| /* Host file transfer support for gdbserver. |
| Copyright (C) 2007-2024 Free Software Foundation, Inc. |
| |
| Contributed by CodeSourcery. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "gdbsupport/fileio.h" |
| #include "hostio.h" |
| |
| #include <fcntl.h> |
| #include <limits.h> |
| #include <unistd.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include "gdbsupport/fileio.h" |
| |
| struct fd_list |
| { |
| int fd; |
| struct fd_list *next; |
| }; |
| |
| static struct fd_list *open_fds; |
| |
| static int |
| safe_fromhex (char a, int *nibble) |
| { |
| if (a >= '0' && a <= '9') |
| *nibble = a - '0'; |
| else if (a >= 'a' && a <= 'f') |
| *nibble = a - 'a' + 10; |
| else if (a >= 'A' && a <= 'F') |
| *nibble = a - 'A' + 10; |
| else |
| return -1; |
| |
| return 0; |
| } |
| |
| /* Filenames are hex encoded, so the maximum we can handle is half the |
| packet buffer size. Cap to PATH_MAX, if it is shorter. */ |
| #if !defined (PATH_MAX) || (PATH_MAX > (PBUFSIZ / 2 + 1)) |
| # define HOSTIO_PATH_MAX (PBUFSIZ / 2 + 1) |
| #else |
| # define HOSTIO_PATH_MAX PATH_MAX |
| #endif |
| |
| static int |
| require_filename (char **pp, char *filename) |
| { |
| int count; |
| char *p; |
| |
| p = *pp; |
| count = 0; |
| |
| while (*p && *p != ',') |
| { |
| int nib1, nib2; |
| |
| /* Don't allow overflow. */ |
| if (count >= HOSTIO_PATH_MAX - 1) |
| return -1; |
| |
| if (safe_fromhex (p[0], &nib1) |
| || safe_fromhex (p[1], &nib2)) |
| return -1; |
| |
| filename[count++] = nib1 * 16 + nib2; |
| p += 2; |
| } |
| |
| filename[count] = '\0'; |
| *pp = p; |
| return 0; |
| } |
| |
| static int |
| require_int (char **pp, int *value) |
| { |
| char *p; |
| int count, firstdigit; |
| |
| p = *pp; |
| *value = 0; |
| count = 0; |
| firstdigit = -1; |
| |
| while (*p && *p != ',') |
| { |
| int nib; |
| |
| if (safe_fromhex (p[0], &nib)) |
| return -1; |
| |
| if (firstdigit == -1) |
| firstdigit = nib; |
| |
| /* Don't allow overflow. */ |
| if (count >= 8 || (count == 7 && firstdigit >= 0x8)) |
| return -1; |
| |
| *value = *value * 16 + nib; |
| p++; |
| count++; |
| } |
| |
| *pp = p; |
| return 0; |
| } |
| |
| static int |
| require_data (char *p, int p_len, char **data, int *data_len) |
| { |
| int input_index, output_index, escaped; |
| |
| *data = (char *) xmalloc (p_len); |
| |
| output_index = 0; |
| escaped = 0; |
| for (input_index = 0; input_index < p_len; input_index++) |
| { |
| char b = p[input_index]; |
| |
| if (escaped) |
| { |
| (*data)[output_index++] = b ^ 0x20; |
| escaped = 0; |
| } |
| else if (b == '}') |
| escaped = 1; |
| else |
| (*data)[output_index++] = b; |
| } |
| |
| if (escaped) |
| { |
| free (*data); |
| return -1; |
| } |
| |
| *data_len = output_index; |
| return 0; |
| } |
| |
| static int |
| require_comma (char **pp) |
| { |
| if (**pp == ',') |
| { |
| (*pp)++; |
| return 0; |
| } |
| else |
| return -1; |
| } |
| |
| static int |
| require_end (char *p) |
| { |
| if (*p == '\0') |
| return 0; |
| else |
| return -1; |
| } |
| |
| static int |
| require_valid_fd (int fd) |
| { |
| struct fd_list *fd_ptr; |
| |
| for (fd_ptr = open_fds; fd_ptr != NULL; fd_ptr = fd_ptr->next) |
| if (fd_ptr->fd == fd) |
| return 0; |
| |
| return -1; |
| } |
| |
| /* Fill BUF with an hostio error packet representing the last hostio |
| error, from errno. */ |
| |
| static void |
| hostio_error (char *own_buf) |
| { |
| int fileio_error = host_to_fileio_error (errno); |
| sprintf (own_buf, "F-1,%x", fileio_error); |
| } |
| |
| static void |
| hostio_packet_error (char *own_buf) |
