--- /dev/null
+/*
+ * IRC - Internet Relay Chat, ircd/m_cap.c
+ * Copyright (C) 2004 Kevin L. Mitchell <klmitch@mit.edu>
+ *
+ * See file AUTHORS in IRC package for additional names of
+ * the programmers.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 1, or (at your option)
+ * any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+/** @file
+ * @brief Capability negotiation commands
+ * @version $Id$
+ */
+
+#include "config.h"
+
+#include "client.h"
+#include "ircd.h"
+#include "ircd_chattr.h"
+#include "ircd_log.h"
+#include "ircd_reply.h"
+#include "ircd_snprintf.h"
+#include "ircd_string.h"
+#include "msg.h"
+#include "numeric.h"
+#include "send.h"
+#include "s_auth.h"
+#include "s_user.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+typedef int (*bqcmp)(const void *, const void *);
+
+static struct capabilities {
+ enum Capab cap;
+ char *capstr;
+ unsigned long flags;
+ char *name;
+ int namelen;
+} capab_list[] = {
+#define _CAP(cap, flags, name) \
+ { CAP_ ## cap, #cap, (flags), (name), sizeof(name) - 1 }
+ CAPLIST
+#undef _CAP
+};
+
+#define CAPAB_LIST_LEN (sizeof(capab_list) / sizeof(struct capabilities))
+
+static int
+capab_sort(const struct capabilities *cap1, const struct capabilities *cap2)
+{
+ return ircd_strcmp(cap1->name, cap2->name);
+}
+
+static int
+capab_search(const char *key, const struct capabilities *cap)
+{
+ const char *rb = cap->name;
+ while (ToLower(*key) == ToLower(*rb)) /* walk equivalent part of strings */
+ if (!*key++) /* hit the end, all right... */
+ return 0;
+ else /* OK, let's move on... */
+ rb++;
+
+ /* If the character they differ on happens to be a space, and it happens
+ * to be the same length as the capability name, then we've found a
+ * match; otherwise, return the difference of the two.
+ */
+ return (IsSpace(*key) && !*rb) ? 0 : (ToLower(*key) - ToLower(*rb));
+}
+
+static struct capabilities *
+find_cap(const char **caplist_p, int *neg_p)
+{
+ static int inited = 0;
+ const char *caplist = *caplist_p;
+ struct capabilities *cap = 0;
+
+ *neg_p = 0; /* clear negative flag... */
+
+ if (!inited) { /* First, let's sort the array... */
+ qsort(capab_list, CAPAB_LIST_LEN, sizeof(struct capabilities),
+ (bqcmp)capab_sort);
+ inited++; /* remember that we've done this step... */
+ }
+
+ /* Next, find first non-whitespace character... */
+ while (*caplist && IsSpace(*caplist))
+ caplist++;
+
+ /* We are now at the beginning of an element of the list; is it negative? */
+ if (*caplist == '-') {
+ caplist++; /* yes; step past the flag... */
+ *neg_p = 1; /* remember that it is negative... */
+ }
+
+ /* OK, now see if we can look up the capability... */
+ if (*caplist) {
+ if (!(cap = (struct capabilities *)bsearch(caplist, capab_list,
+ CAPAB_LIST_LEN,
+ sizeof(struct capabilities),
+ (bqcmp)capab_search))) {
+ /* Couldn't find the capability; advance to first whitespace character */
+ while (*caplist && !IsSpace(*caplist))
+ caplist++;
+ } else
+ caplist += cap->namelen; /* advance to end of capability name */
+ }
+
+ assert(caplist != *caplist_p || !*caplist); /* we *must* advance */
+
+ /* move ahead in capability list string--or zero pointer if we hit end */
+ *caplist_p = *caplist ? caplist : 0;
+
+ return cap; /* and return the capability (if any) */
+}
+
+/** Send a CAP \a subcmd list of capability changes to \a sptr.
+ * If more than one line is necessary, each line before the last has
+ * an added "*" parameter before that line's capability list.
+ * @param[in] sptr Client receiving capability list.
+ * @param[in] set Capabilities to show as set (with ack and sticky modifiers).
+ * @param[in] rem Capabalities to show as removed (with no other modifier).
+ * @param[in] subcmd Name of capability subcommand.
