diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/internals.rs | 167 | ||||
| -rw-r--r-- | src/lib.rs | 735 |
2 files changed, 727 insertions, 175 deletions
diff --git a/src/internals.rs b/src/internals.rs index 8a881e0..71ac93f 100644 --- a/src/internals.rs +++ b/src/internals.rs @@ -19,6 +19,7 @@ //! //! This also includes the hexchat_plugin struct, from hexchat-plugin.h. Note that we use the //! struct even on non-Windows platforms because it's a lot easier that way. Should be safe, tho. + use libc; // apparently this is the right way to do these @@ -54,85 +55,85 @@ pub type HexchatPlugin = Ph; #[repr(C)] pub struct Ph { - pub hexchat_hook_command: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + pub hexchat_hook_command: unsafe extern "C" fn(ph: *mut HexchatPlugin, name: *const libc::c_char, pri: libc::c_int, /* CALLBACK */ - callback: Option<unsafe extern "C" fn(word: *const *const libc::c_char, word_eol: *const *const libc::c_char, user_data: *mut libc::c_void) -> libc::c_int>, + callback: unsafe extern "C" fn(word: *const *const libc::c_char, word_eol: *const *const libc::c_char, user_data: *mut libc::c_void) -> libc::c_int, help_text: *const libc::c_char, - userdata: *mut libc::c_void) -> *const HexchatHook>, - pub hexchat_hook_server: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + userdata: *mut libc::c_void) -> *const HexchatHook, + pub hexchat_hook_server: unsafe extern "C" fn(ph: *mut HexchatPlugin, name: *const libc::c_char, pri: libc::c_int, /* CALLBACK */ callback: Option<unsafe extern "C" fn(word: *const *const libc::c_char, word_eol: *const *const libc::c_char, user_data: *mut libc::c_void) -> libc::c_int>, - userdata: *mut libc::c_void) -> *const HexchatHook>, - pub hexchat_hook_print: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + userdata: *mut libc::c_void) -> *const HexchatHook, + pub hexchat_hook_print: unsafe extern "C" fn(ph: *mut HexchatPlugin, name: *const libc::c_char, pri: libc::c_int, /* CALLBACK */ callback: Option<unsafe extern "C" fn(word: *const *const libc::c_char, user_data: *mut libc::c_void) -> libc::c_int>, - userdata: *mut libc::c_void) -> *const HexchatHook>, - pub hexchat_hook_timer: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + userdata: *mut libc::c_void) -> *const HexchatHook, + pub hexchat_hook_timer: unsafe extern "C" fn(ph: *mut HexchatPlugin, timeout: libc::c_int, /* CALLBACK */ callback: Option<unsafe extern "C" fn(user_data: *mut libc::c_void) -> libc::c_int>, - userdata: *mut libc::c_void) -> *const HexchatHook>, - pub hexchat_hook_fd: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + userdata: *mut libc::c_void) -> *const HexchatHook, + pub hexchat_hook_fd: unsafe extern "C" fn(ph: *mut HexchatPlugin, fd: libc::c_int, flags: libc::c_int, /* CALLBACK */ callback: Option<unsafe extern "C" fn(fd: libc::c_int, flags: libc::c_int, user_data: *mut libc::c_void) -> libc::c_int>, - userdata: *mut libc::c_void) -> *const HexchatHook>, - pub hexchat_unhook: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - hook: *const HexchatHook) -> *const libc::c_void>, - pub hexchat_print: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - text: *const libc::c_char)>, - pub hexchat_printf: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - format: *const libc::c_char, ...)>, - pub hexchat_command: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - command: *const libc::c_char)>, - pub hexchat_commandf: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - format: *const libc::c_char, ...)>, - pub hexchat_nickcmp: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + userdata: *mut libc::c_void) -> *const HexchatHook, + pub hexchat_unhook: unsafe extern "C" fn(ph: *mut HexchatPlugin, + hook: *const HexchatHook) -> *const libc::c_void, + pub hexchat_print: unsafe extern "C" fn(ph: *mut HexchatPlugin, + text: *const libc::c_char), + pub hexchat_printf_do_not_use: unsafe extern "C" fn(ph: *mut HexchatPlugin, + format: *const libc::c_char, ...), + pub hexchat_command: unsafe extern "C" fn(ph: *mut HexchatPlugin, + command: *const libc::c_char), + pub hexchat_commandf_do_not_use: unsafe extern "C" fn(ph: *mut HexchatPlugin, + format: *const libc::c_char, ...), + pub hexchat_nickcmp: unsafe extern "C" fn(ph: *mut HexchatPlugin, s1: *const libc::c_char, - s2: *const libc::c_char) -> libc::c_int>, - pub hexchat_set_context: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - ctx: *const HexchatContext) -> libc::c_int>, - pub hexchat_find_context: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + s2: *const libc::c_char) -> libc::c_int, + pub hexchat_set_context: unsafe extern "C" fn(ph: *mut HexchatPlugin, + ctx: *const HexchatContext) -> libc::c_int, + pub hexchat_find_context: unsafe extern "C" fn(ph: *mut HexchatPlugin, servname: *const libc::c_char, - channel: *const libc::c_char) -> *const HexchatContext>, - pub hexchat_get_context: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin) -> *const HexchatContext>, - pub