diff options
Diffstat (limited to 'filter.c')
| -rw-r--r-- | filter.c | 457 |
1 files changed, 457 insertions, 0 deletions
diff --git a/filter.c b/filter.c new file mode 100644 index 0000000000..70f5b74998 --- /dev/null +++ b/filter.c @@ -0,0 +1,457 @@ +/* filter.c: filter framework functions + * + * Copyright (C) 2006-2014 cgit Development Team <cgit@lists.zx2c4.com> + * + * Licensed under GNU General Public License v2 + * (see COPYING for full license text) + */ + +#include "cgit.h" +#include "html.h" +#ifndef NO_LUA +#include <dlfcn.h> +#include <lua.h> +#include <lualib.h> +#include <lauxlib.h> +#endif + +static inline void reap_filter(struct cgit_filter *filter) +{ + if (filter && filter->cleanup) + filter->cleanup(filter); +} + +void cgit_cleanup_filters(void) +{ + int i; + reap_filter(ctx.cfg.about_filter); + reap_filter(ctx.cfg.commit_filter); + reap_filter(ctx.cfg.source_filter); + reap_filter(ctx.cfg.email_filter); + reap_filter(ctx.cfg.owner_filter); + reap_filter(ctx.cfg.auth_filter); + for (i = 0; i < cgit_repolist.count; ++i) { + reap_filter(cgit_repolist.repos[i].about_filter); + reap_filter(cgit_repolist.repos[i].commit_filter); + reap_filter(cgit_repolist.repos[i].source_filter); + reap_filter(cgit_repolist.repos[i].email_filter); + reap_filter(cgit_repolist.repos[i].owner_filter); + } +} + +static int open_exec_filter(struct cgit_filter *base, va_list ap) +{ + struct cgit_exec_filter *filter = (struct cgit_exec_filter *)base; + int pipe_fh[2]; + int i; + + for (i = 0; i < filter->base.argument_count; i++) + filter->argv[i + 1] = va_arg(ap, char *); + + filter->old_stdout = chk_positive(dup(STDOUT_FILENO), + "Unable to duplicate STDOUT"); + chk_zero(pipe(pipe_fh), "Unable to create pipe to subprocess"); + filter->pid = chk_non_negative(fork(), "Unable to create subprocess"); + if (filter->pid == 0) { + close(pipe_fh[1]); + chk_non_negative(dup2(pipe_fh[0], STDIN_FILENO), + "Unable to use pipe as STDIN"); + execvp(filter->cmd, filter->argv); + die_errno("Unable to exec subprocess %s", filter->cmd); + } + close(pipe_fh[0]); + chk_non_negative(dup2(pipe_fh[1], STDOUT_FILENO), + "Unable to use pipe as STDOUT"); + close(pipe_fh[1]); + return 0; +} + +static int close_exec_filter(struct cgit_filter *base) +{ + struct cgit_exec_filter *filter = (struct cgit_exec_filter *)base; + int i, exit_status = 0; + + chk_non_negative(dup2(filter->old_stdout, STDOUT_FILENO), + "Unable to restore STDOUT"); + close(filter->old_stdout); + if (filter->pid < 0) + goto done; + waitpid(filter->pid, &exit_status, 0); + if (WIFEXITED(exit_status)) + goto done; + die("Subprocess %s exited abnormally", filter->cmd); + +done: + for (i = 0; i < filter->base.argument_count; i++) + filter->argv[i + 1] = NULL; + return WEXITSTATUS(exit_status); + +} + +static void fprintf_exec_filter(struct cgit_filter *base, FILE *f, const char *prefix) +{ + struct cgit_exec_filter *filter = (struct cgit_exec_filter *)base; + fprintf(f, "%sexec:%s\n", prefix, filter->cmd); +} + +static void cleanup_exec_filter(struct cgit_filter *base) +{ + struct cgit_exec_filter *filter = (struct cgit_exec_filter *)base; + if (filter->argv) { + free(filter->argv); + filter->argv = NULL; + } + if (filter->cmd) { + free(filter->cmd); + filter->cmd = NULL; + } +} + +static struct cgit_filter *new_exec_filter(const char *cmd, int argument_count) +{ + struct cgit_exec_filter *f; + int args_size = 0; + + f = xmalloc(sizeof(*f)); + /* We leave argv for now and assign it below. */ + cgit_exec_filter_init(f, xstrdup(cmd), NULL); + f->base.argument_count = argument_count; + args_size = (2 + argument_count) * sizeof(char *); + f->argv = xmalloc(args_size); + memset(f->argv, 0, args_size); + f->argv[0] = f->cmd; + return &f->base; +} + +void cgit_exec_filter_init(struct cgit_exec_filter *filter, char *cmd, char **argv) +{ + memset(filter, 0, sizeof(*filter)); + filter->base.open = open_exec_filter; + filter->base.close = close_exec_filter; + filter->base.fprintf = fprintf_exec_filter; + filter->base.cleanup = cleanup_exec_filter; + filter->cmd = cmd; + filter->argv = argv; + /* The argument count for open_filter is zero by default, unless called from new_filter, above. */ + filter->base.argument_count = 0; +} + +#ifdef NO_LUA +void cgit_init_filters(void) +{ +} +#endif + +#ifndef NO_LUA +static ssize_t (*libc_write)(int fd, const void *buf, size_t count); +static ssize_t (*filter_write)(struct cgit_filter *base, const void *buf, size_t count) = NULL; +static struct cgit_filter *current_write_filter = NULL; + +void cgit_init_filters(void) +{ + libc_write = dlsym(RTLD_NEXT, "write"); + if (!libc_write) + die("Could not locate libc's write function"); +} + +ssize_t write(int fd, const void *buf, size_t count) +{ + if (fd != STDOUT_FILENO || !filter_write) + return libc_write(fd, buf, count); + return filter_write(current_write_filter, buf, count); +} + +static inline void hook_write(struct cgit_filter *filter, ssize_t (*new_write)(struct cgit_filter *base, const void *buf, size_t count)) +{ + /* We want to avoid buggy nested patterns. */ + assert(filter_write == NULL); + assert(current_write_filter == NULL); + current_write_filter = filter; + filter_write = new_write; +} + +static inline void unhook_write(void) +{ + assert(filter_write != NULL); + assert(current_write_filter != NULL); + filter_write = NULL; + current_write_filter = NULL; +} + +struct lua_filter { + struct cgit_filter base; + char *script_file; + lua_State *lua_state; +}; + +static void error_lua_filter(struct lua_filter *filter) +{ + die("Lua error in %s: %s", filter->script_file, lua_tostring(filter->lua_state, -1)); + lua_pop(filter->lua_state, 1); +} + +static ssize_t write_lua_filter(struct cgit_filter *base, const void *buf, size_t count) +{ + struct lua_filter *filter = (struct lua_filter *)base; + + lua_getglobal(filter->lua_state, "filter_write"); + lua_pushlstring(filter->lua_state, buf, count); + if (lua_pcall(filter->lua_state, 1, 0, 0)) { + error_lua_filter(filter); + errno = EIO; + return -1; + } + return count; +} + +static inline int hook_lua_filter(lua_State *lua_state, void (*fn)(const char *txt)) +{ + const char *str; + ssize_t (*save_filter_write)(struct cgit_filter *base, const void *buf, size_t count); + struct cgit_filter *save_filter; + + str = lua_tostring(lua_state, 1); + if (!str) + return 0; + + save_filter_write = filter_write; + save_filter = current_write_filter; + unhook_write(); + fn(str); + hook_write(save_filter, save_filter_write); + + return 0; +} + +static int html_lua_filter(lua_State *lua_state) +{ + return hook_lua_filter(lua_state, html); +} + +static int html_txt_lua_filter(lua_State *lua_state) +{ + return hook_lua_filter(lua_state, html_txt); +} + +static int html_attr_lua_filter(lua_State *lua_state) +{ + return hook_lua_filter(lua_state, html_attr); +} + +static int html_url_path_lua_filter(lua_State *lua_state) +{ + return hook_lua_filter(lua_state, html_url_path); +} + +static int html_url_arg_lua_filter(lua_State *lua_state) +{ + return hook_lua_filter(lua_state, html_url_arg); +} + +static int html_include_lua_filter(lua_State *lua_state) +{ + return hook_lua_filter(lua_state, (void (*)(const char *))html_include); +} + +static void cleanup_lua_filter(struct cgit_filter *base) +{ + struct lua_filter *filter = (struct lua_filter *)base; + + if (!filter->lua_state) + return; + + lua_close(filter->lua_state); + filter->lua_state = NULL; + if (filter->script_file) { + free(filter->script_file); + filter->script_file = NULL; + } +} + +static int init_lua_filter(struct lua_filter *filter) +{ + if (filter->lua_state) + return 0; + + if (!