+ */
+static int
+send_caplist(struct Client *sptr, const struct CapSet *set,
+ const struct CapSet *rem, const char *subcmd)
+{
+ char capbuf[BUFSIZE] = "", pfx[16];
+ struct MsgBuf *mb;
+ int i, loc, len, flags, pfx_len;
+
+ /* set up the buffer for the final LS message... */
+ mb = msgq_make(sptr, "%:#C " MSG_CAP " %s :", &me, subcmd);
+
+ for (i = 0, loc = 0; i < CAPAB_LIST_LEN; i++) {
+ flags = capab_list[i].flags;
+ /* This is a little bit subtle, but just involves applying de
+ * Morgan's laws to the obvious check: We must display the
+ * capability if (and only if) it is set in \a rem or \a set, or
+ * if both are null and the capability is hidden.
+ */
+ if (!(rem && CapHas(rem, capab_list[i].cap))
+ && !(set && CapHas(set, capab_list[i].cap))
+ && (rem || set || (flags & CAPFL_HIDDEN)))
+ continue;
+
+ /* Build the prefix (space separator and any modifiers needed). */
+ pfx_len = 0;
+ if (loc)
+ pfx[pfx_len++] = ' ';
+ if (rem && CapHas(rem, capab_list[i].cap))
+ pfx[pfx_len++] = '-';
+ else {
+ if (flags & CAPFL_PROTO)
+ pfx[pfx_len++] = '~';
+ if (flags & CAPFL_STICKY)
+ pfx[pfx_len++] = '=';
+ }
+ pfx[pfx_len] = '\0';
+
+ len = capab_list[i].namelen + pfx_len; /* how much we'd add... */
+ if (msgq_bufleft(mb) < loc + len + 2) { /* would add too much; must flush */
+ sendcmdto_one(&me, CMD_CAP, sptr, "%s * :%s", subcmd, capbuf);
+ capbuf[(loc = 0)] = '\0'; /* re-terminate the buffer... */
+ }
+
+ loc += ircd_snprintf(0, capbuf + loc, sizeof(capbuf) - loc, "%s%s",
+ pfx, capab_list[i].name);
+ }
+
+ msgq_append(0, mb, "%s", capbuf); /* append capabilities to the final cmd */
+ send_buffer(sptr, mb, 0); /* send them out... */
+ msgq_clean(mb); /* and release the buffer */
+
+ return 0; /* convenience return */
+}
+
+static int
+cap_ls(struct Client *sptr, const char *caplist)
+{
+ if (IsUnknown(sptr)) /* registration hasn't completed; suspend it... */
+ auth_cap_start(cli_auth(sptr));
+ return send_caplist(sptr, 0, 0, "LS"); /* send list of capabilities */
+}
+
+static int
+cap_req(struct Client *sptr, const char *caplist)
+{
+ const char *cl = caplist;
+ struct capabilities *cap;
+ struct CapSet set, rem;
+ struct CapSet cs = *cli_capab(sptr); /* capability set */
+ struct CapSet as = *cli_active(sptr); /* active set */
+ int neg;
+
+ if (IsUnknown(sptr)) /* registration hasn't completed; suspend it... */
+ auth_cap_start(cli_auth(sptr));
+
+ memset(&set, 0, sizeof(set));
+ memset(&rem, 0, sizeof(rem));
+ while (cl) { /* walk through the capabilities list... */
+ if (!(cap = find_cap(&cl, &neg)) /* look up capability... */
+ || (!neg && (cap->flags & CAPFL_PROHIBIT)) /* is it prohibited? */
+ || (neg && (cap->flags & CAPFL_STICKY))) { /* is it sticky? */
+ sendcmdto_one(&me, CMD_CAP, sptr, "NAK :%s", caplist);
+ return 0; /* can't complete requested op... */
+ }
+
+ if (neg) { /* set or clear the capability... */
+ CapSet(&rem, cap->cap);
+ CapClr(&set, cap->cap);
+ CapClr(&cs, cap->cap);
+ if (!(cap->flags & CAPFL_PROTO))
+ CapClr(&as, cap->cap);
+ } else {
+ CapClr(&rem, cap->cap);
+ CapSet(&set, cap->cap);
+ CapSet(&cs, cap->cap);
+ if (!(cap->flags & CAPFL_PROTO))
+ CapSet(&as, cap->cap);
+ }
+ }
+
+ /* Notify client of accepted changes and copy over results. */
+ send_caplist(sptr, &set, &rem, "ACK");
+ *cli_capab(sptr) = cs;
+ *cli_active(sptr) = as;
+
+ return 0;
+}
+
+static int
+cap_ack(struct Client *sptr, const char *caplist)
+{
+ const char *cl = caplist;
+ struct capabilities *cap;
+ int neg;
+
+ /* Coming from the client, this generally indicates that the client
+ * is using a new backwards-incompatible protocol feature. As such,
+ * it does not require further response from the server.
