
+ while (size) {
+ r = read(fd, buffer, sizeof(buffer));
+ OSERROR(r, filename);
+ if (r == 0)
+ break;
+ size -= r;
+
+ o = 0;
+ do {
+ flags &= ~MSG_MORE;
+ if (size > 0)
+ flags |= MSG_MORE;
+ w = send(sock, buffer + o, r - o, flags);
+ OSERROR(w, "sock/send");
+ o += w;
+ } while (o < r);
+ }
+
+ if (flags & MSG_MORE)
+ send(sock, NULL, 0, flags & ~MSG_MORE);
+ } else if (S_ISFIFO(st.st_mode)) {
+ do {
+ r = splice(fd, NULL, sock, NULL, size,
+ size > 0 ? SPLICE_F_MORE : 0);
+ OSERROR(r, "sock/splice");
+ size -= r;
+ } while (r > 0 && size > 0);
+ if (size && !all) {
+ fprintf(stderr, "Short splice\n");
+ exit(1);
+ }
+ } else {
+ r = sendfile(sock, fd, NULL, size);
+ OSERROR(r, "sock/sendfile");
+ if (r != size) {
+ fprintf(stderr, "Short sendfile\n");
+ exit(1);
+ }
+ }
+
+ OSERROR(close(sock), "sock/close");
+ OSERROR(close(fd), "close");
+ return 0;
+}
diff --git a/samples/net/tcp-sink.c b/samples/net/tcp-sink.c
new file mode 100644
index 000000000000..5c27c24dfb76
--- /dev/null
+++ b/samples/net/tcp-sink.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TCP sink server
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <getopt.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <netinet/in.h>
+
+#define OSERROR(X, Y) \
+ do { if ((long)(X) == -1) { perror(Y); exit(1); } } while (0)
+
+static unsigned char buffer[512 * 1024];
+
+static void format(void)
+{
+ fprintf(stderr, "tcp-sink [-4][-p<port>]\n");
+ exit(2);
+}
+
+int main(int argc, char *argv[])
+{
+ unsigned int port = 5555;
+ bool ipv6 = true;
+ int opt, server_sock, sock;
+
+
+ while ((opt = getopt(argc, argv, "4p:")) != EOF) {
+ switch (opt) {
+ case '4':
+ ipv6 = false;
+ break;
+ case 'p':
+ port = atoi(optarg);
+ break;
+ default:
+ format();
+ }
+ }
+
+ if (!ipv6) {
+ struct sockaddr_in sin = {
+ .sin_family = AF_INET,
+ .sin_port = htons(port),
+ };
+ server_sock = socket(AF_INET, SOCK_STREAM, 0);
+ OSERROR(server_sock, "socket");
+ OSERROR(bind(server_sock, (struct sockaddr *)&sin, sizeof(sin)),
+ "bind");
+ OSERROR(listen(server_sock, 1), "listen");
+ } else {
+ struct sockaddr_in6 sin6 = {
+ .sin6_family = AF_INET6,
+ .sin6_port = htons(port),
+ };
+ server_sock = socket(AF_INET6, SOCK_STREAM, 0);
+ OSERROR(server_sock, "socket");
+ OSERROR(bind(server_sock, (struct sockaddr *)&sin6,
+ sizeof(sin6)),
+ "bind");
+ OSERROR(listen(server_sock, 1), "listen");
+ }
+
+ for (;;) {
+ sock = accept(server_sock, NULL, NULL);
+ if (sock != -1) {
+ while (read(sock, buffer, sizeof(buffer)) > 0)
+ ;
+ close(sock);
+ }
+ }
+}
diff --git a/samples/net/tls-send.c b/samples/net/tls-send.c
new file mode 100644
index 000000000000..d99b79aaf536
--- /dev/null
+++ b/samples/net/tls-send.c
@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TLS-over-TCP send client. Pass -s to splice.
