draft/channel-rename: services-arbitrated registered-channel rename

include/capab.h

@@ -45,6 +45,7 @@ enum Capab {
   _CAP(AWAYNOTIFY, 0, "away-notify", 0),
   _CAP(ACCNOTIFY, 0, "account-notify", 0),
   _CAP(SASL, 0, "sasl", 0),
+  _CAP(DRAFT_CHANRENAME, 0, "draft/channel-rename", 0),
 #ifdef USE_SSL
   _CAP(TLS, 0, "tls", 0),
 #endif

include/channel.h

@@ -515,6 +515,16 @@ extern int IsInvited(struct Client* cptr, const void* chptr);
 extern void send_channel_modes(struct Client *cptr, struct Channel *chptr);
 extern char *pretty_mask(char *mask);
 extern char *pretty_extmask(char *mask);
+extern int rename_channel(struct Channel **chptr_p, const char *newname);
+
+/* Pending channel-rename requests (defined in m_rename.c; consumed by the
+ * ACCOUNT A/D reply path in m_account.c and client exit in s_misc.c). */
+struct PendingRename;
+extern struct PendingRename *pending_rename_find(unsigned int cookie);
+extern void pending_rename_complete(struct PendingRename *pr);
+extern void pending_rename_deny(struct PendingRename *pr, const char *reason);
+extern void pending_rename_client_exit(struct Client *cptr);
+
 extern void del_invite(struct Client *cptr, struct Channel *chptr);
 extern void list_set_default(void); /* this belongs elsewhere! */
 

include/client.h

@@ -171,6 +171,7 @@ enum Flag
     FLAG_IPV6,                      /**< server understands P10 IPv6 addrs */
     FLAG_SERVICE,                   /**< server is a service */
     FLAG_OPLEVELS,                  /**< server has oplevels support */
+    FLAG_RENAME_CAPABLE,            /**< server applies and relays RENAME */
     FLAG_GOTID,                     /**< successful ident lookup achieved */
     FLAG_DOID,                      /**< I-lines say must use ident return */
     FLAG_NONL,                      /**< No \n in buffer */
@@ -735,6 +736,8 @@ struct Client {
 #define IsService(x)            HasFlag(x, FLAG_SERVICE)
 /** Return non-zero if the client has oplevels support. */
 #define IsOpLevels(x)           HasFlag(x, FLAG_OPLEVELS)
+/** Return non-zero if the client applies and relays RENAME. */
+#define IsRenameCapable(x)      HasFlag(x, FLAG_RENAME_CAPABLE)
 /** Return non-zero if the client has an account stamp. */
 #define IsAccount(x)            HasFlag(x, FLAG_ACCOUNT)
 /** Return non-zero if the client has set mode +x (hidden host). */
@@ -855,6 +858,8 @@ struct Client {
 #define SetService(x)           SetFlag(x, FLAG_SERVICE)
 /** Mark a client as having oplevels support. */
 #define SetOpLevels(x)          SetFlag(x, FLAG_OPLEVELS)
+/** Mark a client as applying and relaying RENAME. */
+#define SetRenameCapable(x)     SetFlag(x, FLAG_RENAME_CAPABLE)
 /** Mark a client as having an account stamp. */
 #define SetAccount(x)           SetFlag(x, FLAG_ACCOUNT)
 /** Mark a client as having mode +x (hidden host). */