hexchat_get_info: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - id: *const libc::c_char) -> *const libc::c_char>, - pub hexchat_get_prefs: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + channel: *const libc::c_char) -> *const HexchatContext, + pub hexchat_get_context: unsafe extern "C" fn(ph: *mut HexchatPlugin) -> *const HexchatContext, + pub hexchat_get_info: unsafe extern "C" fn(ph: *mut HexchatPlugin, + id: *const libc::c_char) -> *const libc::c_char, + pub hexchat_get_prefs: unsafe extern "C" fn(ph: *mut HexchatPlugin, name: *const libc::c_char, string: *mut *const libc::c_char, - integer: *mut libc::c_int) -> libc::c_int>, - pub hexchat_list_get: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - name: *const libc::c_char) -> *const HexchatList>, - pub hexchat_list_free: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - xlist: *const HexchatList)>, - pub hexchat_list_fields: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - name: *const libc::c_char) -> *const *const libc::c_char>, - pub hexchat_list_next: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - xlist: *const HexchatList) -> libc::c_int>, - pub hexchat_list_str: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + integer: *mut libc::c_int) -> libc::c_int, + pub hexchat_list_get: unsafe extern "C" fn(ph: *mut HexchatPlugin, + name: *const libc::c_char) -> *const HexchatList, + pub hexchat_list_free: unsafe extern "C" fn(ph: *mut HexchatPlugin, + xlist: *const HexchatList), + pub hexchat_list_fields: unsafe extern "C" fn(ph: *mut HexchatPlugin, + name: *const libc::c_char) -> *const *const libc::c_char, + pub hexchat_list_next: unsafe extern "C" fn(ph: *mut HexchatPlugin, + xlist: *const HexchatList) -> libc::c_int, + pub hexchat_list_str: unsafe extern "C" fn(ph: *mut HexchatPlugin, xlist: *const HexchatList, - name: *const libc::c_char) -> *const libc::c_char>, - pub hexchat_list_int: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + name: *const libc::c_char) -> *const libc::c_char, + pub hexchat_list_int: unsafe extern "C" fn(ph: *mut HexchatPlugin, xlist: *const HexchatList, - name: *const libc::c_char) -> libc::c_int>, - pub hexchat_plugingui_add: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + name: *const libc::c_char) -> libc::c_int, + pub hexchat_plugingui_add: unsafe extern "C" fn(ph: *mut HexchatPlugin, filename: *const libc::c_char, name: *const libc::c_char, desc: *const libc::c_char, version: *const libc::c_char, - reserved: *mut char) -> *const PluginGuiHandle>, - pub hexchat_plugingui_remove: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - handle: *const PluginGuiHandle)>, - pub hexchat_emit_print: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - event_name: *const libc::c_char, ...) -> libc::c_int>, + reserved: *mut char) -> *const PluginGuiHandle, + pub hexchat_plugingui_remove: unsafe extern "C" fn(ph: *mut HexchatPlugin, + handle: *const PluginGuiHandle), + pub hexchat_emit_print: unsafe extern "C" fn(ph: *mut HexchatPlugin, + event_name: *const libc::c_char, ...) -> libc::c_int, // this is VERY NAUGHTY. // TODO see if hexchat's gonna provide a proper userdata field at some point. // it appears this function isn't used anywhere by hexchat so we reuse its pointer. @@ -140,57 +141,57 @@ pub struct Ph { // another option would've been to use one of the printf functions. // TODO test this on platforms hexchat doesn't build on, like AVR. pub userdata: *mut libc::c_void, - /*pub hexchat_read_fd: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + /*pub hexchat_read_fd: unsafe extern "C" fn(ph: *mut HexchatPlugin, src: *const libc::c_void, buf: *mut char, - len: *mut libc::c_int) -> libc::c_int>,*/ - pub hexchat_list_time: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + len: *mut libc::c_int) -> libc::c_int,*/ + pub hexchat_list_time: unsafe extern "C" fn(ph: *mut HexchatPlugin, xlist: *const HexchatList, - name: *const libc::c_char) -> libc::time_t>, - pub hexchat_gettext: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - msgid: *const libc::c_char) -> *const libc::c_char>, - pub hexchat_send_modes: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + name: *const libc::c_char) -> libc::time_t, + pub hexchat_gettext: unsafe extern "C" fn(ph: *mut HexchatPlugin, + msgid: *const libc::c_char) -> *const libc::c_char, + pub hexchat_send_modes: unsafe extern "C" fn(ph: *mut HexchatPlugin, targets: *mut *const libc::c_char, ntargets: libc::c_int, modes_per_line: libc::c_int, sign: libc::c_char, - mode: libc::c_char)>, - pub hexchat_strip: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + mode: libc::c_char), + pub hexchat_strip: unsafe extern "C" fn(ph: *mut HexchatPlugin, string: *const libc::c_char, len: libc::c_int, - flags: libc::c_int) -> *const libc::c_char>, - pub hexchat_free: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - ptr: *const libc::c_void)>, - pub hexchat_pluginpref_set_str: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + flags: libc::c_int) -> *const libc::c_char, + pub hexchat_free: unsafe extern "C" fn(ph: *mut HexchatPlugin, + ptr: *const libc::c_void), + pub hexchat_pluginpref_set_str: unsafe extern "C" fn(ph: *mut HexchatPlugin, var: *const libc::c_char, - value: *const libc::c_char) -> libc::c_int>, - pub hexchat_pluginpref_get_str: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + value: *const libc::c_char) -> libc::c_int, + pub hexchat_pluginpref_get_str: unsafe extern "C" fn(ph: *mut HexchatPlugin, var: *const libc::c_char, - dest: *mut char) -> libc::c_int>, - pub hexchat_pluginpref_set_int: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + dest: *mut char) -> libc::c_int, + pub hexchat_pluginpref_set_int: unsafe extern "C" fn(ph: *mut HexchatPlugin, var: *const libc::c_char, - value: libc::c_int) -> libc::c_int>, - pub hexchat_pluginpref_get_int: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - var: *const libc::c_char) -> libc::c_int>, - pub hexchat_pluginpref_delete: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - var: *const libc::c_char) -> libc::c_int>, - pub hexchat_pluginpref_list: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - dest: *mut char) -> libc::c_int>, - pub hexchat_hook_server_attrs: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + value: libc::c_int) -> libc::c_int, + pub hexchat_pluginpref_get_int: unsafe extern "C" fn(ph: *mut HexchatPlugin, + var: *const libc::c_char) -> libc::c_int, + pub hexchat_pluginpref_delete: unsafe extern "C" fn(ph: *mut HexchatPlugin, + var: *const libc::c_char) -> libc::c_int, + pub hexchat_pluginpref_list: unsafe extern "C" fn(ph: *mut HexchatPlugin, + dest: *mut char) -> libc::c_int, + pub hexchat_hook_server_attrs: unsafe extern "C" fn(ph: *mut HexchatPlugin, name: *const libc::c_char, pri: libc::c_int, /* CALLBACK */ callback: Option<unsafe extern "C" fn(word: *const *const libc::c_char, word_eol: *const *const libc::c_char, attrs: *const HexchatEventAttrs, user_data: *mut libc::c_void) -> libc::c_int>, - userdata: *mut libc::c_void) -> *const HexchatHook>, - pub hexchat_hook_print_attrs: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, + userdata: *mut libc::c_void) -> *const HexchatHook, + pub hexchat_hook_print_attrs: unsafe extern "C" fn(ph: *mut HexchatPlugin, name: *const libc::c_char, pri: libc::c_int, /* CALLBACK */ callback: Option<unsafe extern "C" fn(word: *const *const libc::c_char, attrs: *const HexchatEventAttrs, user_data: *mut libc::c_void) -> libc::c_int>, - userdata: *mut libc::c_void) -> *const HexchatHook>, - pub hexchat_emit_print_attrs: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, attrs: *const HexchatEventAttrs, - event_name: *const libc::c_char, ...) -> libc::c_int>, - pub hexchat_event_attrs_create: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin) -> *mut HexchatEventAttrs>, - pub hexchat_event_attrs_free: Option<unsafe extern "C" fn(ph: *mut HexchatPlugin, - attrs: *const HexchatEventAttrs)>, + userdata: *mut libc::c_void) -> *const HexchatHook, + pub hexchat_emit_print_attrs: unsafe extern "C" fn(ph: *mut HexchatPlugin, attrs: *const HexchatEventAttrs, + event_name: *const libc::c_char, ...) -> libc::c_int, + pub hexchat_event_attrs_create: unsafe extern "C" fn(ph: *mut HexchatPlugin) -> *mut HexchatEventAttrs, + pub hexchat_event_attrs_free: unsafe extern "C" fn(ph: *mut HexchatPlugin, + attrs: *const HexchatEventAttrs), } diff --git a/src/lib.rs b/src/lib.rs index 85fe77f..1399448 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -17,6 +17,62 @@ */ //! <!-- TODO (placeholder) --> +/* + * Some info about how HexChat does things: + * + * All strings passed across the C API are UTF-8. + * - Except `hexchat_get_info(ph, "libdirfs")`, so we need to be careful with that one. + * + * The pointers `name: *mut *const char, desc: *mut *const char, vers: *mut *const char` point to + * inside the ph - that is, they're aliased. Thus, we must never convert a ph to an & or &mut + * except as part of retrieving or setting values in it (e.g. `(*ph).hexchat_get_info` or + * `(*ph).userdata = value`). + * + * `hexchat_plugin_get_info` is never used, so we omit it. It would be impractical not to. + * + * These cause UB: + * `hexchat_command` may invalidate the plugin context. + * `hexchat_find_context` and `hexchat_nickcmp` use the plugin context without checking it. + * `hexchat_get_prefs` uses the plugin context if name == "state_cursor" or "id" (or anything with + * the same hash). + * `hexchat_list_get` uses the plugin context if name == "notify" (or anything with the same hash). + * `hexchat_list_str`, `hexchat_list_int`, + * `hexchat_emit_print`, `hexchat_emit_print_attrs` use the plugin context. + * `hexchat_send_modes` uses the plugin context. + * We need to wrap them (or, alternatively, hexchat_command). However, there's no (safe) way to get + * a valid context afterwards. + * - Actually that's a lie. Hexchat does a trick to give you a context as part of the channel list. + * We can use that to our advantage. I'm not sure if it's better to wrap hexchat_command or