* add support for static service definitions for the daemon using XML fragments

git-svn-id: file:///home/lennart/svn/public/avahi/trunk@115 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe

1 files changed, 618 insertions, 0 deletions

diff --git a/avahi-daemon/static-services.c b/avahi-daemon/static-services.c
new file mode 100644
index 0000000..89e8122
--- /dev/null
+++ b/avahi-daemon/static-services.c
@@ -0,0 +1,618 @@
+/* $Id$ */
+
+/***
+  This file is part of avahi.
+ 
+  avahi is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as
+  published by the Free Software Foundation; either version 2.1 of the
+  License, or (at your option) any later version.
+ 
+  avahi 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 Lesser General
+  Public License for more details.
+ 
+  You should have received a copy of the GNU Lesser General Public
+  License along with avahi; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <sys/stat.h>
+#include <glob.h>
+#include <limits.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <glib.h>
+#include <expat.h>
+
+#include <avahi-core/llist.h>
+
+#include "main.h"
+
+typedef struct StaticService StaticService;
+typedef struct StaticServiceGroup StaticServiceGroup;
+
+struct StaticService {
+    StaticServiceGroup *group;
+    
+    gchar *type;
+    gchar *domain_name;
+    gchar *host_name;
+    guint16 port;
+
+    AvahiStringList *txt_records;
+    
+    AVAHI_LLIST_FIELDS(StaticService, services);
+};
+
+struct StaticServiceGroup {
+    gchar *filename;
+    time_t mtime;
+
+    gchar *name, *chosen_name;
+    gboolean replace_wildcards;
+
+    AvahiEntryGroup *entry_group;
+    AVAHI_LLIST_HEAD(StaticService, services);
+    AVAHI_LLIST_FIELDS(StaticServiceGroup, groups);
+};
+
+static AVAHI_LLIST_HEAD(StaticServiceGroup, groups) = NULL;
+
+static gchar *replacestr(const gchar *pattern, const gchar *a, const gchar *b) {
+    gchar *r = NULL, *e, *n;
+
+    while ((e = strstr(pattern, a))) {
+        gchar *k;
+
+        k = g_strndup(pattern, e - pattern);
+        if (r)
+            n = g_strconcat(r, k, b, NULL);
+        else
+            n = g_strconcat(k, b, NULL);
+
+        g_free(k);
+        g_free(r);
+        r = n;
+
+        pattern = e + strlen(a);
+    }
+
+    if (!r)
+        return g_strdup(pattern);
+
+    n = g_strconcat(r, pattern, NULL);
+    g_free(r);
+
+    return n;
+}
+
+static void add_static_service_group_to_server(StaticServiceGroup *g);
+static void remove_static_service_group_from_server(StaticServiceGroup *g);
+
+static StaticService *static_service_new(StaticServiceGroup *group) {
+    StaticService *s;
+    
+    g_assert(group);
+    s = g_new(StaticService, 1);
+    s->group = group;
+
+    s->type = s->host_name = s->domain_name = NULL;
+    s->port = 0;
+
+    s->txt_records = NULL;
+
+    AVAHI_LLIST_PREPEND(StaticService, services, group->services, s);
+
+    return s;
+}
+
+static StaticServiceGroup *static_service_group_new(gchar *filename) {
+    StaticServiceGroup *g;
+    g_assert(filename);
+
+    g = g_new(StaticServiceGroup, 1);
+    g->filename = g_strdup(filename);
+    g->mtime = 0;
+    g->name = g->chosen_name = NULL;
+    g->replace_wildcards = FALSE;
+    g->entry_group = NULL;
+
+    AVAHI_LLIST_HEAD_INIT(StaticService, g->services);
+    AVAHI_LLIST_PREPEND(StaticServiceGroup, groups, groups, g);
+
+    return g;
+}
+
+static void static_service_free(StaticService *s) {
+    g_assert(s);
+    
+    AVAHI_LLIST_REMOVE(StaticService, services, s->group->services, s);
+
+    g_free(s->type);
+    g_free(s->host_name);
+    g_free(s->domain_name);
+
+    avahi_string_list_free(s->txt_records);
+    
+    g_free(s);
+}
+
+static void static_service_group_free(StaticServiceGroup *g) {
+    g_assert(g);
+
+    remove_static_service_group_from_server(g);
+
+    while (g->services)
+        static_service_free(g->services);
+
+    AVAHI_LLIST_REMOVE(StaticServiceGroup, groups, groups, g);
+
+    g_free(g->filename);
+    g_free(g->name);
+    g_free(g->chosen_name);
+    g_free(g);
+}
+