include/handlers.h

@@ -131,6 +131,7 @@ extern int m_protoctl(struct Client*, struct Client*, int, char*[]);
 extern int m_pseudo(struct Client*, struct Client*, int, char*[]);
 extern int m_quit(struct Client*, struct Client*, int, char*[]);
 extern int m_registered(struct Client*, struct Client*, int, char*[]);
+extern int m_rename(struct Client*, struct Client*, int, char*[]);
 extern int m_rules(struct Client*, struct Client*, int, char*[]);
 extern int m_sethost(struct Client*, struct Client*, int, char*[]);
 extern int m_shun(struct Client*, struct Client*, int, char*[]);
@@ -237,6 +238,7 @@ extern int ms_privs(struct Client*, struct Client*, int, char*[]);
 extern int ms_quit(struct Client*, struct Client*, int, char*[]);
 extern int ms_rehash(struct Client*, struct Client*, int, char*[]);
 extern int ms_remove(struct Client*, struct Client*, int, char*[]);
+extern int ms_rename(struct Client*, struct Client*, int, char*[]);
 extern int ms_rping(struct Client*, struct Client*, int, char*[]);
 extern int ms_rpong(struct Client*, struct Client*, int, char*[]);
 extern int ms_rules(struct Client*, struct Client*, int, char*[]);

include/hash.h

@@ -86,6 +86,7 @@ extern int hAddWatch(struct Watch *wptr);
 extern int hRemClient(struct Client *cptr);
 extern int hChangeClient(struct Client *cptr, const char *newname);
 extern int hRemChannel(struct Channel *chptr);
+extern int hChangeChannel(struct Channel *chptr, const char *newname);
 extern int hRemWatch(struct Watch *wptr);
 extern struct Client *hSeekClient(const char *name, int TMask);
 extern struct Channel *hSeekChannel(const char *name);

include/ircd_features.h

@@ -313,6 +313,8 @@ enum Feature {
   FEAT_CAP_away_notify,
   FEAT_CAP_account_notify,
   FEAT_CAP_sasl,
+  FEAT_CAP_draft_channel_rename,
+  FEAT_RENAME_SERVICES,
 #ifdef USE_SSL
   FEAT_CAP_tls,
 #endif

include/msg.h

@@ -336,6 +336,10 @@ struct Client;
 #define TOK_ACCOUNT		"AC"
 #define CMD_ACCOUNT		MSG_ACCOUNT, TOK_ACCOUNT
 
+#define MSG_RENAME	"RENAME"	/* RENA */
+#define TOK_RENAME	"RN"
+#define CMD_RENAME	MSG_RENAME, TOK_RENAME
+
 #define MSG_ASLL               "ASLL"          /* ASLL */
 #define TOK_ASLL               "LL"
 #define CMD_ASLL               MSG_ASLL, TOK_ASLL

include/send.h

@@ -157,4 +157,8 @@ extern void sendto_mode_butone(struct Client *one, struct Client *from, const ch
 extern void vsendto_mode_butone(struct Client *one, struct Client *from, const char *mode,
                            const char *pattern, va_list vl);
 
+/* IRCv3 standard-replies FAIL line (tag-free minimal form) */
+extern void send_fail(struct Client *to, const char *command, const char *code,
+                      const char *context, const char *description);
+
 #endif /* INCLUDED_send_h */

ircd/Makefile.in

@@ -176,6 +176,7 @@ IRCD_SRC = \
 	m_quit.c \
 	m_rehash.c \
 	m_remove.c \
+	m_rename.c \
 	m_reset.c \
 	m_restart.c \
 	m_rping.c \
@@ -888,6 +889,13 @@ m_remove.o: m_remove.c ../config.h ../include/client.h ../include/gline.h \
   ../include/ircd_reply.h ../include/ircd_string.h ../include/msg.h \
   ../include/numeric.h ../include/numnicks.h ../include/send.h \
   ../include/shun.h ../include/zline.h
+m_rename.o: m_rename.c ../config.h ../include/channel.h \
+  ../include/client.h ../include/hash.h ../include/ircd.h \
+  ../include/ircd_events.h ../include/ircd_features.h ../include/ircd_log.h \
+  ../include/ircd_reply.h ../include/ircd_snprintf.h ../include/ircd_string.h \
+  ../include/ircd_alloc.h ../include/list.h ../include/msg.h \
+  ../include/numeric.h ../include/numnicks.h ../include/s_user.h \
+  ../include/send.h
 m_reset.o: m_reset.c ../config.h ../include/client.h ../include/hash.h \
   ../include/ircd.h ../include/ircd_features.h ../include/ircd_log.h \
   ../include/ircd_reply.h ../include/ircd_string.h ../include/numeric.h \

ircd/channel.c

@@ -1842,6 +1842,95 @@ struct Channel *get_channel(struct Client *cptr, char *chname, ChannelGetType fl
   return chptr;
 }
 
