path: root/net/ser/files/patch-modules::nathelper::nathelper.c

$FreeBSD$

--- modules/nathelper/nathelper.c.orig
+++ modules/nathelper/nathelper.c
@@ -110,14 +110,42 @@
  *
  * 2004-03-22  Fix get_body position (should be called before get_callid)
  *                 (andrei)
+ *
  * 2004-03-24  Fix newport for null ip address case (e.g onhold re-INVITE)
  *                 (andrei)
- * 2004-09-30  added received port != via port test (andrei) 
+ *
+ * 2004-09-30  added received port != via port test (andrei)
+ *
  * 2004-10-10   force_socket option introduced (jiri)
+ * 2004-12-21  support for multiple medias added (netch)
+ * 2005-01-18  proxying on protocol type (RTP/AVP, udp, udptl), not
+ *     media type. (sobomax,netch)
+ *
+ * 2005-02-24  Added support for using more than one rtp proxy, in which
+ *     case traffic will be distributed evenly among them. In addition,
+ *     each such proxy can be assigned a weight, which will specify
+ *     which share of the traffic should be placed to this particular
+ *     proxy.
+ *
+ *     Introduce failover mechanism, so that if SER detects that one
+ *     of many proxies is no longer available it temporarily decreases
+ *     its weight to 0, so that no traffic will be assigned to it.
+ *     Such "disabled" proxies are periodically checked to see if they
+ *     are back to normal in which case respective weight is restored
+ *     resulting in traffic being sent to that proxy again.
+ *
+ *     Those features can be enabled by specifying more than one "URI"
+ *     in the rtpproxy_sock parameter, optionally followed by the weight,
+ *     which if absent is assumed to be 1, for example:
  *
+ *     rtpproxy_sock="unix:/foo/bar=4 udp:1.2.3.4:3456=3 udp:5.6.7.8:5432=1"
+ *
+ * 2005-03-24  music-on-hold implemented (netch)
  */
 
 #include "nhelpr_funcs.h"
+#include "nathelper.h"
+#include "../../action.h"
 #include "../../flags.h"
 #include "../../sr_module.h"
 #include "../../dprint.h"
@@ -127,6 +155,7 @@
 #include "../../forward.h"
 #include "../../mem/mem.h"
 #include "../../parser/parse_from.h"
+#include "../../parser/parse_hostport.h"
 #include "../../parser/parse_to.h"
 #include "../../parser/parse_uri.h"
 #include "../../parser/parser_f.h"
@@ -171,39 +200,30 @@
 #define    NAT_UAC_TEST_S_1918 0x08
 #define    NAT_UAC_TEST_RPORT  0x10
 
-/* Handy macros */
-#define    STR2IOVEC(sx, ix)   {(ix).iov_base = (sx).s; (ix).iov_len = (sx).len;}
-
 /* Supported version of the RTP proxy command protocol */
 #define    SUP_CPROTOVER   20040107
+/* Required additional version of the RTP proxy command protocol */
+#define    REQ_CPROTOVER   "20050322"
 #define    CPORT       "22222"
 
 static int nat_uac_test_f(struct sip_msg* msg, char* str1, char* str2);
 static int fix_nated_contact_f(struct sip_msg *, char *, char *);
 static int fix_nated_sdp_f(struct sip_msg *, char *, char *);
-static int extract_mediaip(str *, str *, int *);
-static int extract_mediaport(str *, str *);
-static int alter_mediaip(struct sip_msg *, str *, str *, int, str *, int, int);
-static int alter_mediaport(struct sip_msg *, str *, str *, str *, int);
+static int fixate_sdp_f(struct sip_msg *, char *, char *);
 static char *gencookie();
-static int rtpp_test(int, int);
-static char *send_rtpp_command(struct iovec *, int);
+static int rtpp_test(struct rtpp_node*, int, int);
 static int unforce_rtp_proxy_f(struct sip_msg *, char *, char *);
 static int force_rtp_proxy0_f(struct sip_msg *, char *, char *);
 static int force_rtp_proxy1_f(struct sip_msg *, char *, char *);
 static int force_rtp_proxy2_f(struct sip_msg *, char *, char *);
 static int fix_nated_register_f(struct sip_msg *, char *, char *);
 static int add_rcv_param_f(struct sip_msg *, char *, char *);
+static int rewrite_from_from_f(struct sip_msg *, char *, char *);
 
