handle /etc/hostname, sethostname(2), gethostname(2) and uname(2)

kernel-src/sys/syscalls/hostname.c

@@ -0,0 +1,61 @@
+#include <kernel/syscalls.h>
+#include <kernel/abi.h>
+#include <spinlock.h>
+#include <util.h>
+
+static spinlock_t lock;
+static char buffer[HOST_NAME_MAX];
+static size_t bufferlen;
+
+void hostname_get(char *buf) {
+	bool intstatus = interrupt_set(false);
+	spinlock_acquire(&lock);
+
+	memcpy(buf, buffer, bufferlen);
+	buf[bufferlen] = '\0';
+
+	spinlock_release(&lock);
+	interrupt_set(intstatus);
+}
+
+syscallret_t syscall_hostname(context_t *, char *unew, size_t newsize, char *uold, size_t oldsize) {
+	syscallret_t ret = {
+		.ret = -1
+	};
+
+	if ((unew && newsize > HOST_NAME_MAX) || (uold && oldsize == 0)) {
+		ret.errno = EINVAL;
+		return ret;
+	}
+
+	char new[HOST_NAME_MAX];
+	char old[HOST_NAME_MAX + 1];
+
+	if (unew)
+		memcpy(new, unew, newsize);
+
+	interrupt_set(false);
+	spinlock_acquire(&lock);
+
+	if (uold) {
+		size_t copysize = min(oldsize - 1, bufferlen);
+
+		memcpy(old, buffer, copysize);
+		old[copysize] = '\0';
+	}
+
+	if (unew) {
+		bufferlen = newsize;
+		strcpy(buffer, new);
+	}
+
+	spinlock_release(&lock);
+	interrupt_set(true);
+
+	if (uold)
+		strcpy(uold, old);
+
+	ret.errno = 0;
+	ret.ret = 0;
+	return ret;
+}

kernel-src/sys/syscalls/uname.c

@@ -0,0 +1,29 @@
+#include <kernel/syscalls.h>
+#include <build.h>
+
+typedef struct {
+	char sysname[65];
+	char nodename[65];
+	char release[65];
+	char version[65];
+	char machine[65];
+	char domainname[65];
+} utsname_t;
+
+void hostname_get(char *buf);
+
+syscallret_t syscall_uname(context_t *, utsname_t *utsname) {
+	syscallret_t ret = {0};
+
+	char hostname[HOST_NAME_MAX + 1];
+	hostname_get(hostname);
+
+	strcpy(utsname->sysname, "Astral");
+	strcpy(utsname->nodename, hostname);
+	strcpy(utsname->release, "Astral");
+	strcpy(utsname->version, BUILD_DATE);
+	strcpy(utsname->machine, BUILD_TARGET);
+	strcpy(utsname->domainname, hostname);
+
+	return ret;
+}