[PATCH v2 10/12] mini-os: add struct file_ops for file type socket

[Juergen Gross <jgross@xxxxxxxx>]

Even with some special handling needed in select_poll(), add a struct
file_ops for FTYPE_SOCKET. Due to the need of the special handling it
isn't possible to use a dynamically allocated file type.

Most functions calling the file_ops methods can be simplified a lot now
that no file type specific handling is left. Same applies to the file
type name printing in debug/verbose mode.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
 lib/sys.c | 153 +++++++++++++++++++++++++-----------------------------
 1 file changed, 70 insertions(+), 83 deletions(-)

diff --git a/lib/sys.c b/lib/sys.c
index 3a8aa68..12deaed 100644
--- a/lib/sys.c
+++ b/lib/sys.c
@@ -99,11 +99,70 @@ static struct file_ops file_ops_none = {
     .name = "none",
 };
 
+#ifdef HAVE_LWIP
+static int socket_read(int fd, void *buf, size_t nbytes)
+{
+    return lwip_read(fd, buf, nbytes);
+}
+
+static int socket_write(int fd, const void *buf, size_t nbytes)
+{
+    return lwip_write(fd, (void *)buf, nbytes);
+}
+
+static int close_socket_fd(int fd)
+{
+    struct file *file = get_file_from_fd(fd);
+
+    return lwip_close(file->fd);
+}
+
+static int socket_fstat(int fd, struct stat *buf)
+{
+    buf->st_mode = S_IFSOCK | S_IRUSR | S_IWUSR;
+    buf->st_atime = buf->st_mtime = buf->st_ctime = time(NULL);
+
+    return 0;
+}
+
+static int socket_fcntl(int fd, int cmd, va_list args)
+{
+    long arg;
+    struct file *file = get_file_from_fd(fd);
+
+    arg = va_arg(args, long);
+
+    if ( cmd == F_SETFL && !(arg & ~O_NONBLOCK) )
+    {
+        /* Only flag supported: non-blocking mode */
+        uint32_t nblock = !!(arg & O_NONBLOCK);
+
+        return lwip_ioctl(file->fd, FIONBIO, &nblock);
+    }
+
+    printk("fcntl(%d, %d, %lx/%lo)\n", fd, cmd, arg, arg);
+    errno = ENOSYS;
+    return -1;
+}
+
+static struct file_ops socket_ops = {
+    .name = "socket",
+    .read = socket_read,
+    .write = socket_write,
+    .close = close_socket_fd,
+    .fstat = socket_fstat,
+    .fcntl = socket_fcntl,
+};
+#endif
+
 static struct file_ops *file_ops[FTYPE_N + FTYPE_SPARE] = {
     [FTYPE_NONE] = &file_ops_none,
 #ifdef CONFIG_CONSFRONT
     [FTYPE_CONSOLE] = &console_ops,
 #endif
+#ifdef HAVE_LWIP
+    [FTYPE_SOCKET] = &socket_ops,
+#endif
 };
 
 unsigned int alloc_file_type(struct file_ops *ops)
@@ -282,14 +341,6 @@ int read(int fd, void *buf, size_t nbytes)
     if ( ops->read )
         return ops->read(fd, buf, nbytes);
 
-    switch (files[fd].type) {
-#ifdef HAVE_LWIP
-       case FTYPE_SOCKET:
-           return lwip_read(files[fd].fd, buf, nbytes);
-#endif
-       default:
-           break;
-    }
     printk("read(%d): Bad descriptor\n", fd);
     errno = EBADF;
     return -1;
@@ -302,14 +353,6 @@ int write(int fd, const void *buf, size_t nbytes)
     if ( ops->write )
         return ops->write(fd, buf, nbytes);
 
-    switch (files[fd].type) {
-#ifdef HAVE_LWIP
-       case FTYPE_SOCKET:
-           return lwip_write(files[fd].fd, (void*) buf, nbytes);
-#endif
-       default:
-           break;
-    }
     printk("write(%d): Bad descriptor\n", fd);
     errno = EBADF;
     return -1;
@@ -378,26 +421,14 @@ int close(int fd)
 
     printk("close(%d)\n", fd);
     if ( ops->close )
-    {
         res = ops->close(fd);
-        goto out;
-    }
-
-    switch (files[fd].type) {
-        default:
-            break;
-#ifdef HAVE_LWIP
-       case FTYPE_SOCKET:
-           res = lwip_close(files[fd].fd);
-            break;
-#endif
-       case FTYPE_NONE:
-            printk("close(%d): Bad descriptor\n", fd);
-            errno = EBADF;
-            return -1;
+    else if ( files[fd].type == FTYPE_NONE )
+    {
+        printk("close(%d): Bad descriptor\n", fd);
+        errno = EBADF;
+        return -1;
     }
 