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <getopt.h>
+#include <limits.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <sys/stat.h>
+#include <sys/sendfile.h>
+#include <linux/tls.h>
+
+#define OSERROR(X, Y) \
+ do { if ((long)(X) == -1) { perror(Y); exit(1); } } while (0)
+
+static unsigned char buffer[4096];
+
+static void format(void)
+{
+ fprintf(stderr,
+ "tls-send [-46ds][-n<size>][-p<port>] <file>|- <server>\n");
+ exit(2);
+}
+
+static void set_tls(int sock)
+{
+ struct tls12_crypto_info_aes_gcm_128 crypto_info;
+
+ crypto_info.info.version = TLS_1_2_VERSION;
+ crypto_info.info.cipher_type = TLS_CIPHER_AES_GCM_128;
+ memset(crypto_info.iv, 0, TLS_CIPHER_AES_GCM_128_IV_SIZE);
+ memset(crypto_info.rec_seq, 0, TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE);
+ memset(crypto_info.key, 0, TLS_CIPHER_AES_GCM_128_KEY_SIZE);
+ memset(crypto_info.salt, 0, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
+
+ OSERROR(setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")),
+ "TCP_ULP");
+ OSERROR(setsockopt(sock, SOL_TLS, TLS_TX, &crypto_info,
+ sizeof(crypto_info)),
+ "TLS_TX");
+ OSERROR(setsockopt(sock, SOL_TLS, TLS_RX, &crypto_info,
+ sizeof(crypto_info)),
+ "TLS_RX");
+}
+
+int main(int argc, char *argv[])
+{
+ struct addrinfo *addrs = NULL, hints = {};
+ struct stat st;
+ const char *filename, *sockname, *service = "5556";
+ unsigned int flags = O_RDONLY;
+ ssize_t r, w, o;
+ size_t size = LONG_MAX;
+ char *end;
+ bool use_sendfile = false, all = true;
+ int opt, sock, fd = 0, gai;
+
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_socktype = SOCK_STREAM;
+
+ while ((opt = getopt(argc, argv, "46dn:p:s")) != EOF) {
+ switch (opt) {
+ case '4':
+ hints.ai_family = AF_INET;
+ break;
+ case '6':
+ hints.ai_family = AF_INET6;
+ break;
+ case 'd':
+ flags |= O_DIRECT;
+ break;
+ case 'n':
+ size = strtoul(optarg, &end, 0);
+ switch (*end) {
+ case 'K':
+ case 'k':
+ size *= 1024;
+ break;
+ case 'M':
+ case 'm':
+ size *= 1024 * 1024;
+ break;
+ }
+ all = false;
+ break;
+ case 'p':
+ service = optarg;
+ break;
+ case 's':
+ use_sendfile = true;
+ break;
+ default:
+ format();
+ }
+ }
+
+ argc -= optind;
+ argv += optind;
+ if (argc != 2)
+ format();
+ filename = argv[0];
+ sockname = argv[1];
+
+ gai = getaddrinfo(sockname, service, &hints, &addrs);
+ if (gai) {
+ fprintf(stderr, "%s: %s\n", sockname, gai_strerror(gai));
+ exit(3);
+ }
+
+ if (!addrs) {
+ fprintf(stderr, "%s: No addresses\n", sockname);
+ exit(3);
+ }
+
+ sockname = addrs->ai_canonname;
+ sock = socket(addrs->ai_family, addrs->ai_socktype, addrs->ai_protocol);
+ OSERROR(sock, "socket");
+ OSERROR(connect(sock, addrs->ai_addr, addrs->ai_addrlen), "connect");
+ set_tls(sock);
+
+ if (strcmp(filename, "-") != 0) {
+ fd = open(filename, flags);
+ OSERROR(fd, filename);
+ OSERROR(fstat(fd, &st), filename);
+ if (size > st.st_size)
+ size = st.st_size;
+ } else {
+ OSERROR(fstat(fd, &st), filename);
+ }
+
+ if (!use_sendfile) {
+ bool more = false;
+
+ while (size) {
+ r = read(fd, buffer, sizeof(buffer));
+ OSERROR(r, filename);
+ if (r == 0)
+ break;
+ size -= r;
+
+ o = 0;
+ do {
+ more = size > 0;
+ w = send(sock, buffer + o, r - o,
+ more ? MSG_MORE : 0);
+ OSERROR(w, "sock/send");
+ o += w;
+ } while (o < r);