+static void entry_group_callback(AvahiServer *s, AvahiEntryGroup *eg, AvahiEntryGroupState state, gpointer userdata) {
+    StaticServiceGroup *g = userdata;
+    
+    g_assert(s);
+    g_assert(g);
+    
+    if (state == AVAHI_ENTRY_GROUP_COLLISION) {
+        gchar *n;
+
+        remove_static_service_group_from_server(g);
+
+        n = avahi_alternative_service_name(g->chosen_name);
+        g_free(g->chosen_name);
+        g->chosen_name = n;
+
+        g_message("Service name conflict for \"%s\" (%s), retrying with \"%s\".", g->name, g->filename, g->chosen_name);
+
+        add_static_service_group_to_server(g);
+    } else
+        g_message("Service \"%s\" (%s) successfully establised.", g->chosen_name, g->filename);
+}
+
+static void add_static_service_group_to_server(StaticServiceGroup *g) {
+    StaticService *s;
+
+    g_assert(g);
+    
+    if (g->entry_group)
+        return;
+    
+    if (g->chosen_name)
+        g_free(g->chosen_name);
+    
+    if (g->replace_wildcards)
+        g->chosen_name = replacestr(g->name, "%h", avahi_server_get_host_name(avahi_server));
+    else
+        g->chosen_name = g_strdup(g->name);
+    
+    g->entry_group = avahi_entry_group_new(avahi_server, entry_group_callback, g);
+    
+    for (s = g->services; s; s = s->services_next) {
+
+        if (avahi_server_add_service_strlst(
+                avahi_server,
+                g->entry_group,
+                -1, AF_UNSPEC,
+                s->type, g->chosen_name,
+                s->domain_name, s->host_name, s->port,
+                s->txt_records) < 0) {
+            g_message("Failed to add service '%s' of type '%s', ignoring service group (%s)", g->chosen_name, s->type, g->filename);
+            remove_static_service_group_from_server(g);
+            return;
+        }
+    }
+
+    avahi_entry_group_commit(g->entry_group);
+}
+
+static void remove_static_service_group_from_server(StaticServiceGroup *g) {
+    g_assert(g);
+
+    if (g->entry_group) {
+        avahi_entry_group_free(g->entry_group);
+        g->entry_group = NULL;
+    }
+}
+
+typedef enum {
+    XML_TAG_INVALID,
+    XML_TAG_SERVICE_GROUP,
+    XML_TAG_NAME,
+    XML_TAG_SERVICE,
+    XML_TAG_TYPE,
+    XML_TAG_DOMAIN_NAME,
+    XML_TAG_HOST_NAME,
+    XML_TAG_PORT,
+    XML_TAG_TXT_RECORD
+} xml_tag_name;
+
+struct xml_userdata {
+    StaticServiceGroup *group;
+    StaticService *service;
+    xml_tag_name current_tag;
+    gboolean failed;
+    gchar *buf;
+};
+
+static void XMLCALL xml_start(void *data, const char *el, const char *attr[]) {
+    struct xml_userdata *u = data;
+    
+    g_assert(u);
+
+    if (u->failed)
+        return;
+
+    if (u->current_tag == XML_TAG_INVALID && strcmp(el, "service-group") == 0) {
+
+        if (attr[0])
+            goto invalid_attr;
+
+        u->current_tag = XML_TAG_SERVICE_GROUP;
+    } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "name") == 0) {
+        u->current_tag = XML_TAG_NAME;
+
+        if (attr[0]) {
+            if (strcmp(attr[0], "replace-wildcards") == 0) 
+                u->group->replace_wildcards = strcmp(attr[1], "yes") == 0;
+            else
+                goto invalid_attr;
+        }
+
+        if (attr[2])
+            goto invalid_attr;
+        
+            
+        
+    } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "service") == 0) {
+        if (attr[0])
+            goto invalid_attr;
+
+        g_assert(!u->service);
+        u->service = static_service_new(u->group);
+
+        u->current_tag = XML_TAG_SERVICE;
+    } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "type") == 0) {
+        if (attr[0])
+            goto invalid_attr;
+
+        u->current_tag = XML_TAG_TYPE;
+    } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "domain-name") == 0) {
+        if (attr[0])
+            goto invalid_attr;
+        
+        u->current_tag = XML_TAG_DOMAIN_NAME;
+    } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "host-name") == 0) {
+        if (attr[0])
+            goto invalid_attr;
+        
+        u->current_tag = XML_TAG_HOST_NAME;
+    } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "port") == 0) {