-static void timer(unsigned int, void *);
 inline static int fixup_str2int(void**, int);
 static int mod_init(void);
 static int child_init(int);
 
-static usrloc_api_t ul;
-
-static int cblen = 0;
-static int natping_interval = 0;
 struct socket_info* force_socket = 0;
 
 
@@ -218,27 +238,51 @@
    {NULL, 0, 0}
 };
 
-/*
- * If this parameter is set then the natpinger will ping only contacts
- * that have the NAT flag set in user location database
- */
-static int ping_nated_only = 0;
-static const char sbuf[4] = {0, 0, 0, 0};
-static char *rtpproxy_sock = "unix:/var/run/rtpproxy.sock";
+static str sup_ptypes[] = {
+   {.s = "udp", .len = 3},
+   {.s = "udptl", .len = 5},
+   {.s = "rtp/avp", .len = 7},
+   {.s = NULL, .len = 0}
+};
+
+static char *rtpproxy_sock = "unix:/var/run/rtpproxy.sock"; /* list */
 static char *force_socket_str = 0;
 static int rtpproxy_disable = 0;
 static int rtpproxy_disable_tout = 60;
 static int rtpproxy_retr = 5;
 static int rtpproxy_tout = 1;
-static int umode = 0;
-static int controlfd;
 static pid_t mypid;
 static unsigned int myseqn = 0;
-static int rcv_avp_no=42;
+static int rcv_avp_no = 42;
+char *pname_audio = "-";
+char *pname_video = "-";
+char *codecs_audio = "-";
+char *codecs_video = "-";
+
+struct rtpp_head {
+   struct rtpp_node    *rn_first;
+   struct rtpp_node    *rn_last;
+};
+
+struct rtpp_node {
+   char            *rn_url;    /* unparsed, deletable */
+   int         rn_umode;
+   char            *rn_address;    /* substring of rn_url */
+   int         rn_fd;      /* control fd */
+   int         rn_disabled;    /* found unaccessible? */
+   unsigned        rn_weight;  /* for load balancing */
+   int         rn_recheck_ticks;
+   struct rtpp_node    *rn_next;
+};
+
+/* RTP proxy balancing list */
+static struct rtpp_head rtpp_list;
+static int rtpp_node_count = 0;
 
 static cmd_export_t cmds[] = {
    {"fix_nated_contact",  fix_nated_contact_f,    0, 0,             REQUEST_ROUTE | ONREPLY_ROUTE },
    {"fix_nated_sdp",      fix_nated_sdp_f,        1, fixup_str2int, REQUEST_ROUTE | ONREPLY_ROUTE | FAILURE_ROUTE },
+   {"fixate_sdp",         fixate_sdp_f,           0, 0,             REQUEST_ROUTE | ONREPLY_ROUTE },
    {"unforce_rtp_proxy",  unforce_rtp_proxy_f,    0, 0,             REQUEST_ROUTE | ONREPLY_ROUTE | FAILURE_ROUTE },
    {"force_rtp_proxy",    force_rtp_proxy0_f,     0, 0,             REQUEST_ROUTE | ONREPLY_ROUTE },
    {"force_rtp_proxy",    force_rtp_proxy1_f,     1, 0,             REQUEST_ROUTE | ONREPLY_ROUTE },
@@ -246,11 +290,16 @@
    {"nat_uac_test",       nat_uac_test_f,         1, fixup_str2int, REQUEST_ROUTE | ONREPLY_ROUTE | FAILURE_ROUTE },
    {"fix_nated_register", fix_nated_register_f,   0, 0,             REQUEST_ROUTE },
    {"add_rcv_param",      add_rcv_param_f,        0, 0,             REQUEST_ROUTE },
+   {"rewrite_from_from",  rewrite_from_from_f,    0, 0,             REQUEST_ROUTE | ONREPLY_ROUTE },
+   {"is_hold",     is_hold_f,         0, 0,         REQUEST_ROUTE | ONREPLY_ROUTE },
+   {"start_moh",       start_moh_f,           0, 0,         REQUEST_ROUTE | ONREPLY_ROUTE },
+   {"stop_moh",        stop_moh_f,        0, 0,         REQUEST_ROUTE | ONREPLY_ROUTE },
    {0, 0, 0, 0, 0}
 };
 