- out:
     memset(files + fd, 0, sizeof(struct file));
     files[fd].type = FTYPE_NONE;
     return res;
@@ -429,21 +460,6 @@ int fstat(int fd, struct stat *buf)
     if ( ops->fstat )
         return ops->fstat(fd, buf);
 
-    switch (files[fd].type) {
-       case FTYPE_SOCKET: {
-            buf->st_mode = S_IFSOCK|S_IRUSR|S_IWUSR;
-           buf->st_uid = 0;
-           buf->st_gid = 0;
-           buf->st_size = 0;
-           buf->st_atime = 
-           buf->st_mtime = 
-           buf->st_ctime = time(NULL);
-           return 0;
-       }
-       default:
-           break;
-    }
-
     printk("statf(%d): Bad descriptor\n", fd);
     errno = EBADF;
     return -1;
@@ -491,21 +507,9 @@ int fcntl(int fd, int cmd, ...)
     arg = va_arg(ap, long);
     va_end(ap);
 
-    switch (cmd) {
-#ifdef HAVE_LWIP
-       case F_SETFL:
-           if (files[fd].type == FTYPE_SOCKET && !(arg & ~O_NONBLOCK)) {
-               /* Only flag supported: non-blocking mode */
-               uint32_t nblock = !!(arg & O_NONBLOCK);
-               return lwip_ioctl(files[fd].fd, FIONBIO, &nblock);
-           }
-           /* Fallthrough */
-#endif
-       default:
-           printk("fcntl(%d, %d, %lx/%lo)\n", fd, cmd, arg, arg);
-           errno = ENOSYS;
-           return -1;
-    }
+    printk("fcntl(%d, %d, %lx/%lo)\n", fd, cmd, arg, arg);
+    errno = ENOSYS;
+    return -1;
 }
 
 DIR *opendir(const char *name)
@@ -539,23 +543,6 @@ int closedir(DIR *dir)
 
 /* We assume that only the main thread calls select(). */
 
-#if defined(LIBC_DEBUG) || defined(LIBC_VERBOSE)
-static const char *file_types[] = {
-    [FTYPE_NONE]    = "none",
-    [FTYPE_SOCKET]  = "socket",
-};
-
-static char *get_type_name(unsigned int type)
-{
-    if ( type < ARRAY_SIZE(file_ops) && file_ops[type] )
-        return file_ops[type]->name;
-
-    if ( type < ARRAY_SIZE(file_types) && file_types[type] )
-        return file_types[type];
-
-    return "none";
-}
-#endif
 #ifdef LIBC_DEBUG
 static void dump_set(int nfds, fd_set *readfds, fd_set *writefds, fd_set 
*exceptfds, struct timeval *timeout)
 {
@@ -566,7 +553,7 @@ static void dump_set(int nfds, fd_set *readfds, fd_set 
*writefds, fd_set *except
        if (FD_ISSET(i, set)) { \
            if (comma) \
                printk(", "); \
-           printk("%d(%s)", i, get_type_name(files[i].type)); \
+           printk("%d(%s)", i, get_file_ops(files[i].type)->name); \
            comma = 1; \
        } \
     } \
@@ -600,7 +587,7 @@ static void dump_pollfds(struct pollfd *pfd, int nfds, int 
timeout)
         fd = pfd[i].fd;
         if (comma)
             printk(", ");
-        printk("%d(%s)/%02x", fd, get_type_name(files[fd].type),
+        printk("%d(%s)/%02x", fd, get_file_ops(files[fd].type)->name,
             pfd[i].events);
             comma = 1;
     }
@@ -754,7 +741,7 @@ static int select_poll(int nfds, fd_set *readfds, fd_set 
*writefds, fd_set *exce
        printk("%d(%d): ", nb, sock_n);
        for (i = 0; i < nfds; i++) {
            if (nbread[i] || nbwrite[i] || nbexcept[i])
-               printk(" %d(%c):", i, get_type_name(files[i].type));
+               printk(" %d(%c):", i, get_file_ops(files[i].type)->name);
            if (nbread[i])
                printk(" %dR", nbread[i]);
            if (nbwrite[i])
-- 
2.26.2