+        if (attr[0])
+            goto invalid_attr;
+        
+        u->current_tag = XML_TAG_PORT;
+    } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "txt-record") == 0) {
+        if (attr[0])
+            goto invalid_attr;
+        
+        u->current_tag = XML_TAG_TXT_RECORD;
+    } else {
+        g_message("%s: parse failure: didn't expect element <%s>.", u->group->filename, el);
+        u->failed = TRUE;
+    }
+
+    return;
+
+invalid_attr:
+    g_message("%s: parse failure: invalid attribute for element <%s>.", u->group->filename, el);
+    u->failed = TRUE;
+    return;
+}
+    
+static void XMLCALL xml_end(void *data, const char *el) {
+    struct xml_userdata *u = data;
+    g_assert(u);
+
+    if (u->failed)
+        return;
+    
+    switch (u->current_tag) {
+        case XML_TAG_SERVICE_GROUP:
+
+            if (!u->group->name || !u->group->services) {
+                g_message("%s: parse failure: service group incomplete.", u->group->filename);
+                u->failed = TRUE;
+                return;
+            }
+            
+            u->current_tag = XML_TAG_INVALID;
+            break;
+
+        case XML_TAG_SERVICE:
+
+            if (u->service->port == 0 || !u->service->type) {
+                g_message("%s: parse failure: service incomplete.", u->group->filename);
+                u->failed = TRUE;
+                return;
+            }
+            
+            u->service = NULL;
+            u->current_tag = XML_TAG_SERVICE_GROUP;
+            break;
+
+        case XML_TAG_NAME:
+            u->current_tag = XML_TAG_SERVICE_GROUP;
+            break;
+
+        case XML_TAG_PORT: {
+            int p;
+            g_assert(u->service);
+            
+            p = u->buf ? atoi(u->buf) : 0;
+
+            if (p <= 0 || p > 0xFFFF) {
+                g_message("%s: parse failure: invalid port specification \"%s\".", u->group->filename, u->buf);
+                u->failed = TRUE;
+                return;
+            }
+
+            u->service->port = (guint16) p;
+
+            u->current_tag = XML_TAG_SERVICE;
+            break;
+        }
+
+        case XML_TAG_TXT_RECORD: {
+            g_assert(u->service);
+            
+            u->service->txt_records = avahi_string_list_add(u->service->txt_records, u->buf ? u->buf : "");
+            u->current_tag = XML_TAG_SERVICE;
+            break;
+        }
+            
+        case XML_TAG_TYPE:
+        case XML_TAG_DOMAIN_NAME:
+        case XML_TAG_HOST_NAME:
+            u->current_tag = XML_TAG_SERVICE;
+            break;
+
+        case XML_TAG_INVALID:
+            ;
+    }
+
+    g_free(u->buf);
+    u->buf = NULL;
+}
+
+static gchar *append_cdata(gchar *t, const gchar *n, int length) {
+    gchar *r, *k;
+    
+    if (!length)
+        return t;
+
+    k = g_strndup(n, length);
+
+    if (t) {
+        r = g_strconcat(t, k, NULL);
+        g_free(k);
+        g_free(t);
+    } else
+        r = k;
+    
+    return r;
+}
+
+static void XMLCALL xml_cdata(void *data, const XML_Char *s, int len) {
+    struct xml_userdata *u = data;
+    g_assert(u);
+
+    if (u->failed)
+        return;
+
+    switch (u->current_tag) {
+        case XML_TAG_NAME:
+            u->group->name = append_cdata(u->group->name, s, len);
+            break;
+            
+        case XML_TAG_TYPE:
+            g_assert(u->service);
+            u->service->type = append_cdata(u->service->type, s, len);
+            break;
+
+        case XML_TAG_DOMAIN_NAME:
+            g_assert(u->service);
+            u->service->domain_name = append_cdata(u->service->domain_name, s, len);
+            break;
+
+        case XML_TAG_HOST_NAME:
+            g_assert(u->service);
+            u->service->host_name = append_cdata(u->service->host_name, s, len);
+            break;
+
+        case XML_TAG_PORT:
+        case XML_TAG_TXT_RECORD:
+            u->buf = append_cdata(u->buf, s, len);
+            break;
+
+        case XML_TAG_SERVICE_GROUP:
+        case XML_TAG_SERVICE:
+        case XML_TAG_INVALID:
+            ;
+    }
+}
+