| { |
| sprintf (own_buf, "F-1,%x", FILEIO_EINVAL); |
| } |
| |
| static void |
| hostio_reply (char *own_buf, int result) |
| { |
| sprintf (own_buf, "F%x", result); |
| } |
| |
| static int |
| hostio_reply_with_data (char *own_buf, char *buffer, int len, |
| int *new_packet_len) |
| { |
| int input_index, output_index, out_maxlen; |
| |
| sprintf (own_buf, "F%x;", len); |
| output_index = strlen (own_buf); |
| |
| out_maxlen = PBUFSIZ; |
| |
| for (input_index = 0; input_index < len; input_index++) |
| { |
| char b = buffer[input_index]; |
| |
| if (b == '$' || b == '#' || b == '}' || b == '*') |
| { |
| /* These must be escaped. */ |
| if (output_index + 2 > out_maxlen) |
| break; |
| own_buf[output_index++] = '}'; |
| own_buf[output_index++] = b ^ 0x20; |
| } |
| else |
| { |
| if (output_index + 1 > out_maxlen) |
| break; |
| own_buf[output_index++] = b; |
| } |
| } |
| |
| *new_packet_len = output_index; |
| return input_index; |
| } |
| |
| /* Process ID of inferior whose filesystem hostio functions |
| that take FILENAME arguments will use. Zero means to use |
| our own filesystem. */ |
| |
| static int hostio_fs_pid; |
| |
| /* See hostio.h. */ |
| |
| void |
| hostio_handle_new_gdb_connection (void) |
| { |
| hostio_fs_pid = 0; |
| } |
| |
| /* Handle a "vFile:setfs:" packet. */ |
| |
| static void |
| handle_setfs (char *own_buf) |
| { |
| char *p; |
| int pid; |
| |
| /* If the target doesn't have any of the in-filesystem-of methods |
| then there's no point in GDB sending "vFile:setfs:" packets. We |
| reply with an empty packet (i.e. we pretend we don't understand |
| "vFile:setfs:") and that should stop GDB sending any more. */ |
| if (!the_target->supports_multifs ()) |
| { |
| own_buf[0] = '\0'; |
| return; |
| } |
| |
| p = own_buf + strlen ("vFile:setfs:"); |
| |
| if (require_int (&p, &pid) |
| || pid < 0 |
| || require_end (p)) |
| { |
| hostio_packet_error (own_buf); |
| return; |
| } |
| |
| hostio_fs_pid = pid; |
| |
| hostio_reply (own_buf, 0); |
| } |
| |
| static void |
| handle_open (char *own_buf) |
| { |
| char filename[HOSTIO_PATH_MAX]; |
| char *p; |
| int fileio_flags, fileio_mode, flags, fd; |
| mode_t mode; |
| struct fd_list *new_fd; |
| |
| p = own_buf + strlen ("vFile:open:"); |
| |
| if (require_filename (&p, filename) |
| || require_comma (&p) |
| || require_int (&p, &fileio_flags) |
| || require_comma (&p) |
| || require_int (&p, &fileio_mode) |
| || require_end (p) |
| || fileio_to_host_openflags (fileio_flags, &flags) |
| || fileio_to_host_mode (fileio_mode, &mode)) |
| { |
| hostio_packet_error (own_buf); |
| return; |
| } |
| |
| /* We do not need to convert MODE, since the fileio protocol |
| uses the standard values. */ |
| if (hostio_fs_pid != 0) |
| fd = the_target->multifs_open (hostio_fs_pid, filename, flags, mode); |
| else |
| fd = open (filename, flags, mode); |
| |
| if (fd == -1) |
| { |
| hostio_error (own_buf); |
| return; |
| } |
| |
| /* Record the new file descriptor. */ |
| new_fd = XNEW (struct fd_list); |
| new_fd->fd = fd; |
| new_fd->next = open_fds; |
| open_fds = new_fd; |
| |
| hostio_reply (own_buf, fd); |
| } |
| |
| static void |
| handle_pread (char *own_buf, int *new_packet_len) |
| { |
| int fd, ret, len, offset, bytes_sent; |
| char *p, *data; |
| static int max_reply_size = -1; |
| |
| p = own_buf + strlen ("vFile:pread:"); |
| |
| if (require_int (&p, &fd) |
| || require_comma (&p) |
| || require_valid_fd (fd) |
| || require_int (&p, &len) |
| || require_comma (&p) |
| || require_int (&p, &offset) |