the + * other functions, tho. + * (Do we want to walk a linked list every time we use hexchat_command? I'd think + * hexchat_command is the most used API function... Plus, emit_print could indirectly + * invalidate the context as well.) + * + * `hexchat_send_modes` should only be used with channels; however, it doesn't cause UB - it just + * doesn't work. + * + * `hexchat_pluginpref_get_int`, `hexchat_pluginpref_get_str`, `hexchat_pluginpref_set_int`, + * `hexchat_pluginpref_set_str` cannot be used while `name`, `desc`, `vers` are null. + * + * `hexchat_plugin_init` receives an arg string. it may be null. this isn't documented anywhere. + */ + +/* + * Some info about how we do things: + * + * DO NOT CALL printf/commandf/etc FAMILY OF FUNCTIONS. You can't avoid allocations, so just + * allocate some CStrings on the Rust side. It has the exact same effect, since those functions + * allocate internally anyway. + */ + +/* + * Big list o' TODO: + * -[ ] Finish basic API support. [PRI-HIGH] + * -[ ] Wrap contexts within something we keep track of. Mark them invalid when contexts are + * closed. [PRI-MAYBE] + * -[ ] ??? + */ + #[doc(hidden)] pub extern crate libc; @@ -26,152 +82,647 @@ use std::panic::catch_unwind; use std::thread; use std::ffi::{CString, CStr}; use std::str::FromStr; +use std::mem; +use std::ptr; +use std::marker::PhantomData; +use std::ops; -const EMPTY_CSTRING_DATA: &[u8] = b"\0"; +// ****** // +// PUBLIC // +// ****** // /// A hexchat plugin pub trait Plugin { - fn init(&mut self, &mut PluginHandle) -> bool; + /// Called to initialize the plugin. + fn init(&self, ph: &mut PluginHandle, arg: Option<&str>) -> bool; + + /// Called to deinitialize the plugin. + /// + /// This is always called immediately prior to Drop::drop. + fn deinit(&self, _ph: &mut PluginHandle) { + } } -/// A handle for a hexchat plugin +/// A hexchat plugin handle pub struct PluginHandle { ph: *mut internals::Ph, - filename: Option<CString>, - registered: bool, - fakehandle: *const internals::PluginGuiHandle, + // Used for registration + info: PluginInfo, +} + +pub struct Word<'a> { + word: Vec<&'a str> +} + +pub struct WordEol<'a> { + word_eol: Vec<&'a str> +} + +/// A safety wrapper that ensures you're working with a valid context. +pub struct EnsureValidContext<'a> { + ph: &'a mut PluginHandle, +} + +/// An status indicator for event callbacks. Indicates whether to continue processing, eat hexchat, +/// eat plugin, or eat all. +#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)] +pub struct Eat { + do_eat: i32, +} + +/// Equivalent to HEXCHAT_EAT_NONE. +pub const EAT_NONE: Eat = Eat { do_eat: 0 }; +/// Equivalent to HEXCHAT_EAT_HEXCHAT. +pub const EAT_HEXCHAT: Eat = Eat { do_eat: 1 }; +/// Equivalent to HEXCHAT_EAT_PLUGIN. +pub const EAT_PLUGIN: Eat = Eat { do_eat: 2 }; +/// Equivalent to HEXCHAT_EAT_ALL. +pub const EAT_ALL: Eat = Eat { do_eat: 1 | 2 }; + +/// A command hook handle, created with PluginHandle::hook_command. +pub struct CommandHookHandle { + ph: *mut internals::Ph, + hh: *const internals::HexchatHook, + // this does actually store an Box<...>, but on the other side of the FFI. + _f: PhantomData<Box<CommandHookUd>>, +} + +/// A context. +// We don't want this Copy + Clone, as we may want to implement a context invalidation system +// at some point (rather than relying on the hexchat allocator not to allocate a new context where +// a context was free'd). +pub struct Context { + ctx: *const internals::HexchatContext, +} + +// #[derive(Debug)] // doesn't work +pub struct InvalidContextError<F: FnOnce(EnsureValidContext) -> R, R>(F); + +impl<F: FnOnce(EnsureValidContext) -> R, R> InvalidContextError<F, R> { + pub fn get_closure(self) -> F { + self.0 + } +} + +impl Drop for CommandHookHandle { + fn drop(&mut self) { + unsafe { + let b = ((*self.ph).hexchat_unhook)(self.ph, self.hh) as *mut CommandHookUd; + // we assume b is not null. this should be safe. + // just drop it + mem::drop(Box::from_raw(b)); + } + } +} + +impl<'a> Word<'a> { + unsafe fn new(word: *const *const libc::c_char) -> Word<'a> { + let mut vec = vec![]; + for i in 1..32 { + let w = *word.offset(i); + if !w.is_null() { + vec.push(CStr::from_ptr(w).to_str().expect("non-utf8 word - broken hexchat")) + } else { + break + } + } + Word { word: vec } + } +} + +impl<'a> ops::Deref for Word<'a> { + type Target = [&'a str]; + fn deref(&self) -> &[&'a str] { + &self.word + } +} + +impl<'a> WordEol<'a> { + unsafe fn new(word_eol: *const *const libc::c_char) -> WordEol<'a> { + let mut vec = vec![]; + for i in 1..32 { + let w = *word_eol.offset(i); + if !w.is_null() { + vec.push(CStr::from_ptr(w).to_str().expect("non-utf8 word_eol - broken hexchat")) + } else { + break + } + } + WordEol { word_eol: vec } + } +} + +impl<'a> ops::Deref for WordEol<'a> { + type Target = [&'a str]; + fn deref(&self) -> &[&'a str] { + &self.word_eol + } } impl PluginHandle { + fn new(ph: *mut internals::Ph, info: PluginInfo) -> PluginHandle { + PluginHandle { + ph, info + } + } + + /// Registers a hexchat plugin. pub fn register(&mut self, name: &str, desc: &str, ver: &str) { unsafe { - let ph = &mut *self.ph; - if let Some(hexchat_plugingui_add) = ph.hexchat_plugingui_add { - let filename = self.filename.take().expect("Attempt to re-register a plugin"); - let name = CString::new(name).unwrap(); - let desc = CString::new(desc).unwrap(); - let ver = CString::new(ver).unwrap(); - self.fakehandle = hexchat_plugingui_add(self.ph, filename.as_ptr(), name.as_ptr(), desc.as_ptr(), ver.as_ptr(), ::std::ptr::null_mut()); + let info = self.info; + if !