 static param_export_t params[] = {
    {"natping_interval",      INT_PARAM, &natping_interval      },
+   {"natping_method",    STR_PARAM, &natping_method        },
    {"ping_nated_only",       INT_PARAM, &ping_nated_only       },
    {"rtpproxy_sock",         STR_PARAM, &rtpproxy_sock         },
    {"rtpproxy_disable",      INT_PARAM, &rtpproxy_disable      },
@@ -259,6 +308,10 @@
    {"rtpproxy_tout",         INT_PARAM, &rtpproxy_tout         },
    {"received_avp",          INT_PARAM, &rcv_avp_no            },
    {"force_socket",          STR_PARAM, &force_socket_str      },
+   {"pname_audio",       STR_PARAM, &pname_audio       },
+   {"pname_video",       STR_PARAM, &pname_video       },
+   {"codecs_audio",      STR_PARAM, &codecs_audio      },
+   {"codecs_video",      STR_PARAM, &codecs_video      },
    {0, 0, 0}
 };
 
@@ -277,8 +330,6 @@
 mod_init(void)
 {
    int i;
-   char *cp;
-   bind_usrloc_t bind_usrloc;
    struct in_addr addr;
    str socket_str;
 
@@ -288,18 +339,9 @@
        force_socket=grep_sock_info(&socket_str,0,0);
    }
 
-   if (natping_interval > 0) {
-       bind_usrloc = (bind_usrloc_t)find_export("ul_bind_usrloc", 1, 0);
-       if (!bind_usrloc) {
-           LOG(L_ERR, "nathelper: Can't find usrloc module\n");
-           return -1;
-       }
-
-       if (bind_usrloc(&ul) < 0) {
-           return -1;
-       }
-
-       register_timer(timer, NULL, natping_interval);
+   if (natpinger_init() < 0) {
+       LOG(L_ERR, "nathelper: natpinger_init() failed\n");
+       return -1;
    }
 
    /* Prepare 1918 networks list */
@@ -309,25 +351,72 @@
        nets_1918[i].netaddr = ntohl(addr.s_addr) & nets_1918[i].mask;
    }
 
+   memset(&rtpp_list, 0, sizeof(rtpp_list));
+   rtpp_node_count = 0;
    if (rtpproxy_disable == 0) {
-       /* Make rtpproxy_sock writable */
-       cp = pkg_malloc(strlen(rtpproxy_sock) + 1);
-       if (cp == NULL) {
-           LOG(L_ERR, "nathelper: Can't allocate memory\n");
-           return -1;
-       }
-       strcpy(cp, rtpproxy_sock);
-       rtpproxy_sock = cp;
+       /* Make rtp proxies list. */
+       char *p, *p1, *p2, *plim;
 