+ }
+
+ if (more)
+ send(sock, NULL, 0, 0);
+ } else if (S_ISFIFO(st.st_mode)) {
+ do {
+ r = splice(fd, NULL, sock, NULL, size,
+ size > 0 ? SPLICE_F_MORE : 0);
+ OSERROR(r, "sock/splice");
+ size -= r;
+ } while (r > 0 && size > 0);
+ if (size && !all) {
+ fprintf(stderr, "Short splice\n");
+ exit(1);
+ }
+ } else {
+ r = sendfile(sock, fd, NULL, size);
+ OSERROR(r, "sock/sendfile");
+ if (r != size) {
+ fprintf(stderr, "Short sendfile\n");
+ exit(1);
+ }
+ }
+
+ OSERROR(close(sock), "sock/close");
+ OSERROR(close(fd), "close");
+ return 0;
+}
diff --git a/samples/net/tls-sink.c b/samples/net/tls-sink.c
new file mode 100644
index 000000000000..67900b74d6d6
--- /dev/null
+++ b/samples/net/tls-sink.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TLS-over-TCP sink server
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <getopt.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <linux/tls.h>
+
+#define OSERROR(X, Y) \
+ do { if ((long)(X) == -1) { perror(Y); exit(1); } } while (0)
+
+static unsigned char buffer[512 * 1024];
+
+static void format(void)
+{
+ fprintf(stderr, "tls-sink [-4][-p<port>]\n");
+ exit(2);
+}
+
+static void set_tls(int sock)
+{
+ struct tls12_crypto_info_aes_gcm_128 crypto_info;
+
+ crypto_info.info.version = TLS_1_2_VERSION;
+ crypto_info.info.cipher_type = TLS_CIPHER_AES_GCM_128;
+ memset(crypto_info.iv, 0, TLS_CIPHER_AES_GCM_128_IV_SIZE);
+ memset(crypto_info.rec_seq, 0, TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE);
+ memset(crypto_info.key, 0, TLS_CIPHER_AES_GCM_128_KEY_SIZE);
+ memset(crypto_info.salt, 0, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
+
+ OSERROR(setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")),
+ "TCP_ULP");
+ OSERROR(setsockopt(sock, SOL_TLS, TLS_TX, &crypto_info,
+ sizeof(crypto_info)),
+ "TLS_TX");
+ OSERROR(setsockopt(sock, SOL_TLS, TLS_RX, &crypto_info,
+ sizeof(crypto_info)),
+ "TLS_RX");
+}
+
+int main(int argc, char *argv[])
+{
+ unsigned int port = 5556;
+ bool ipv6 = true;
+ int opt, server_sock, sock;
+
+
+ while ((opt = getopt(argc, argv, "4p:")) != EOF) {
+ switch (opt) {
+ case '4':
+ ipv6 = false;
+ break;
+ case 'p':
+ port = atoi(optarg);
+ break;
+ default:
+ format();
+ }
+ }
+
+ if (!ipv6) {
+ struct sockaddr_in sin = {
+ .sin_family = AF_INET,
+ .sin_port = htons(port),
+ };
+ server_sock = socket(AF_INET, SOCK_STREAM, 0);
+ OSERROR(server_sock, "socket");
+ OSERROR(bind(server_sock, (struct sockaddr *)&sin, sizeof(sin)),
+ "bind");
+ OSERROR(listen(server_sock, 1), "listen");
+ } else {
+ struct sockaddr_in6 sin6 = {
+ .sin6_family = AF_INET6,
+ .sin6_port = htons(port),
+ };
+ server_sock = socket(AF_INET6, SOCK_STREAM, 0);
+ OSERROR(server_sock, "socket");
+ OSERROR(bind(server_sock, (struct sockaddr *)&sin6,
+ sizeof(sin6)),
+ "bind");
+ OSERROR(listen(server_sock, 1), "listen");
+ }
+
+ for (;;) {
+ sock = accept(server_sock, NULL, NULL);
+ if (sock != -1) {
+ set_tls(sock);
+ while (read(sock, buffer, sizeof(buffer)) > 0)
+ ;
+ close(sock);
+ }
+ }
+}
diff --git a/samples/net/udp-send.c b/samples/net/udp-send.c
new file mode 100644
index 000000000000..7c6c27eb0fcc
--- /dev/null
+++ b/samples/net/udp-send.c
@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * UDP send client. Pass -s to splice.