(filter->lua_state = luaL_newstate())) + return 1; + + luaL_openlibs(filter->lua_state); + + lua_pushcfunction(filter->lua_state, html_lua_filter); + lua_setglobal(filter->lua_state, "html"); + lua_pushcfunction(filter->lua_state, html_txt_lua_filter); + lua_setglobal(filter->lua_state, "html_txt"); + lua_pushcfunction(filter->lua_state, html_attr_lua_filter); + lua_setglobal(filter->lua_state, "html_attr"); + lua_pushcfunction(filter->lua_state, html_url_path_lua_filter); + lua_setglobal(filter->lua_state, "html_url_path"); + lua_pushcfunction(filter->lua_state, html_url_arg_lua_filter); + lua_setglobal(filter->lua_state, "html_url_arg"); + lua_pushcfunction(filter->lua_state, html_include_lua_filter); + lua_setglobal(filter->lua_state, "html_include"); + + if (luaL_dofile(filter->lua_state, filter->script_file)) { + error_lua_filter(filter); + lua_close(filter->lua_state); + filter->lua_state = NULL; + return 1; + } + return 0; +} + +static int open_lua_filter(struct cgit_filter *base, va_list ap) +{ + struct lua_filter *filter = (struct lua_filter *)base; + int i; + + if (init_lua_filter(filter)) + return 1; + + hook_write(base, write_lua_filter); + + lua_getglobal(filter->lua_state, "filter_open"); + for (i = 0; i < filter->base.argument_count; ++i) + lua_pushstring(filter->lua_state, va_arg(ap, char *)); + if (lua_pcall(filter->lua_state, filter->base.argument_count, 0, 0)) { + error_lua_filter(filter); + return 1; + } + return 0; +} + +static int close_lua_filter(struct cgit_filter *base) +{ + struct lua_filter *filter = (struct lua_filter *)base; + int ret = 0; + + lua_getglobal(filter->lua_state, "filter_close"); + if (lua_pcall(filter->lua_state, 0, 1, 0)) { + error_lua_filter(filter); + ret = -1; + } else { + ret = lua_tonumber(filter->lua_state, -1); + lua_pop(filter->lua_state, 1); + } + + unhook_write(); + return ret; +} + +static void fprintf_lua_filter(struct cgit_filter *base, FILE *f, const char *prefix) +{ + struct lua_filter *filter = (struct lua_filter *)base; + fprintf(f, "%slua:%s\n", prefix, filter->script_file); +} + + +static struct cgit_filter *new_lua_filter(const char *cmd, int argument_count) +{ + struct lua_filter *filter; + + filter = xmalloc(sizeof(*filter)); + memset(filter, 0, sizeof(*filter)); + filter->base.open = open_lua_filter; + filter->base.close = close_lua_filter; + filter->base.fprintf = fprintf_lua_filter; + filter->base.cleanup = cleanup_lua_filter; + filter->base.argument_count = argument_count; + filter->script_file = xstrdup(cmd); + + return &filter->base; +} + +#endif + + +int cgit_open_filter(struct cgit_filter *filter, ...) +{ + int result; + va_list ap; + if (!filter) + return 0; + va_start(ap, filter); + result = filter->open(filter, ap); + va_end(ap); + return result; +} + +int cgit_close_filter(struct cgit_filter *filter) +{ + if (!filter) + return 0; + return filter->close(filter); +} + +void cgit_fprintf_filter(struct cgit_filter *filter, FILE *f, const char *prefix) +{ + filter->fprintf(filter, f, prefix); +} + + + +static const struct { + const char *prefix; + struct cgit_filter *(*ctor)(const char *cmd, int argument_count); +} filter_specs[] = { + { "exec", new_exec_filter }, +#ifndef NO_LUA + { "lua", new_lua_filter }, +#endif +}; + +struct cgit_filter *cgit_new_filter(const char *cmd, filter_type filtertype) +{ + char *colon; + int i; + size_t len; + int argument_count; + + if (!cmd || !cmd[0]) + return NULL; + + colon = strchr(cmd, ':'); + len = colon - cmd; + /* + * In case we're running on Windows, don't allow a single letter before + * the colon. + */ + if (len == 1) + colon = NULL; + + switch (filtertype) { + case AUTH: + argument_count = 12; + break; + + case EMAIL: + argument_count = 2; + break; + + case OWNER: + argument_count = 0; + break; + + case SOURCE: + case ABOUT: + argument_count = 1; + break; + + case COMMIT: + default: + argument_count = 0; + break; + } + + /* If no prefix is given, exec filter is the default. */ + if (!colon) + return new_exec_filter(cmd, argument_count); + + for (i = 0; i < ARRAY_SIZE(filter_specs); i++) { + if (len == strlen(filter_specs[i].prefix) && + !strncmp(filter_specs[i].prefix, cmd, len)) + return filter_specs[i].ctor(colon + 1, argument_count); + } + + die("Invalid filter type: %.*s", (int) len, cmd); +} |