misc porth stuff test

..porth-stuff.md

porth-stuff

Just some random programs in porth because I saw Tsoding's videos/stream and I thought it looked cool.

Licence: MIT

.gitignore

# Ignore all without extensions
*
!*.*

*.asm
*.o

nothttpd.porth

// A really bad http server example in Porth
// It does not comply to anything. (yet?)

const SERVER_PORT 8080 end

include "../porth/std/std.porth"

const AF_INET 2 end
const SOCK_STREAM 1 end
const SOL_SOCKET 1 end
const SO_REUSEADDR 2 end
const O_DIRECTORY 65536 end

const S_IFMT 61440 end // 00170000 
const S_IFREG 32768 end // 0x0100000 
const S_IFDIR 16384 end // 0x0040000 

inline proc S_ISREG int -- bool in S_IFMT and S_IFREG = end
inline proc S_ISDIR int -- bool in S_IFMT and S_IFDIR = end

const sizeof(sockaddr) 16 end
const sizeof(linux_dirent) 1024 end

proc main in
  memory socket sizeof(int) end
  memory sockaddr sizeof(sockaddr) end
  memory connection sizeof(int) end

  memory dirent_buf sizeof(linux_dirent) end
  memory stat_buf sizeof(stat) end

  const client_read_buf_size 1024 end
  memory client_read_buf client_read_buf_size end

  const file_buf_size 1024 end
  memory file_buf file_buf_size end

  // Create socket
  // socket(AF_INET, SOCK_STREAM, 0)
  0 SOCK_STREAM AF_INET SYS_socket syscall3
  dup 0 < if
    "ERROR: Could not create socket, errcode " eputs
    dup print
    1 exit
  end
  socket !64
  "INFO: Got socket.\n" eputs

  // We make the socket's address reusable for better debugging
  // setsockopt(socket, level, option_name, *option_value, option_len)
  // Load '1' into the temp buffer area
  memory ONE 8 end
  1 ONE !8
  8 ONE SO_REUSEADDR SOL_SOCKET socket @64 SYS_setsockopt syscall5 drop

  // Now we make the 'sockaddr' struct to pass into bind()
  // struct sockaddr_in {
  //     sa_family_t    sin_family; /* address family: AF_INET */
  //     in_port_t      sin_port;   /* port in network byte order */
  //     struct in_addr sin_addr;   /* internet address */
  // };
  //
  // struct in_addr {
  //     uint32_t       s_addr;     /* address in network byte order */
  // };

  // Keep in mind little endian
  // sin_family 16 bit unsigned int
  AF_INET sockaddr        !8
  0       sockaddr 1 ptr+ !8
  // sin_port 16 bit (network byte order)
  // e.g. port 3000 - 00001011 10111000 = 11 184
  // we can shift and truncate into the 1byte memory locations
  SERVER_PORT 8 shr sockaddr 2 ptr+ !8
  SERVER_PORT       sockaddr 3 ptr+ !8
  // sin_addr 32 bit (in_addr.s_addr) listen on 0.0.0.0
  0 sockaddr 4 ptr+ !32

  // Actually bind
  // bind(socket_fd, &sockaddr, size)
  16 sockaddr socket @64 SYS_bind syscall3
  dup 0 < if
    "ERROR: Could not bind, errcode " eputs
    dup print
    1 exit
  end drop
  "INFO: Bound socket on all addresses to port " eputs
  SERVER_PORT print

  // Listen to the socket now that it's bound (queue 2)
  2 socket @64 SYS_listen syscall2
  dup 0 < if
    "ERROR: Could not listen, errcode " eputs
    dup print
    1 exit
  end drop
  "INFO: Listening.\n" eputs

  // Accept any connections that come our way and serve them our HTTP :^)
  //while 1 cast(bool) do
  while true do
    0 0 socket @64 SYS_accept syscall3
    dup 0 < if
      "WARN: Failed to accept a connection, errcode " eputs
      print
    else
      "INFO: Accepted a connection.\n" eputs

      // Accepted connection gives us another fd to write back to them
      // Keep another one on the stack to close later
      dup connection !64

      // TODO: Handle writes failing with a debug message (when we can break loops?)

      // Read the TCP contents
      client_read_buf_size client_read_buf connection @64 read
      dup 0 < if
        "WARN: Error reading from socket but going to continue! errcode " eputs
        print
      else
        drop

        "\n\nDEBUG: The client said...\n----------\n" eputs
        client_read_buf dup cstrlen swap eputs
        "\n----------\n\n" eputs

        // Read "GET", return error otherwise
        // FIXME: This is a hacky way of just reading and comparing as null terminated, but it works I guess (but it destroys the original read buffer)
        0 client_read_buf 3 ptr+ !8
        client_read_buf "GET"c cstreq if
          "It was a GET\n" eputs

          // TODO: Skip over "GET " and then get the path until a " "
          // FIXME: Another hack. We go until the " " (ASCII 32) and add a null terminator there and then we can use it as a C string.
          // The string will be at 'client_read_buf 4 +'
          client_read_buf 4 ptr+
          while dup @8 dup 32 != swap 0 != land do // keep going until space or end of string
            1 ptr+
          end 0 swap !8

          // FIXME: Another weird thing we can do. Set 'client_read_buf 3 +' as '.' (ASCII 46), then we can use that whole C string as the path to read locally.
          46 client_read_buf 3 ptr+ !8

          "Trying to stat '" eputs
          client_read_buf 3 ptr+ dup cstrlen swap eputs
          "'...\n" eputs