(*info.name).is_null() || !(*info.desc).is_null() || !(*info.vers).is_null() { + panic!("Attempt to re-register a plugin"); + } + let name = CString::new(name).unwrap(); + let desc = CString::new(desc).unwrap(); + let ver = CString::new(ver).unwrap(); + // these shouldn't panic. if they do, we'll need to free them afterwards. + (*info.name) = name.into_raw(); + (*info.desc) = desc.into_raw(); + (*info.vers) = ver.into_raw(); + } + } + + /// Ensures the current context is valid. + /// + /// # Panics + /// + /// This function may panic if it's called while hexchat is closing. + // NOTE: using a closure is nicer. + // TODO check if this is actually safe + pub fn ensure_valid_context<F, R>(&mut self, f: F) -> R where F: FnOnce(EnsureValidContext) -> R { + // let ctx = self.get_context(); + // if !self.set_context(ctx) { + // // invalid context + // // TODO fix up the context + // unimplemented!() + // } + // f(EnsureValidContext { ph: self }) + let ctx = self.get_context(); + // need this here because we don't have NLL yet + let res = self.with_context(&ctx, f); + match res { + Result::Ok(r @ _) => r, + Result::Err(e @ _) => { + let nctx = self.find_valid_context().expect("ensure_valid_context failed (find_valid_context failed), was hexchat closing?"); + self.with_context(&nctx, e.get_closure()).ok().expect("ensure_valid_context failed, was hexchat closing?") + } + } + } + + /// Returns the current context. + /// + /// Note: The returned context may be invalid. Use [`set_context`] to check. + /// + /// [`set_context`]: #method.set_context + pub fn get_context(&mut self) -> Context { + unsafe { + Context { ctx: ((*self.ph).hexchat_get_context)(self.ph) } + } + } + + /// Sets the current context. + /// + /// Returns `true` if the context is valid, `false` otherwise. + pub fn set_context(&mut self, ctx: &Context) -> bool { + unsafe { + ((*self.ph).hexchat_set_context)(self.ph, ctx.ctx) != 0 + } + } + + /// Do something in a valid context. + /// + /// Note that this changes the active context and doesn't change it back. + /// + /// # Errors + /// + /// Returns `Err(InvalidContextError(f))` if the context is invalid. See [`set_context`]. Otherwise, + /// calls `f` and returns `Ok(its result)`. + /// + /// Note that `InvalidContextError` contains the original closure. This allows you to retry. + /// + /// [`set_context`]: #method.set_context + // this is probably safe to inline, and actually a good idea for ensure_valid_context + #[inline] + pub fn with_context<F, R>(&mut self, ctx: &Context, f: F) -> Result<R, InvalidContextError<F, R>> where F: FnOnce(EnsureValidContext) -> R { + if !self.set_context(ctx) { + Err(InvalidContextError(f)) + } else { + Ok(f(EnsureValidContext { ph: self })) + } + } + + /// Sets a command hook + pub fn hook_command<F>(&mut self, cmd: &str, cb: F, pri: i32, help: Option<&str>) -> CommandHookHandle where F: Fn(&mut PluginHandle, Word, WordEol) -> Eat + 'static + ::std::panic::RefUnwindSafe { + unsafe extern "C" fn callback(word: *const *const libc::c_char, word_eol: *const *const libc::c_char, ud: *mut libc::c_void) -> libc::c_int { + let f: *const CommandHookUd = ud as *const CommandHookUd; + match catch_unwind(|| { + let word = Word::new(word); + let word_eol = WordEol::new(word_eol); + ((*f).0)(&mut PluginHandle::new((*f).1, (*f).2), word, word_eol).do_eat as libc::c_int + }) { + Result::Ok(v @ _) => v, + Result::Err(e @ _) => { + let ph = (*f).1; + // if it's a &str or String, just print it + if let Some(estr) = e.downcast_ref::<&str>() { + hexchat_print_str(ph, estr, false); + } else if let Some(estring) = e.downcast_ref::<String>() { + hexchat_print_str(ph, &estring, false); + } + 0 // EAT_NONE + } + } + } + let b: Box<CommandHookUd> = Box::new((Box::new(cb), self.ph, self.info)); + let name = CString::new(cmd).unwrap(); + let help_text = help.map(CString::new).map(Result::unwrap); + let bp = Box::into_raw(b); + unsafe { + let res = ((*self.ph).hexchat_hook_command)(self.ph, name.as_ptr(), pri as libc::c_int, callback, help_text.as_ref().map(|s| s.as_ptr()).unwrap_or(ptr::null()), bp as *mut _); + assert!