+static gint static_service_group_load(StaticServiceGroup *g) {
+    XML_Parser parser = NULL;
+    gint fd = -1;
+    struct xml_userdata u;
+    gint r = -1;
+    struct stat st;
+    ssize_t n;
+
+    g_assert(g);
+
+    u.buf = NULL;
+    u.group = g;
+    u.service = NULL;
+    u.current_tag = XML_TAG_INVALID;
+    u.failed = FALSE;
+
+    /* Cleanup old data in this service group, if available */
+    remove_static_service_group_from_server(g);
+    while (g->services)
+        static_service_free(g->services);
+
+    g_free(g->name);
+    g_free(g->chosen_name);
+    g->name = g->chosen_name = NULL;
+    g->replace_wildcards = FALSE;
+    
+    if (!(parser = XML_ParserCreate(NULL))) {
+        g_warning("XML_ParserCreate() failed.");
+        goto finish;
+    }
+
+    if ((fd = open(g->filename, O_RDONLY)) < 0) {
+        g_warning("open(\"%s\", O_RDONLY): %s", g->filename, strerror(errno));
+        goto finish;
+    }
+
+    if (fstat(fd, &st) < 0) {
+        g_warning("fstat(): %s", strerror(errno));
+        goto finish;
+    }
+
+    g->mtime = st.st_mtime;
+    
+    XML_SetUserData(parser, &u);
+
+    XML_SetElementHandler(parser, xml_start, xml_end);
+    XML_SetCharacterDataHandler(parser, xml_cdata);
+
+    do {
+        void *buffer;
+
+#define BUFSIZE (10*1024)
+
+        if (!(buffer = XML_GetBuffer(parser, BUFSIZE))) {
+            g_warning("XML_GetBuffer() failed.");
+            goto finish;
+        }
+
+        if ((n = read(fd, buffer, BUFSIZE)) < 0) {
+            g_warning("read(): %s\n", strerror(errno));
+            goto finish;
+        }
+
+        if (!XML_ParseBuffer(parser, n, n == 0)) {
+            g_warning("XML_ParseBuffer() failed at line %d: %s.\n", XML_GetCurrentLineNumber(parser), XML_ErrorString(XML_GetErrorCode(parser)));
+            goto finish;
+        }
+
+    } while (n != 0);
+
+    if (!u.failed)
+        r = 0;
+
+finish:
+
+    if (fd >= 0)
+        close(fd);
+
+    if (parser)
+        XML_ParserFree(parser);
+
+    g_free(u.buf);
+
+    return r;
+}
+
+static void load_file(gchar *n) {
+    StaticServiceGroup *g;
+    g_assert(n);
+
+    for (g = groups; g; g = g->groups_next)
+        if (strcmp(g->filename, n) == 0)
+            return;
+
+    g = static_service_group_new(n);
+    if (static_service_group_load(g) < 0) {
+        g_warning("Failed to load service group file %s, ignoring.", g->filename);
+        static_service_group_free(g);
+    }
+}
+
+void static_service_load(void) {
+    StaticServiceGroup *g, *n;
+    glob_t globbuf;
+    gchar **p;
+
+    for (g = groups; g; g = n) {
+        struct stat st;
+
+        n = g->groups_next;
+
+        if (stat(g->filename, &st) < 0) {
+
+            if (errno == ENOENT)
+                g_message("Service group file %s vanished, removing seervices.", g->filename);
+            else
+                g_warning("Failed to stat() file %s, ignoring: %s", g->filename, strerror(errno));
+            
+            static_service_group_free(g);
+        } else if (st.st_mtime != g->mtime) {
+            g_message("Service group file %s changed, reloading.", g->filename);
+            
+            if (static_service_group_load(g) < 0) {
+                g_warning("Failed to load service group file %s, removing service.", g->filename);
+                static_service_group_free(g);
+            }
+        }
+    }
+
+    memset(&globbuf, 0, sizeof(globbuf));
+    if (glob(AVAHI_SERVICE_DIRECTORY "/*.service", GLOB_ERR, NULL, &globbuf) != 0)
+        g_warning("glob() failed.\n");
+    else {
+        for (p = globbuf.gl_pathv; *p; p++)
+            load_file(*p);
+        
+        globfree(&globbuf);
+    }
+}
+
+void static_service_free_all(void) {
+    
+    while (groups)
+        static_service_group_free(groups);
+}
+
+void static_service_add_to_server(void) {
+    StaticServiceGroup *g;
+
+    for (g = groups; g; g = g->groups_next)
+        add_static_service_group_to_server(g);
+}
+
+void static_service_remove_from_server(void) {
+    StaticServiceGroup *g;
+
+    for (g = groups; g; g = g->groups_next)
+        remove_static_service_group_from_server(g);
+}