On Thu, Jan 31, 2019 at 03:03:21PM -0600, Eric Blake wrote: > On 1/31/19 2:26 PM, Julia Suvorova via Qemu-devel wrote: > > The whitelist option allows to run a reduced monitor with a subset of > > QMP commands. This allows the monitor to run in secure mode, which is > > convenient for sending commands via the WebSocket monitor using the > > web UI. This is planned to be done on micro:bit board. > > > > The list of allowed commands should be written to a file, one per line. > > The command line will look like this: > > -mon chardev_name,mode=control,whitelist=path_to_file > > > > Signed-off-by: Julia Suvorova <jus...@mail.ru> > > --- > > > > > -void monitor_init(Chardev *chr, int flags) > > +static void process_whitelist_file(Monitor *mon, const char > > *whitelist_file) > > +{ > > + char cmd_name[256]; > > + FILE *fd = fopen(whitelist_file, "r"); > > If you use qemu_open() here (followed by fdopen if you still prefer > fscanf over read), then you can support "/dev/fdset/NNN" to > auto-magically support someone passing in the whitelist via an inherited > file descriptor, rather than having to be somewhere on disk that qemu > can directly open(). > > > + > > + if (fd == NULL) { > > + error_report("Could not open whitelist file: %s", strerror(errno)); > > + exit(1); > > + } > > + > > + mon->whitelist = g_hash_table_new_full(g_str_hash, > > + g_str_equal, > > + g_free, > > + NULL); > > + > > + g_hash_table_add(mon->whitelist, g_strdup("qmp_capabilities")); > > + g_hash_table_add(mon->whitelist, g_strdup("query-commands")); > > + > > + while (fscanf(fd, "%255s", cmd_name) == 1) { > > %255s fits your cmd_name array declaration and stops consuming at either > 255 bytes or at the first whitespace encountered, but where do you check > for overflow from a file that passes more than 255 non-whitespace bytes > without a newline? Also, this is a bit sloppy in that it skips all > leading whitespace, rather than ensuring that the user actually passed > newline-separated command names. Does glib provide any interfaces for > more easily reading in an array of lines from a file?
With glib, normally you'd use: char *content; gsize len; GError *err = NULL; char **lines; g_file_get_contents(filename, &contnet, &len, &err) lines = g_str_split(content, "\n", 0); g_free(content); ...do something with lines g_strfreev(lines); The GIO library provides higher level functions for I/O but we don't use that in QEMU Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|