(!res.is_null()); + CommandHookHandle { ph: self.ph, hh: res, _f: PhantomData } + } + } + + /// Prints to the hexchat buffer. + // this checks the context internally. if it didn't, it wouldn't be safe to have here. + pub fn print(&mut self, s: &str) { + unsafe { + hexchat_print_str(self.ph, s, true); + } + } + + // ******* // + // PRIVATE // + // ******* // + + fn find_valid_context(&mut self) -> Option<Context> { + unsafe { + let ph = self.ph; + // TODO wrap this in a safer API, with proper Drop + #[allow(unused_mut)] + let mut list = ((*ph).hexchat_list_get)(ph, cstr(b"channels\0")); + // hexchat does this thing where it puts a context in a list_str. + // this is the proper way to do this + if ((*ph).hexchat_list_next)(ph, list) != 0 { + // if this panics we may leak some memory. it's not a big deal tho, as it indicates + // a bug in hexchat-plugin.rs. + let ctx = ((*ph).hexchat_list_str)(ph, list, cstr(b"context\0")) as *const internals::HexchatContext; + ((*ph).hexchat_list_free)(ph, list); + Some(Context { ctx }) + } else { + ((*ph).hexchat_list_free)(ph, list); + None } - self.registered = true; } } } +impl<'a> EnsureValidContext<'a> { +/* + * These cause UB: + * `hexchat_command` may invalidate the plugin context. + * `hexchat_find_context` and `hexchat_nickcmp` use the plugin context without checking it. + * `hexchat_get_prefs` uses the plugin context if name == "state_cursor" or "id" (or anything with + * the same hash). + * `hexchat_list_get` uses the plugin context if name == "notify" (or anything with the same hash). + * `hexchat_list_str`, `hexchat_list_int`, + * `hexchat_emit_print`, `hexchat_emit_print_attrs` use the plugin context. + * `hexchat_send_modes` uses the plugin context. + * We need to wrap them (or, alternatively, hexchat_command). However, there's no (safe) way to get + * a valid context afterwards. + * - Actually that's a lie. Hexchat does a trick to give you a context as part of the channel list. + * We can use that to our advantage. I'm not sure if it's better to wrap hexchat_command or the + * other functions, tho. + * (Do we want to walk a linked list every time we use hexchat_command? I'd think + * hexchat_command is the most used API function... Plus, emit_print could indirectly + * invalidate the context as well.) + * + * For performance we put them behind an EnsureValidContext - things that don't invalidate the + * context take an `&mut self`, things that do take an `self`. + */ + + pub fn find_context(&mut self, servname: Option<&str>, channel: Option<&str>) -> Option<Context> { + // TODO + unimplemented!() + } + + pub fn nickcmp(&mut self, nick1: &str, nick2: &str) -> ::std::cmp::Ordering { + // TODO + unimplemented!() + } + + pub fn send_modes(&mut self) { + // TODO + unimplemented!() + } + + pub fn emit_print(self) { + // TODO + unimplemented!() + } + + pub fn emit_print_attrs(self) { + // TODO + unimplemented!() + } + + // ******** // + // FORWARDS // + // ******** // + + pub fn get_context(&mut self) -> Context { + self.ph.get_context() + } + + /// Sets the current context. + /// + /// Returns `true` if the context is valid, `false` otherwise. + pub fn set_context(&mut self, ctx: &Context) -> bool { + self.ph.set_context(ctx) + } + + /// Prints to the hexchat buffer. + // TODO check if this triggers event hooks (which could call /close and invalidate the + // context). + pub fn print(&mut self, s: &str) { + self.ph.print(s) + } +} + +// ******* // +// PRIVATE // +// ******* // + +// Type aliases, used for safety type checking. +/// Userdata type used by a command hook. +// We actually do want RefUnwindSafe. This function may be called multiple times, and it's not +// automatically invalidated if it panics, so it may be called again after it panics. If you need +// mutable state, std provides std::sync::Mutex which has poisoning. Other interior mutability with +// poisoning could also be used. std doesn't have anything for single-threaded performance (yet), +// but hexchat isn't particularly performance-critical. +type CommandHookUd = (Box<Fn(&mut PluginHandle, Word, WordEol) -> Eat + ::std::panic::RefUnwindSafe>, *mut internals::Ph, PluginInfo); + +/// The contents of an empty CStr. +/// +/// This is useful where you need a non-null CStr. +// NOTE: MUST BE b"\0"! +const EMPTY_CSTRING_DATA: &[u8] = b"\0"; + +/// Converts a nul-terminated const bstring to a C string. +/// +/// # Panics +/// +/// Panics if b contains embedded nuls. +// TODO const fn, once that's possible +fn cstr(b: &'static [u8]) -> *const libc::c_char { + CStr::from_bytes_with_nul(b).unwrap().as_ptr() +} + +/// Prints an &str to hexchat, trying to avoid allocations. +/// +/// # Safety +/// +/// This function does not check the passed in argument. +/// +/// # Panics +/// +/// Panics if panic_on_nul is true and the string contains embedded nuls. +unsafe fn hexchat_print_str(ph: *mut internals::Ph, s: &str, panic_on_nul: bool) { + match CString::new(s) { + Result::Ok(cs @ _) => { + let csr: &CStr = &cs; + ((*ph).hexchat_print)(ph, csr.as_ptr()) + }, + e @ _ => if panic_on_nul {e.unwrap();}, // TODO nul_position? + } +} + +/// Holds name, desc, vers +// This is kinda naughty - we modify these values after returning from hexchat_plugin_init, during +// the deinitialization. +// However, if my reading of the HexChat code is correct, this is "ok". +#[derive(Copy, Clone)] +struct