+/** Rename a channel.
+ * Updates the channel name in the hash table and channel structure.
+ * Reallocates the channel structure if the new name is longer.
+ *
+ * @param[in,out] chptr_p Pointer to channel pointer. Updated if reallocation occurs.
+ * @param[in] newname New name for the channel.
+ * @return 0 on success, -1 if invalid params, -2 if new name exists.
+ */
+int rename_channel(struct Channel **chptr_p, const char *newname)
+{
+  struct Channel *chptr;
+  size_t oldlen, newlen;
+  struct Channel *newchptr;
+  struct Membership *member;
+  struct SLink *link;
+
+  if (!chptr_p || !*chptr_p || !newname || !*newname)
+    return -1;
+
+  chptr = *chptr_p;
+
+  newlen = strlen(newname);
+  if (newlen > CHANNELLEN)
+    return -1;
+
+  /* Check if new name already exists */
+  if (FindChannel(newname))
+    return -2;
+
+  oldlen = strlen(chptr->chname);
+
+  /* If new name fits in existing allocation, just update in place */
+  if (newlen <= oldlen) {
+    hChangeChannel(chptr, newname);
+    strcpy(chptr->chname, newname);
+    return 0;
+  }
+
+  /* New name is longer - need to reallocate */
+  newchptr = (struct Channel*) MyMalloc(sizeof(struct Channel) + newlen);
+  if (!newchptr)
+    return -1;
+
+  /* Copy all data from old to new */
+  memcpy(newchptr, chptr, sizeof(struct Channel));
+  strcpy(newchptr->chname, newname);
+
+  /* Update hash table */
+  hRemChannel(chptr);
+  hAddChannel(newchptr);
+
+  /* Update global linked list */
+  if (chptr->prev)
+    chptr->prev->next = newchptr;
+  else
+    GlobalChannelList = newchptr;
+  if (chptr->next)
+    chptr->next->prev = newchptr;
+
+  /* Update all membership pointers */
+  for (member = newchptr->members; member; member = member->next_member)
+    member->channel = newchptr;
+
+  /* Update user invite lists that point to this channel */
+  for (link = newchptr->invites; link; link = link->next) {
+    struct Client *cptr = link->value.cptr;
+    struct SLink *inv;
+    /* Find and update user's invite pointer to this channel */
+    for (inv = cli_user(cptr)->invited; inv; inv = inv->next) {
+      if (inv->value.chptr == chptr) {
+        inv->value.chptr = newchptr;
+        break;
+      }
+    }
+  }
+
+  /* Update destruct event if pending */
+  if (newchptr->destruct_event)
+    newchptr->destruct_event->chptr = newchptr;
+
+  /* Free old channel structure */
+  MyFree(chptr);
+
+  /* Update caller's pointer */
+  *chptr_p = newchptr;
+
+  return 0;
+}
+
 /** invite a user to a channel.
  *
  * Adds an invite for a user to a channel.  Limits the number of invites

ircd/hash.c

@@ -214,6 +214,23 @@ int hRemChannel(struct Channel *chptr)
   return -1;
 }
 
+/** Rename a channel in the hash table.
+ * @param[in] chptr Channel whose name is changing.
+ * @param[in] newname New name for channel.
+ * @return Zero on success.
+ */
+int hChangeChannel(struct Channel *chptr, const char *newname)
+{
+  HASHREGS newhash = strhash(newname);
+
+  assert(0 != chptr);
+  hRemChannel(chptr);
+
+  chptr->hnext = channelTable[newhash];
+  channelTable[newhash] = chptr;
+  return 0;
+}
+
 /** Find a client by name, filtered by status mask.
  * If a client is found, it is moved to the top of its hash bucket.
  * @param[in] name Client name to search for.