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <getopt.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <sys/stat.h>
+#include <sys/sendfile.h>
+
+#define OSERROR(X, Y) \
+ do { if ((long)(X) == -1) { perror(Y); exit(1); } } while (0)
+#define min(x, y) ((x) < (y) ? (x) : (y))
+
+static unsigned char buffer[65536];
+
+static void format(void)
+{
+ fprintf(stderr,
+ "udp-send [-46s][-n<size>][-p<port>] <file>|- <server>\n");
+ exit(2);
+}
+
+int main(int argc, char *argv[])
+{
+ struct addrinfo *addrs = NULL, hints = {};
+ struct stat st;
+ const char *filename, *sockname, *service = "5555";
+ unsigned int flags = O_RDONLY, len;
+ ssize_t r, o, size = 65535;
+ char *end;
+ bool use_sendfile = false;
+ int opt, sock, fd = 0, gai;
+
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_socktype = SOCK_DGRAM;
+
+ while ((opt = getopt(argc, argv, "46dn:p:s")) != EOF) {
+ switch (opt) {
+ case '4':
+ hints.ai_family = AF_INET;
+ break;
+ case '6':
+ hints.ai_family = AF_INET6;
+ break;
+ case 'd':
+ flags |= O_DIRECT;
+ break;
+ case 'n':
+ size = strtoul(optarg, &end, 0);
+ switch (*end) {
+ case 'K':
+ case 'k':
+ size *= 1024;
+ break;
+ }
+ if (size > 65535) {
+ fprintf(stderr,
+ "Too much data for UDP packet\n");
+ exit(2);
+ }
+ break;
+ case 'p':
+ service = optarg;
+ break;
+ case 's':
+ use_sendfile = true;
+ break;
+ default:
+ format();
+ }
+ }
+
+ argc -= optind;
+ argv += optind;
+ if (argc != 2)
+ format();
+ filename = argv[0];
+ sockname = argv[1];
+
+ gai = getaddrinfo(sockname, service, &hints, &addrs);
+ if (gai) {
+ fprintf(stderr, "%s: %s\n", sockname, gai_strerror(gai));
+ exit(3);
+ }
+
+ if (!addrs) {
+ fprintf(stderr, "%s: No addresses\n", sockname);
+ exit(3);
+ }
+
+ sockname = addrs->ai_canonname;
+ sock = socket(addrs->ai_family, addrs->ai_socktype, addrs->ai_protocol);
+ OSERROR(sock, "socket");
+ OSERROR(connect(sock, addrs->ai_addr, addrs->ai_addrlen), "connect");
+
+ if (strcmp(filename, "-") != 0) {
+ fd = open(filename, flags);
+ OSERROR(fd, filename);
+ OSERROR(fstat(fd, &st), filename);
+ if (size > st.st_size)
+ size = st.st_size;
+ } else {
+ OSERROR(fstat(fd, &st), filename);
+ }
+
+ len = htonl(size);
+ OSERROR(send(sock, &len, 4, MSG_MORE), "sock/send");
+
+ if (!use_sendfile) {
+ while (size) {
+ r = read(fd, buffer, sizeof(buffer));
+ OSERROR(r, filename);
+ if (r == 0)
+ break;
+ size -= r;
+
+ o = 0;
+ do {
+ ssize_t w = send(sock, buffer + o, r - o,
+ size > 0 ? MSG_MORE : 0);
+ OSERROR(w, "sock/send");
+ o += w;
+ } while (o < r);
+ }
+ } else if (S_ISFIFO(st.st_mode)) {
+ r = splice(fd, NULL, sock, NULL, size, 0);
+ OSERROR(r, "sock/splice");
+ if (r != size) {
+ fprintf(stderr, "Short splice\n");
+ exit(1);
+ }
+ } else {
+ r = sendfile(sock, fd, NULL, size);
+ OSERROR(r, "sock/sendfile");
+ if (r != size) {
+ fprintf(stderr, "Short sendfile\n");
+ exit(1);
+ }
+ }
+
+ OSERROR(close(sock), "sock/close");
+ OSERROR(close(fd), "close");
+ return 0;
+}