PluginInfo { + name: *mut *const libc::c_char, + desc: *mut *const libc::c_char, + vers: *mut *const libc::c_char, +} + +impl PluginInfo { + /// Creates a PluginInfo. + /// + /// # Panics + /// + /// This function explicitly doesn't panic. Call unwrap() on the result instead. + fn new(name: *mut *const libc::c_char, desc: *mut *const libc::c_char, vers: *mut *const libc::c_char) -> Option<PluginInfo> { + if name.is_null() || desc.is_null() || vers.is_null() || name == desc || desc == vers || name == vers { + None + } else { + Some(unsafe { PluginInfo::new_unchecked(name, desc, vers) }) + } + } + + /// Creates a PluginInfo without checking the arguments. + /// + /// # Safety + /// + /// This function is unsafe, as it doesn't check the validity of the arguments. You're expected + /// to only pass in non-aliased non-null pointers. Use new if unsure. + unsafe fn new_unchecked(name: *mut *const libc::c_char, desc: *mut *const libc::c_char, vers: *mut *const libc::c_char) -> PluginInfo { + PluginInfo { + name, desc, vers + } + } + + /// Drop relevant CStrings. + /// + /// # Safety + /// + /// This function is unsafe because calling it may trigger Undefined Behaviour. See also + /// [CString::from_raw]. + /// + /// [from_raw]: https://doc.rust-lang.org/std/ffi/struct.CString.html#method.from_raw + unsafe fn drop_info(&mut self) { + if !(*self.name).is_null() { + mem::drop(CString::from_raw(*self.name as *mut _)); + *self.name = cstr(EMPTY_CSTRING_DATA); + } + if !(*self.desc).is_null() { + mem::drop(CString::from_raw(*self.desc as *mut _)); + *self.desc = cstr(EMPTY_CSTRING_DATA); + } + if !(*self.vers).is_null() { + mem::drop(CString::from_raw(*self.vers as *mut _)); + *self.vers = cstr(EMPTY_CSTRING_DATA); + } + } +} + +/// Plugin data stored in the hexchat plugin_handle. +struct PhUserdata { + plug: Box<Plugin>, + pluginfo: PluginInfo, +} + +/// Puts the userdata in the plugin handle. +/// +/// # Safety +/// +/// This function is unsafe because it doesn't check if the pointer is valid. +/// +/// Improper use of this function can leak memory. +unsafe fn put_userdata(ph: *mut internals::Ph, ud: Box<PhUserdata>) { + (*ph).userdata = Box::into_raw(ud) as *mut libc::c_void; +} + +// unsafe fn get_userdata(ph: *mut internals::Ph) -> *const PhUserdata { +// (*ph).userdata as *const _ +// } + +/// Pops the userdata from the plugin handle. +/// +/// # Safety +/// +/// This function is unsafe because it doesn't check if the pointer is valid. +unsafe fn pop_userdata(ph: *mut internals::Ph) -> Box<PhUserdata> { + Box::from_raw(mem::replace(&mut (*ph).userdata, ptr::null_mut()) as *mut PhUserdata) +} + +// *********************** // +// PUBLIC OUT OF NECESSITY // +// *********************** // + #[doc(hidden)] pub unsafe fn hexchat_plugin_init<T>(plugin_handle: *mut libc::c_void, plugin_name: *mut *const libc::c_char, plugin_desc: *mut *const libc::c_char, plugin_version: *mut *const libc::c_char, arg: *const libc::c_char) -> libc::c_int - where T: Plugin + Default { - if plugin_handle.is_null() { + where T: Plugin + Default + 'static { + if plugin_handle.is_null() || plugin_name.is_null() || plugin_desc.is_null() || plugin_version.is_null() { // we can't really do anything here. - eprintln!("hexchat_plugin_init called with a null plugin_handle. This is an error!"); + eprintln!("hexchat_plugin_init called with a null pointer that shouldn't be null - broken hexchat"); // TODO maybe call abort. return 0; } - let ph = &mut *(plugin_handle as *mut internals::Ph); + let ph = plugin_handle as *mut internals::Ph; // clear the "userdata" field first thing - if the deinit function gets called (wrong hexchat // version, other issues), we don't wanna try to drop the hexchat_dummy or hexchat_read_fd // function as if it were a Box! - ph.userdata = ::std::ptr::null_mut(); - // we set these to empty strings because rust strings aren't nul-terminated. which means we - // need to *allocate* nul-terminated strings for the real values, and hexchat has no way of - // freeing these. - // BUT before we set them, read the filename off plugin_name - we'll need it! - // (TODO figure out how to make this NOT break the plugins list) - let filename = CStr::from_ptr(*plugin_name).to_owned(); - let empty_cstr = CStr::from_bytes_with_nul_unchecked(EMPTY_CSTRING_DATA).as_ptr(); - *plugin_name = empty_cstr; - *plugin_desc = empty_cstr; - *plugin_version = empty_cstr; + (*ph).userdata = ptr::null_mut(); + // read the filename so we can pass it on later. + let filename = if !(*plugin_name).is_null() { + if let Ok(fname) = CStr::from_ptr(*plugin_name).to_owned().into_string() { + fname + } else { + eprintln!