          // stat() the path to test if dir/file/unknown
          stat_buf client_read_buf 3 ptr+ stat
          0 < if
            "Couldn't stat.\n" eputs
            "HTTP/1.0 404 OK\nContent-Type: text/html\n\n<html><head><title>Error</title></head><body>File not found.</body></html>" connection @64 fputs
          else
            // Determine if file or folder with st_mode
            // struct stat {
            //     dev_t     st_dev;         /* ID of device containing file */
            //     ino_t     st_ino;         /* Inode number */
            //     mode_t    st_mode;        /* File type and mode */
            //     ...
            // }
            // mode_t will (probably) be 16 bytes in, and is 4 bytes long - read it as such (little endian)
            // TODO: Turn this into a macro to read these various lengths/at least more elegant?

            stat_buf stat.st_mode @32

            // TODO: If file, read file and send back
            // TODO:     Determine Content-Type to send back nicely
            // TODO: If dir, read that dir and send back
            // TODO: Else, return error
            dup S_ISREG if
              // Just open and serve the file
              0 client_read_buf 3 ptr+ SYS_open syscall2
              dup 0 < if
                "HTTP/1.0 500 OK\nContent-Type: text/html\n\n<html><head><title>Error</title></head><body>Could not open the file.</body></html>" connection @64 fputs
                "WARN: Could not open file! errcode " eputs
                print
              else
                "HTTP/1.0 200 OK\nContent-Type: " connection @64 fputs

                // TODO: Handle types properly
                // Naive .html ending check
                client_read_buf 3 ptr+ cstrlen

                dup 7 > swap
                5 - client_read_buf 3 ptr+ swap ptr+ ".html"c cstreq
                land if
                  "HTML found\n" eputs
                  "text/html" connection @64 fputs
                else
                  "Not HTML, serving as plain text\n" eputs
                  "text/plain" connection @64 fputs
                end

                "\n\n" connection @64 fputs

                // Read in the file (fd is on the stack, save a copy)
                // (also, read returns the bytes read)
                // TODO: fix this awkward read twice syntax
                dup file_buf_size swap file_buf swap read
                while dup 0 > do
                  file_buf connection @64 fputs
                  dup file_buf_size swap file_buf swap read
                end drop

                // Close the file as we're done
                close drop
              end
            else dup S_ISDIR if*
              // Enumerate folder contents
              // Open directory, then read its contents
              O_DIRECTORY client_read_buf 3 ptr+ SYS_open syscall2
              dup 0 < if
                "HTTP/1.0 500 OK\nContent-Type: text/html\n\n<html><head><title>Error</title></head><body>Could not open the directory.</body></html>" connection @64 fputs
                "WARN: Could not open directory! errcode " eputs
                print
              else
                "HTTP/1.0 200 OK\nContent-Type: text/html\n\n<html><head><title>Directory listing</title></head><body><h1>Directory listing for " connection @64 fputs
                client_read_buf 3 ptr+ dup cstrlen swap connection @64 fputs
                "</h1><ul>" connection @64 fputs

                "INFO: Reading directory...\n" eputs

                // Do the content reading of the directory stream
                // (keep pointer to opendir with dup)
                // getdents(fd, buf, buf_size)
                dup sizeof(linux_dirent) swap dirent_buf swap SYS_getdents syscall3
                while dup 0 > do
                  // Enumerate the contents as per returned, keep the offset on the stack
                  // Initial as 0
                  0 while over over > do
                    // We have a 'Linux dirent'
                    //
                    // struct linux_dirent {
                    //     unsigned long  d_ino;
                    //     off_t          d_off;
                    //     unsigned short d_reclen;
                    //     char           d_name[];
                    // };
                    //
                    // So to jump to the filename, we jump 18 bytes (8+8+2)
                    // TODO: sizeof() - will we ever run into any issues with this assumption?

                    // Main pointer to linux_dirent struct
                    dup dirent_buf swap ptr+

                    // Add in offset and jump to filename
                    "<li><a href=\"./" connection @64 fputs
                    dup 18 ptr+ dup cstrlen swap connection @64 fputs
                    "\">" connection @64 fputs
                    dup 18 ptr+ dup cstrlen swap connection @64 fputs
                    "</a></li>" connection @64 fputs

                    // Jump by the offset 'd_reclen'
                    // ... it is a unsigned short, so we'll need to deal with it as such...
                    // (Remember little endian)
                    16 ptr+ @16 +
                  end drop drop // drop twice to get rid of the extra duped getdents return value as well

                  // TODO: Fix this awkward syntax
                  dup sizeof(linux_dirent) swap dirent_buf swap SYS_getdents syscall3
                end drop

                "INFO: Closing directory...\n" eputs
                close drop

                "</ul><i>powered by porth-nothttpd</i></body></html>\n" connection @64 fputs
                "INFO: Replied to connection with directory listing.\n" eputs

              end
            else
              "Not a regular file or directory.\n" eputs
              "HTTP/1.0 404 OK\nContent-Type: text/html\n\n<html><head><title>Error</title></head><body>File not found.</body></html>" connection @64 fputs
            end drop
          end
        else
          "It was NOT a GET\n" eputs
          "HTTP/1.0 400 OK\nContent-Type: text/html\n\n<html><head><title>Error</title></head><body>The server does not accept non-GET requests.</body></html>" connection @64 fputs
        end
      end

      "INFO: Closing connection.\n" eputs
      close drop
    end
  end
end