diff --git a/samples/net/udp-sink.c b/samples/net/udp-sink.c
new file mode 100644
index 000000000000..f23c64acec4a
--- /dev/null
+++ b/samples/net/udp-sink.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * UDP sink server
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <getopt.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <netinet/in.h>
+
+#define OSERROR(X, Y) \
+ do { if ((long)(X) == -1) { perror(Y); exit(1); } } while (0)
+
+static unsigned char buffer[512 * 1024];
+
+static void format(void)
+{
+ fprintf(stderr, "udp-sink [-4][-p<port>]\n");
+ exit(2);
+}
+
+int main(int argc, char *argv[])
+{
+ struct iovec iov[1] = {
+ [0] = {
+ .iov_base = buffer,
+ .iov_len = sizeof(buffer),
+ },
+ };
+ struct msghdr msg = {
+ .msg_iov = iov,
+ .msg_iovlen = 1,
+ };
+ unsigned int port = 5555;
+ bool ipv6 = true;
+ int opt, sock;
+
+ while ((opt = getopt(argc, argv, "4p:")) != EOF) {
+ switch (opt) {
+ case '4':
+ ipv6 = false;
+ break;
+ case 'p':
+ port = atoi(optarg);
+ break;
+ default:
+ format();
+ }
+ }
+
+ if (!ipv6) {
+ struct sockaddr_in sin = {
+ .sin_family = AF_INET,
+ .sin_port = htons(port),
+ };
+ sock = socket(AF_INET, SOCK_DGRAM, 0);
+ OSERROR(sock, "socket");
+ OSERROR(bind(sock, (struct sockaddr *)&sin, sizeof(sin)),
+ "bind");
+ } else {
+ struct sockaddr_in6 sin6 = {
+ .sin6_family = AF_INET6,
+ .sin6_port = htons(port),
+ };
+ sock = socket(AF_INET6, SOCK_DGRAM, 0);
+ OSERROR(sock, "socket");
+ OSERROR(bind(sock, (struct sockaddr *)&sin6, sizeof(sin6)),
+ "bind");
+ }
+
+ for (;;) {
+ ssize_t r;
+
+ r = recvmsg(sock, &msg, 0);
+ printf("rx %zd\n", r);
+ }
+}
diff --git a/samples/net/unix-send.c b/samples/net/unix-send.c
new file mode 100644
index 000000000000..5950fcf1ccd2
--- /dev/null
+++ b/samples/net/unix-send.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * AF_UNIX stream send client. Pass -s to use splice/sendfile.
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <getopt.h>
+#include <limits.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/un.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/sendfile.h>
+
+#define OSERROR(X, Y) \
+ do { if ((long)(X) == -1) { perror(Y); exit(1); } } while (0)
+#define min(x, y) ((x) < (y) ? (x) : (y))
+
+static unsigned char buffer[4096];
+
+static void format(void)
+{
+ fprintf(stderr, "unix-send [-ds] [-n<size>] <file>|- <socket-file>\n");
+ exit(2);
+}
+
+int main(int argc, char *argv[])
+{
+ struct sockaddr_un sun = { .sun_family = AF_UNIX, };
+ struct stat st;
+ const char *filename, *sockname;
+ unsigned int flags = O_RDONLY;
+ ssize_t r, w, o, size = LONG_MAX;
+ size_t plen, total = 0;
+ char *end;
+ bool use_sendfile = false, all = true;
+ int opt, sock, fd = 0;
+
+ while ((opt = getopt(argc, argv, "dn:s")) != EOF) {
+ switch (opt) {
+ case 'd':
+ flags |= O_DIRECT;
+ break;
+ case 'n':
+ size = strtoul(optarg, &end, 0);
+ switch (*end) {
+ case 'K':
+ case 'k':
+ size *= 1024;
+ break;
+ case 'M':
+ case 'm':
+ size *= 1024 * 1024;
+ break;
+ }
+ all = false;