("failed to convert filename to utf8 - broken hexchat"); + return 0; + } + } else { + // no filename specified for some reason, but we can still load + String::new() // empty string + }; + // these may be null, unless initialization is successful. + // we set them to null as markers. + *plugin_name = ptr::null(); + *plugin_desc = ptr::null(); + *plugin_version = ptr::null(); // do some version checks for safety - if let Some(hexchat_get_info) = ph.hexchat_get_info { - let ver: *const libc::c_char = hexchat_get_info(ph, CStr::from_bytes_with_nul_unchecked(b"version\0").as_ptr()); + // NOTE: calling hexchat functions with null plugin_name, plugin_desc, plugin_version is a bit + // dangerous. this particular case is "ok". + { + let ver = ((*ph).hexchat_get_info)(ph, cstr(b"version\0")); // this shouldn't panic let cstr = CStr::from_ptr(ver); if let Ok(ver) = cstr.to_str() { let mut iter = ver.split('.'); - let a = iter.next().map(i32::from_str).and_then(Result::ok); - let b = iter.next().map(i32::from_str).and_then(Result::ok); - let c = iter.next().map(i32::from_str).and_then(Result::ok); - if !match a.unwrap_or(0) { - 0 | 1 => false, - 2 => match b.unwrap_or(0) { - // range patterns are a bit broken - 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 => false, - 9 => match c.unwrap_or(0) { - 0 | 1 | 2 | 3 | 4 | 5 => false, - 6 => - // min acceptable version = 2.9.6 - true, - _ => true, - }, - _ => true, - }, - _ => true, - } { - // TODO print: "error loading plugin: hexchat too old"? + let a = iter.next().map(i32::from_str).and_then(Result::ok).unwrap_or(0); + let b = iter.next().map(i32::from_str).and_then(Result::ok).unwrap_or(0); + let c = iter.next().map(i32::from_str).and_then(Result::ok).unwrap_or(0); + // 2.9.6 or greater + if !(a > 2 || (a == 2 && (b > 9 || (b == 9 && (c > 6 || (c == 6)))))) { return 0; } } else { return 0; } } - let r: thread::Result<Option<Box<_>>> = catch_unwind(|| { - let mut plug = T::default(); - let mut pluginhandle = PluginHandle { - ph: plugin_handle as *mut _, - registered: false, - filename: Some(filename), - fakehandle: ::std::ptr::null(), - }; - if plug.init(&mut pluginhandle) { - if pluginhandle.registered { - Some(Box::new((plug, pluginhandle.fakehandle))) + let mut pluginfo = if let Some(pluginfo) = PluginInfo::new(plugin_name, plugin_desc, plugin_version) { + pluginfo + } else { + return 0; + }; + let r: thread::Result<Option<Box<_>>> = { + catch_unwind(move || { + let mut pluginhandle = PluginHandle { + ph: ph, + info: pluginfo, + }; + let plug = T::default(); + if plug.init(&mut pluginhandle, if !arg.is_null() { Some(CStr::from_ptr(arg).to_str().expect("arg not valid utf-8 - broken hexchat")) } else { None }) { + if !(pluginfo.name.is_null() || pluginfo.desc.is_null() || pluginfo.vers.is_null()) { + Some(Box::new(PhUserdata { plug: Box::new(plug), pluginfo })) + } else { + // TODO log: forgot to call register + None + } } else { - // TODO log: forgot to call register None } - } else { - None - } - }); - if r.is_ok() { - if let Ok(Some(plug)) = r { - ph.userdata = Box::into_raw(plug) as *mut libc::c_void; - 1 - } else { + }) + }; + match r { + Result::Ok(Option::Some(plug @ _)) => { + if (*plugin_name).is_null() || (*plugin_desc).is_null() || (*plugin_version).is_null() { + // TODO deallocate any which are non-null + pluginfo.drop_info(); + 0 + } else { + put_userdata(ph, plug); + 1 + } + }, + r @ _ => { + // if the initialization fails, deinit doesn't get called, so we need to clean up + // ourselves. + + if let Err(_) = r { + // TODO try to log panic? + } 0 - } - } else { - // TODO try to log panic? - 0 + }, } } #[doc(hidden)] pub unsafe fn hexchat_plugin_deinit<T>(plugin_handle: *mut libc::c_void) where T: Plugin { - // plugin_handle should never be null, but just in case... + // plugin_handle should never be null, but just in case. if !plugin_handle.is_null() { - let ph = &mut *(plugin_handle as *mut internals::Ph); - if !ph.userdata.is_null() { - // - let userdata = ph.userdata; - ph.userdata = ::std::ptr::null_mut(); - // we use an explicit drop (instead of an implicit one) so this is less confusing/weird - // to read. - catch_unwind(|| { - let ph = &mut *(plugin_handle as *mut internals::Ph); - let (plug, fakehandle) = *Box::from_raw(userdata as *mut (T, *const internals::PluginGuiHandle)); - if let Some(hexchat_plugingui_remove) = ph.hexchat_plugingui_remove { - hexchat_plugingui_remove(ph, fakehandle); + let ph = plugin_handle as *mut internals::Ph; + // userdata should also never be null. + if !(*ph).userdata.is_null() { + { + let mut info: Option<PluginInfo> = None; + { + let mut ausinfo = ::std::panic::AssertUnwindSafe(&mut info); + catch_unwind(move || { + let userdata = *pop_userdata(ph); + **ausinfo = Some(userdata.pluginfo); + userdata.plug.deinit(&mut PluginHandle { ph, info: userdata.pluginfo }); + }).ok(); + } + if let Some(mut info) = info { + info.drop_info(); + } else { + eprintln!("I have no idea tbh, I didn't know `pop_userdata` could panic!"); } - ::std::mem::drop(plug); // suppress compiler warnings - }).ok(); + } + } else { + eprintln!("null userdata in hexchat_plugin_deinit - broken hexchat or broken hexchat-plugin.rs"); } } else { - eprintln!("hexchat_plugin_deinit called with a null plugin_handle. This is an error!"); + eprintln!("hexchat_plugin_deinit called with a null plugin_handle - broken hexchat"); } } |