+ */
+ while (cl) { /* walk through the capabilities list... */
+ if (!(cap = find_cap(&cl, &neg)) || /* look up capability... */
+ (neg ? HasCap(sptr, cap->cap) : !HasCap(sptr, cap->cap))) /* uh... */
+ continue;
+
+ if (neg) { /* set or clear the active capability... */
+ if (cap->flags & CAPFL_STICKY)
+ continue; /* but don't clear sticky capabilities */
+ CapClr(cli_active(sptr), cap->cap);
+ } else {
+ if (cap->flags & CAPFL_PROHIBIT)
+ continue; /* and don't set prohibited ones */
+ CapSet(cli_active(sptr), cap->cap);
+ }
+ }
+
+ return 0;
+}
+
+static int
+cap_clear(struct Client *sptr, const char *caplist)
+{
+ struct CapSet cleared;
+ struct capabilities *cap;
+ unsigned int ii;
+
+ /* XXX: If we ever add a capab list sorted by capab value, it would
+ * be good cache-wise to use it here. */
+ memset(&cleared, 0, sizeof(cleared));
+ for (ii = 0; ii < CAPAB_LIST_LEN; ++ii) {
+ cap = &capab_list[ii];
+ /* Only clear active non-sticky capabilities. */
+ if (!HasCap(sptr, cap->cap) || (cap->flags & CAPFL_STICKY))
+ continue;
+ CapSet(&cleared, cap->cap);
+ CapClr(cli_capab(sptr), cap->cap);
+ if (!(cap->flags & CAPFL_PROTO))
+ CapClr(cli_active(sptr), cap->cap);
+ }
+ send_caplist(sptr, 0, &cleared, "ACK");
+
+ return 0;
+}
+
+static int
+cap_end(struct Client *sptr, const char *caplist)
+{
+ if (!IsUnknown(sptr)) /* registration has completed... */
+ return 0; /* so just ignore the message... */
+
+ return auth_cap_done(cli_auth(sptr));
+}
+
+static int
+cap_list(struct Client *sptr, const char *caplist)
+{
+ /* Send the list of the client's capabilities */
+ return send_caplist(sptr, cli_capab(sptr), 0, "LIST");
+}
+
+static struct subcmd {
+ char *cmd;
+ int (*proc)(struct Client *sptr, const char *caplist);
+} cmdlist[] = {
+ { "ACK", cap_ack },
+ { "CLEAR", cap_clear },
+ { "END", cap_end },
+ { "LIST", cap_list },
+ { "LS", cap_ls },
+ { "NAK", 0 },
+ { "REQ", cap_req }
+};
+
+static int
+subcmd_search(const char *cmd, const struct subcmd *elem)
+{
+ return ircd_strcmp(cmd, elem->cmd);
+}
+
+/** Handle a capability request or response from a client.
+ * @param[in] cptr Client that sent us the message.
+ * @param[in] sptr Original source of message.
+ * @param[in] parc Number of arguments.
+ * @param[in] parv Argument vector.
+ * @see \ref m_functions
+ */
+int
+m_cap(struct Client* cptr, struct Client* sptr, int parc, char* parv[])
+{
+ char *subcmd, *caplist = 0;
+ struct subcmd *cmd;
+
+ if (parc < 2) /* a subcommand is required */
+ return 0;
+ subcmd = parv[1];
+ if (parc > 2) /* a capability list was provided */
+ caplist = parv[2];
+
+ /* find the subcommand handler */
+ if (!(cmd = (struct subcmd *)bsearch(subcmd, cmdlist,
+ sizeof(cmdlist) / sizeof(struct subcmd),
+ sizeof(struct subcmd),
+ (bqcmp)subcmd_search)))
+ return send_reply(sptr, ERR_UNKNOWNCAPCMD, subcmd);
+
+ /* then execute it... */
+ return cmd->proc ? (cmd->proc)(sptr, caplist) : 0;
+}
projects / ircu2.10.12-pk.git / blobdiff