+ break;
+ case 's':
+ use_sendfile = true;
+ break;
+ default:
+ format();
+ }
+ }
+
+ argc -= optind;
+ argv += optind;
+ if (argc != 2)
+ format();
+ filename = argv[0];
+ sockname = argv[1];
+
+ plen = strlen(sockname);
+ if (plen == 0 || plen > sizeof(sun.sun_path) - 1) {
+ fprintf(stderr, "socket filename too short or too long\n");
+ exit(2);
+ }
+ memcpy(sun.sun_path, sockname, plen + 1);
+
+ sock = socket(AF_UNIX, SOCK_STREAM, 0);
+ OSERROR(sock, "socket");
+ OSERROR(connect(sock, (struct sockaddr *)&sun, sizeof(sun)), "connect");
+
+ if (strcmp(filename, "-") != 0) {
+ fd = open(filename, flags);
+ OSERROR(fd, filename);
+ OSERROR(fstat(fd, &st), filename);
+ if (size > st.st_size)
+ size = st.st_size;
+ } else {
+ OSERROR(fstat(fd, &st), argv[2]);
+ }
+
+ if (!use_sendfile) {
+ bool more = false;
+
+ while (size) {
+ r = read(fd, buffer, min(sizeof(buffer), size));
+ OSERROR(r, filename);
+ if (r == 0)
+ break;
+ size -= r;
+
+ o = 0;
+ do {
+ more = size > 0;
+ w = send(sock, buffer + o, r - o,
+ more ? MSG_MORE : 0);
+ OSERROR(w, "sock/send");
+ o += w;
+ total += w;
+ } while (o < r);
+ }
+
+ if (more)
+ send(sock, NULL, 0, 0);
+ } else if (S_ISFIFO(st.st_mode)) {
+ do {
+ r = splice(fd, NULL, sock, NULL, size,
+ size > 0 ? SPLICE_F_MORE : 0);
+ OSERROR(r, "sock/splice");
+ size -= r;
+ total += r;
+ } while (r > 0 && size > 0);
+ if (size && !all) {
+ fprintf(stderr, "Short splice\n");
+ exit(1);
+ }
+ } else {
+ r = sendfile(sock, fd, NULL, size);
+ OSERROR(r, "sock/sendfile");
+ if (r != size) {
+ fprintf(stderr, "Short sendfile\n");
+ exit(1);
+ }
+ total += r;
+ }
+
+ printf("Sent %zu bytes\n", total);
+ OSERROR(close(sock), "sock/close");
+ OSERROR(close(fd), "close");
+ return 0;
+}
diff --git a/samples/net/unix-sink.c b/samples/net/unix-sink.c
new file mode 100644
index 000000000000..9f0a5ac9c578
--- /dev/null
+++ b/samples/net/unix-sink.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * UNIX stream sink server
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/un.h>
+#include <sys/socket.h>
+
+#define OSERROR(X, Y) \
+ do { if ((long)(X) == -1) { perror(Y); exit(1); } } while (0)
+
+static unsigned char buffer[512 * 1024];
+
+int main(int argc, char *argv[])
+{
+ struct sockaddr_un sun = { .sun_family = AF_UNIX, };
+ size_t plen;
+ int server_sock, sock;
+
+ if (argc != 2) {
+ fprintf(stderr, "unix-sink <socket-file>\n");
+ exit(2);
+ }
+
+ plen = strlen(argv[1]);
+ if (plen == 0 || plen > sizeof(sun.sun_path) - 1) {
+ fprintf(stderr, "socket filename too short or too long\n");
+ exit(2);
+ }
+ memcpy(sun.sun_path, argv[1], plen + 1);
+
+ server_sock = socket(AF_UNIX, SOCK_STREAM, 0);
+ OSERROR(server_sock, "socket");
+ OSERROR(bind(server_sock, (struct sockaddr *)&sun, sizeof(sun)),
+ "bind");
+ OSERROR(listen(server_sock, 1), "listen");
+
+ for (;;) {
+ sock = accept(server_sock, NULL, NULL);
+ if (sock != -1) {
+ while (read(sock, buffer, sizeof(buffer)) > 0)
+ ;
+ close(sock);
+ }
+ }
+}