| || require_end (p)) |
| { |
| hostio_packet_error (own_buf); |
| return; |
| } |
| |
| /* Do not attempt to read more than the maximum number of bytes |
| hostio_reply_with_data can fit in a packet. We may still read |
| too much because of escaping, but this is handled below. */ |
| if (max_reply_size == -1) |
| { |
| sprintf (own_buf, "F%x;", PBUFSIZ); |
| max_reply_size = PBUFSIZ - strlen (own_buf); |
| } |
| if (len > max_reply_size) |
| len = max_reply_size; |
| |
| data = (char *) xmalloc (len); |
| #ifdef HAVE_PREAD |
| ret = pread (fd, data, len, offset); |
| #else |
| ret = -1; |
| #endif |
| /* If we have no pread or it failed for this file, use lseek/read. */ |
| if (ret == -1) |
| { |
| ret = lseek (fd, offset, SEEK_SET); |
| if (ret != -1) |
| ret = read (fd, data, len); |
| } |
| |
| if (ret == -1) |
| { |
| hostio_error (own_buf); |
| free (data); |
| return; |
| } |
| |
| bytes_sent = hostio_reply_with_data (own_buf, data, ret, new_packet_len); |
| |
| /* If we were using read, and the data did not all fit in the reply, |
| we would have to back up using lseek here. With pread it does |
| not matter. But we still have a problem; the return value in the |
| packet might be wrong, so we must fix it. This time it will |
| definitely fit. */ |
| if (bytes_sent < ret) |
| bytes_sent = hostio_reply_with_data (own_buf, data, bytes_sent, |
| new_packet_len); |
| |
| free (data); |
| } |
| |
| static void |
| handle_pwrite (char *own_buf, int packet_len) |
| { |
| int fd, ret, len, offset; |
| char *p, *data; |
| |
| p = own_buf + strlen ("vFile:pwrite:"); |
| |
| if (require_int (&p, &fd) |
| || require_comma (&p) |
| || require_valid_fd (fd) |
| || require_int (&p, &offset) |
| || require_comma (&p) |
| || require_data (p, packet_len - (p - own_buf), &data, &len)) |
| { |
| hostio_packet_error (own_buf); |
| return; |
| } |
| |
| #ifdef HAVE_PWRITE |
| ret = pwrite (fd, data, len, offset); |
| #else |
| ret = -1; |
| #endif |
| /* If we have no pwrite or it failed for this file, use lseek/write. */ |
| if (ret == -1) |
| { |
| ret = lseek (fd, offset, SEEK_SET); |
| if (ret != -1) |
| ret = write (fd, data, len); |
| } |
| |
| if (ret == -1) |
| { |
| hostio_error (own_buf); |
| free (data); |
| return; |
| } |
| |
| hostio_reply (own_buf, ret); |
| free (data); |
| } |
| |
| static void |
| handle_fstat (char *own_buf, int *new_packet_len) |
| { |
| int fd, bytes_sent; |
| char *p; |
| struct stat st; |
| struct fio_stat fst; |
| |
| p = own_buf + strlen ("vFile:fstat:"); |
| |
| if (require_int (&p, &fd) |
| || require_valid_fd (fd) |
| || require_end (p)) |
| { |
| hostio_packet_error (own_buf); |
| return; |
| } |
| |
| if (fstat (fd, &st) == -1) |
| { |
| hostio_error (own_buf); |
| return; |
| } |
| |
| host_to_fileio_stat (&st, &fst); |
| |
| bytes_sent = hostio_reply_with_data (own_buf, |
| (char *) &fst, sizeof (fst), |
| new_packet_len); |
| |
| /* If the response does not fit into a single packet, do not attempt |
| to return a partial response, but simply fail. */ |
| if (bytes_sent < sizeof (fst)) |
| write_enn (own_buf); |
| } |
| |
| static void |
| handle_stat (char *own_buf, int *new_packet_len) |
| { |
| int bytes_sent; |
| char *p; |
| struct stat st; |
| struct fio_stat fst; |
| char filename[HOSTIO_PATH_MAX]; |
| |
| p = own_buf + strlen ("vFile:stat:"); |
| |
| if (require_filename (&p, filename) |
| || require_end (p)) |
| { |
| hostio_packet_error (own_buf); |
| return; |
| } |
| |
| if (lstat (filename, &st) == -1) |
| { |
| hostio_error (own_buf); |
| return; |
