First commit

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 86 insertions, 0 deletions

diff --git a/libsbus.c b/libsbus.c
new file mode 100644
index 0000000..bbd0b4f
--- /dev/null
+++ b/libsbus.c
@@ -0,0 +1,86 @@
+/* See LICENSE file for copyright and license details. */
+#include "libsbus.h"
+#include <sys/socket.h>
+#include <errno.h>
+#include <string.h>
+
+int
+libsbus_subscribe(int fd, const char *pattern, char *buf)
+{
+	size_t n = strlen(pattern);
+	if (n + 4 > LIBSBUS_BUFFER_SIZE) {
+		errno = EMSGSIZE;
+		return -1;
+	}
+	buf[0] = 'S', buf[1] = 'U', buf[2] = 'B', buf[3] = ' ';
+	memcpy(&buf[4], pattern, n);
+	return -(send(fd, buf, n + 4, 0) < 0);
+}
+
+int
+libsbus_unsubscribe(int fd, const char *pattern, char *buf)
+{
+	size_t n = strlen(pattern);
+	if (n + 6 > LIBSBUS_BUFFER_SIZE) {
+		errno = EMSGSIZE;
+		return -1;
+	}
+	buf[0] = 'U', buf[1] = 'N', buf[2] = 'S', buf[3] = 'U', buf[4] = 'B', buf[5] = ' ';
+	memcpy(&buf[6], pattern, n);
+	return -(send(fd, buf, n + 6, 0) < 0);
+}
+
+int
+libsbus_publish(int fd, const char *key, const char *msg, size_t n, char *buf)
+{
+	size_t len = strlen(key) + 1;
+	if (len + n > LIBSBUS_BUFFER_SIZE - 4) {
+		errno = EMSGSIZE;
+		return -1;
+	}
+	buf[0] = 'M', buf[1] = 'S', buf[2] = 'G', buf[3] = ' ';
+	memcpy(&buf[4], key, len);
+	memcpy(&buf[4 + len], msg, n);
+	return -(send(fd, buf, len + n + 4, 0) < 0);
+}
+
+ssize_t
+libsbuf_prepare_message(const char *key, char *buf, size_t *remaining)
+{
+	size_t len = strlen(key) + 1;
+	if (len > LIBSBUS_BUFFER_SIZE - 4) {
+		errno = EMSGSIZE;
+		return -1;
+	}
+	buf[0] = 'M', buf[1] = 'S', buf[2] = 'G', buf[3] = ' ';
+	memcpy(&buf[4], key, len);
+	len += 4;
+	*remaining = LIBSBUS_BUFFER_SIZE - len;
+	return (ssize_t)len;
+}
+
+int
+libsbus_receive(int fd, char *buf, union libsbus_packet *packet)
+{
+	ssize_t r;
+	char *p;
+
+	r = recv(fd, buf, LIBSBUS_BUFFER_SIZE, 0);
+	if (r < 0)
+		return -1;
+
+	if (!strncmp(buf, "MSG ", 4)) {
+		p = memchr(buf, '\0', r);
+		if (!*p++)
+			goto unknown;
+		packet->type = LIBSBUS_MESSAGE;
+		packet->message.key = &buf[4];
+		packet->message.msg = p;
+		packet->message.n = (size_t)(r - (p - buf));
+	} else {
+	unknown:
+		packet->type = LIBSBUS_UNKNOWN;
+		packet->unknown.n = (size_t)r;
+	}
+	return 0;
+}