ircd/ircd.c

@@ -768,6 +768,10 @@ int main(int argc, char **argv) {
 
   hAddClient(&me);
   SetIPv6(&me);
+  /* We advertise the 'r' (rename-capable) SERVER flag on our own SERVER
+   * lines; mirror it locally so scans over GlobalClientList (which
+   * includes &me) see this server as rename-capable too. */
+  SetRenameCapable(&me);
 
   write_pidfile();
   init_counters();

ircd/ircd_features.c

@@ -796,6 +796,12 @@ static struct FeatureDesc {
   F_B(CAP_away_notify, 0, 1, 0),
   F_B(CAP_account_notify, 0, 1, 0),
   F_B(CAP_sasl, 0, 1, 0),
+  F_B(CAP_draft_channel_rename, 0, 0, 0),
+  /* Off by default: only a services build that disambiguates RENAME
+   * requests from account-stamp notifications on the AC 'R' subcommand
+   * (see the protocol-history comment in m_rename.c) should have this
+   * enabled. */
+  F_B(RENAME_SERVICES, 0, 0, 0),
 #ifdef USE_SSL
   F_B(CAP_tls, 0, 1, 0),
 #endif

ircd/m_account.c

@@ -80,6 +80,7 @@
  */
 #include "config.h"
 
+#include "channel.h"
 #include "client.h"
 #include "ircd.h"
 #include "ircd_alloc.h"
@@ -241,12 +242,40 @@ int ms_account(struct Client* cptr, struct Client* sptr, int parc,
                       parv[1], parv[2], parv[3], parv[4], parv[5]);
       return 0;
     } else if (type == 'A' || type == 'D') {
-      /* LOC Replies (A=accept, D=deny) */
-      if (parc < 4)
+      /* LOC Replies (A=accept, D=deny) or Rename Permission Replies */
+      if (parc < 3)
         return need_more_params(sptr, "ACCOUNT");
 
-      if (!(acptr = FindNServer(parv[1])))
-        return 0; /* target not online, ignore */
+      /* Rename reply carries the explicit RENAME discriminator (parv[3]);
+       * route by cookie without FindNServer so a decimal cookie can't
+       * alias a server numeric (F2). */
+      if (parc > 3 && !ircd_strcmp(parv[3], "RENAME")) {
+        unsigned int cookie = atoi(parv[1]);
+        struct PendingRename *pr = pending_rename_find(cookie);
+
+        if (pr) {
+          if (type == 'A') {
+            Debug((DEBUG_DEBUG, "ACCOUNT rename allow cookie=%u", cookie));
+            pending_rename_complete(pr);
+          } else {
+            /* Deny response: parv[4] contains the reason (trailing param) */
+            const char *reason = (parc > 4) ? parv[4] : "Permission denied";
+            Debug((DEBUG_DEBUG, "ACCOUNT rename deny cookie=%u reason=%s", cookie, reason));
+            pending_rename_deny(pr, reason);
+          }
+        }
+        return 0;
+      }
+
+      /* First check if this is a server numeric (LOC reply) */
+      acptr = FindNServer(parv[1]);
+
+      if (!acptr)
+        return 0; /* unknown numeric - ignore */
+
+      /* LOC reply - need at least 4 params */
+      if (parc < 4)
+        return need_more_params(sptr, "ACCOUNT");
 
       if (!IsMe(acptr)) {
         /* in-transit message, forward it */

ircd/m_cap.c

@@ -62,6 +62,7 @@ static struct capabilities {
   _CAP(AWAYNOTIFY, 0, "away-notify", FEAT_CAP_away_notify),
   _CAP(ACCNOTIFY, 0, "account-notify", FEAT_CAP_account_notify),
   _CAP(SASL, 0, "sasl", FEAT_CAP_sasl),
+  _CAP(DRAFT_CHANRENAME, 0, "draft/channel-rename", FEAT_CAP_draft_channel_rename),
 #ifdef USE_SSL
   _CAP(TLS, 0, "tls", FEAT_CAP_tls),
 #endif