diff options
author | Roy Marples <roy@marples.name> | 2008-01-05 19:25:55 +0000 |
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committer | Roy Marples <roy@marples.name> | 2008-01-05 19:25:55 +0000 |
commit | ac21d75300dabe83578e4373fcfd09d67c3a083b (patch) | |
tree | d5f8e2a16920add2277c79ff8a1b7e99ec2976df /src/rc/rc-plugin.c | |
parent | 112fbde453d55c49b7999d2e35496a8758aaa7b5 (diff) |
Add some .mk stubs to impersonate bsk .mk files to make writing our Makefiles easier. libeinfo, librc and rc now have their own seperate directories. More work is needed to tidy this up though.
Diffstat (limited to 'src/rc/rc-plugin.c')
-rw-r--r-- | src/rc/rc-plugin.c | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/src/rc/rc-plugin.c b/src/rc/rc-plugin.c new file mode 100644 index 00000000..613f049e --- /dev/null +++ b/src/rc/rc-plugin.c @@ -0,0 +1,241 @@ +/* + librc-plugin.c + Simple plugin handler + */ + +/* + * Copyright 2007 Roy Marples + * All rights reserved + + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/types.h> +#include <sys/wait.h> +#include <dirent.h> +#include <dlfcn.h> +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include "einfo.h" +#include "rc.h" +#include "rc-misc.h" +#include "rc-plugin.h" +#include "strlist.h" + +#define RC_PLUGIN_HOOK "rc_plugin_hook" + +bool rc_in_plugin = false; + +typedef struct plugin +{ + char *name; + void *handle; + int (*hook) (rc_hook_t, const char *); + struct plugin *next; +} plugin_t; + +static plugin_t *plugins = NULL; + +#ifndef __FreeBSD__ +dlfunc_t dlfunc (void * __restrict handle, const char * __restrict symbol) +{ + union { + void *d; + dlfunc_t f; + } rv; + + rv.d = dlsym (handle, symbol); + return (rv.f); +} +#endif + +void rc_plugin_load (void) +{ + DIR *dp; + struct dirent *d; + plugin_t *plugin = plugins; + char *p; + void *h; + int (*fptr) (rc_hook_t, const char *); + + /* Don't load plugins if we're in one */ + if (rc_in_plugin) + return; + + /* Ensure some sanity here */ + rc_plugin_unload (); + + if (! (dp = opendir (RC_PLUGINDIR))) + return; + + while ((d = readdir (dp))) { + if (d->d_name[0] == '.') + continue; + + p = rc_strcatpaths (RC_PLUGINDIR, d->d_name, NULL); + h = dlopen (p, RTLD_LAZY); + free (p); + if (! h) { + eerror ("dlopen: %s", dlerror ()); + continue; + } + + fptr = (int (*)(rc_hook_t, const char*)) dlfunc (h, RC_PLUGIN_HOOK); + if (! fptr) { + eerror ("%s: cannot find symbol `%s'", d->d_name, RC_PLUGIN_HOOK); + dlclose (h); + } else { + if (plugin) { + plugin->next = xmalloc (sizeof (plugin_t)); + plugin = plugin->next; + } else + plugin = plugins = xmalloc (sizeof (plugin_t)); + + memset (plugin, 0, sizeof (plugin_t)); + plugin->name = xstrdup (d->d_name); + plugin->handle = h; + plugin->hook = fptr; + } + } + closedir (dp); +} + +int rc_waitpid (pid_t pid) +{ + int status = 0; + pid_t savedpid = pid; + int retval = -1; + + errno = 0; + while ((pid = waitpid (savedpid, &status, 0)) > 0) { + if (pid == savedpid) + retval = WIFEXITED (status) ? WEXITSTATUS (status) : EXIT_FAILURE; + } + + return (retval); +} + +void rc_plugin_run (rc_hook_t hook, const char *value) +{ + plugin_t *plugin = plugins; + + /* Don't run plugins if we're in one */ + if (rc_in_plugin) + return; + + while (plugin) { + if (plugin->hook) { + int i; + int flags; + int pfd[2]; + pid_t pid; + + /* We create a pipe so that plugins can affect our environment + * vars, which in turn influence our scripts. */ + if (pipe (pfd) == -1) { + eerror ("pipe: %s", strerror (errno)); + return; + } + + /* Stop any scripts from inheriting us. + * This is actually quite important as without this, the splash + * plugin will probably hang when running in silent mode. */ + for (i = 0; i < 2; i++) + if ((flags = fcntl (pfd[i], F_GETFD, 0)) < 0 || + fcntl (pfd[i], F_SETFD, flags | FD_CLOEXEC) < 0) + eerror ("fcntl: %s", strerror (errno)); + + /* We run the plugin in a new process so we never crash + * or otherwise affected by it */ + if ((pid = fork ()) == -1) { + eerror ("fork: %s", strerror (errno)); + return; + } + + if (pid == 0) { + int retval; + + rc_in_plugin = true; + close (pfd[0]); + rc_environ_fd = fdopen (pfd[1], "w"); + retval = plugin->hook (hook, value); + fclose (rc_environ_fd); + rc_environ_fd = NULL; + + /* Just in case the plugin sets this to false */ + rc_in_plugin = true; + exit (retval); + } else { + char *buffer; + char *token; + char *p; + ssize_t nr; + + close (pfd[1]); + buffer = xmalloc (sizeof (char) * RC_LINEBUFFER); + memset (buffer, 0, RC_LINEBUFFER); + + while ((nr = read (pfd[0], buffer, RC_LINEBUFFER)) > 0) { + p = buffer; + while (*p && p - buffer < nr) { + token = strsep (&p, "="); + if (token) { + unsetenv (token); + if (*p) { + setenv (token, p, 1); + p += strlen (p) + 1; + } else + p++; + } + } + } + + free (buffer); + close (pfd[0]); + + rc_waitpid (pid); + } + } + plugin = plugin->next; + } +} + +void rc_plugin_unload (void) +{ + plugin_t *plugin = plugins; + plugin_t *next; + + while (plugin) { + next = plugin->next; + dlclose (plugin->handle); + free (plugin->name); + free (plugin); + plugin = next; + } + plugins = NULL; +} |