| } |
| |
| host_to_fileio_stat (&st, &fst); |
| |
| bytes_sent = hostio_reply_with_data (own_buf, |
| (char *) &fst, sizeof (fst), |
| new_packet_len); |
| |
| /* If the response does not fit into a single packet, do not attempt |
| to return a partial response, but simply fail. */ |
| if (bytes_sent < sizeof (fst)) |
| write_enn (own_buf); |
| } |
| |
| static void |
| handle_close (char *own_buf) |
| { |
| int fd, ret; |
| char *p; |
| struct fd_list **open_fd_p, *old_fd; |
| |
| p = own_buf + strlen ("vFile:close:"); |
| |
| if (require_int (&p, &fd) |
| || require_valid_fd (fd) |
| || require_end (p)) |
| { |
| hostio_packet_error (own_buf); |
| return; |
| } |
| |
| ret = close (fd); |
| |
| if (ret == -1) |
| { |
| hostio_error (own_buf); |
| return; |
| } |
| |
| open_fd_p = &open_fds; |
| /* We know that fd is in the list, thanks to require_valid_fd. */ |
| while ((*open_fd_p)->fd != fd) |
| open_fd_p = &(*open_fd_p)->next; |
| |
| old_fd = *open_fd_p; |
| *open_fd_p = (*open_fd_p)->next; |
| free (old_fd); |
| |
| hostio_reply (own_buf, ret); |
| } |
| |
| static void |
| handle_unlink (char *own_buf) |
| { |
| char filename[HOSTIO_PATH_MAX]; |
| char *p; |
| int ret; |
| |
| p = own_buf + strlen ("vFile:unlink:"); |
| |
| if (require_filename (&p, filename) |
| || require_end (p)) |
| { |
| hostio_packet_error (own_buf); |
| return; |
| } |
| |
| if (hostio_fs_pid != 0) |
| ret = the_target->multifs_unlink (hostio_fs_pid, filename); |
| else |
| ret = unlink (filename); |
| |
| if (ret == -1) |
| { |
| hostio_error (own_buf); |
| return; |
| } |
| |
| hostio_reply (own_buf, ret); |
| } |
| |
| static void |
| handle_readlink (char *own_buf, int *new_packet_len) |
| { |
| char filename[HOSTIO_PATH_MAX], linkname[HOSTIO_PATH_MAX]; |
| char *p; |
| int ret, bytes_sent; |
| |
| p = own_buf + strlen ("vFile:readlink:"); |
| |
| if (require_filename (&p, filename) |
| || require_end (p)) |
| { |
| hostio_packet_error (own_buf); |
| return; |
| } |
| |
| if (hostio_fs_pid != 0) |
| ret = the_target->multifs_readlink (hostio_fs_pid, filename, |
| linkname, |
| sizeof (linkname) - 1); |
| else |
| ret = readlink (filename, linkname, sizeof (linkname) - 1); |
| |
| if (ret == -1) |
| { |
| hostio_error (own_buf); |
| return; |
| } |
| |
| bytes_sent = hostio_reply_with_data (own_buf, linkname, ret, new_packet_len); |
| |
| /* If the response does not fit into a single packet, do not attempt |
| to return a partial response, but simply fail. */ |
| if (bytes_sent < ret) |
| sprintf (own_buf, "F-1,%x", FILEIO_ENAMETOOLONG); |
| } |
| |
| /* Handle all the 'F' file transfer packets. */ |
| |
| int |
| handle_vFile (char *own_buf, int packet_len, int *new_packet_len) |
| { |
| if (startswith (own_buf, "vFile:open:")) |
| handle_open (own_buf); |
| else if (startswith (own_buf, "vFile:pread:")) |
| handle_pread (own_buf, new_packet_len); |
| else if (startswith (own_buf, "vFile:pwrite:")) |
| handle_pwrite (own_buf, packet_len); |
| else if (startswith (own_buf, "vFile:fstat:")) |
| handle_fstat (own_buf, new_packet_len); |
| else if (startswith (own_buf, "vFile:stat:")) |
| handle_stat (own_buf, new_packet_len); |
| else if (startswith (own_buf, "vFile:close:")) |
| handle_close (own_buf); |
| else if (startswith (own_buf, "vFile:unlink:")) |
| handle_unlink (own_buf); |
| else if (startswith (own_buf, "vFile:readlink:")) |
| handle_readlink (own_buf, new_packet_len); |
| else if (startswith (own_buf, "vFile:setfs:")) |
| handle_setfs (own_buf); |
| else |
| return 0; |
| |
| return 1; |
| } |