mm: relay mmap() to external server

src/include/kernel/memory.h

@@ -108,6 +108,6 @@ uintptr_t mmio(Thread *, uintptr_t, off_t, int);
 uintptr_t pcontig(Thread *, uintptr_t, off_t, int);
 uintptr_t vtop(Thread *, uintptr_t);
 
-void *mmap(Thread *, void *, size_t, int, int, int, off_t);
+void *mmap(Thread *, uint64_t, void *, size_t, int, int, int, off_t);
 int munmap(Thread *, void *, size_t);
-int msync(Thread *, void *, size_t, int);
+int msync(Thread *, uint64_t, void *, size_t, int);

src/memory/mmap.c

@@ -0,0 +1,63 @@
+/*
+ * lux - a lightweight unix-like operating system
+ * Omar Elghoul, 2024
+ * 
+ * Core Microkernel
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <kernel/memory.h>
+#include <kernel/file.h>
+#include <kernel/sched.h>
+#include <kernel/servers.h>
+
+/* mmap(): creates a memory mapping for a file descriptor
+ * params: t - calling thread
+ * params: id - syscall ID
+ * params: addr - process-suggested address
+ * params: len - length of the mapping
+ * params: prot - protection flags
+ * params: flags - mapping flags
+ * params: fd - file descriptor
+ * params: off - offset into file descriptor
+ * returns: pointer to the memory mapping, negative error code on fail
+ */
+
+void *mmap(Thread *t, uint64_t id, void *addr, size_t len, int prot, int flags,
+           int fd, off_t off) {
+    if(fd < 0 || fd > MAX_IO_DESCRIPTORS) return (void *) -EBADF;
+    MmapCommand *command = calloc(1, sizeof(MmapCommand));
+    if(!command) return (void *) -ENOMEM;
+
+    Process *p = getProcess(t->pid);
+    if(!p) return (void *) -ESRCH;
+
+    IODescriptor *io = &p->io[fd];
+    if(io->valid || !io->data) return (void *) -EBADF;
+    if(io->type != IO_FILE) return (void *) -ENODEV;
+
+    FileDescriptor *f = (FileDescriptor *) io->data;
+
+    command->header.header.command = COMMAND_MMAP;
+    command->header.header.length = sizeof(MmapCommand);
+    command->header.id = id;
+    command->uid = p->user;
+    command->gid = p->group;
+    command->position = f->position;
+    command->openFlags = io->flags;
+    command->id = f->id;
+    strcpy(command->device, f->device);
+    strcpy(command->path, f->abspath);
+
+    command->len = len;
+    command->prot = prot;
+    command->flags = flags;
+    command->off = off;
+
+    int status = requestServer(t, command);
+    free(command);
+    return (void *) (intptr_t) status;
+}