-       if (strncmp(rtpproxy_sock, "udp:", 4) == 0) {
-           umode = 1;
-           rtpproxy_sock += 4;
-       } else if (strncmp(rtpproxy_sock, "udp6:", 5) == 0) {
-           umode = 6;
-           rtpproxy_sock += 5;
-       } else if (strncmp(rtpproxy_sock, "unix:", 5) == 0) {
-           umode = 0;
-           rtpproxy_sock += 5;
+       p = rtpproxy_sock;
+       plim = p + strlen(p);
+       for(;;) {
+           struct rtpp_node *pnode;
+           int weight;
+
+           weight = 1;
+           while (*p && isspace(*p))
+               ++p;
+           if (p >= plim)
+               break;
+           p1 = p;
+           while (*p && !isspace(*p))
+               ++p;
+           if (p <= p1)
+               break; /* may happen??? */
+           /* Have weight specified? If yes, scan it */
+           p2 = memchr(p1, '=', p - p1);
+           if (p2 != NULL) {
+               weight = strtoul(p2 + 1, NULL, 10);
+           } else {
+               p2 = p;
+           }
+           pnode = pkg_malloc(sizeof(struct rtpp_node));
+           if (pnode == NULL) {
+               LOG(L_ERR, "nathelper: Can't allocate memory\n");
+               return -1;
+           }
+           memset(pnode, 0, sizeof(*pnode));
+           pnode->rn_recheck_ticks = 0;
+           pnode->rn_weight = weight;
+           pnode->rn_umode = 0;
+           pnode->rn_fd = -1;
+           pnode->rn_disabled = 0;
+           pnode->rn_url = pkg_malloc(p2 - p1 + 1);
+           if (pnode->rn_url == NULL) {
+               LOG(L_ERR, "nathelper: Can't allocate memory\n");
+               return -1;
+           }
+           memmove(pnode->rn_url, p1, p2 - p1);
+           pnode->rn_url[p2 - p1] = 0;
+           if (rtpp_list.rn_first == NULL) {
+               rtpp_list.rn_first = pnode;
+           } else {
+               rtpp_list.rn_last->rn_next = pnode;
+           }
+           rtpp_list.rn_last = pnode;
+           ++rtpp_node_count;
+           /* Leave only address in rn_address */
+           pnode->rn_address = pnode->rn_url;
+           if (strncmp(pnode->rn_address, "udp:", 4) == 0) {
+               pnode->rn_umode = 1;
+               pnode->rn_address += 4;
+           } else if (strncmp(pnode->rn_address, "udp6:", 5) == 0) {
+               pnode->rn_umode = 6;
+               pnode->rn_address += 5;
+           } else if (strncmp(pnode->rn_address, "unix:", 5) == 0) {
+               pnode->rn_umode = 0;
+               pnode->rn_address += 5;
+           }
        }
    }
 
@@ -340,52 +429,66 @@
    int n;
    char *cp;
    struct addrinfo hints, *res;
+   struct rtpp_node *pnode;
 
-   if (rtpproxy_disable == 0) {
-       mypid = getpid();
-       if (umode != 0) {
-           cp = strrchr(rtpproxy_sock, ':');
-           if (cp != NULL) {
-               *cp = '\0';
-               cp++;
-           }
-           if (cp == NULL || *cp == '\0')
-               cp = CPORT;
+   /* Iterate known RTP proxies - create sockets */
+   mypid = getpid();
+   for (pnode = rtpp_list.rn_first; pnode != NULL; pnode = pnode->rn_next) {
+       char *old_colon;
 
-           memset(&hints, 0, sizeof(hints));
-           hints.ai_flags = 0;
-           hints.ai_family = (umode == 6) ? AF_INET6 : AF_INET;
-           hints.ai_socktype = SOCK_DGRAM;
-           if ((n = getaddrinfo(rtpproxy_sock, cp, &hints, &res)) != 0) {
-               LOG(L_ERR, "nathelper: getaddrinfo: %s\n", gai_strerror(n));
-               return -1;
-           }
+       if (pnode->rn_umode == 0)
+           goto rptest;
+       /*
+        * This is UDP or UDP6. Detect host and port; lookup host;
+        * do connect() in order to specify peer address
+        */
+       old_colon = cp = strrchr(pnode->rn_address, ':');
+       if (cp != NULL) {
+           old_colon = cp;
+           *cp = '\0';
+           cp++;
+       }
+       if (cp == NULL || *cp == '\0')
+           cp = CPORT;
 
-           controlfd = socket((umode == 6) ? AF_INET6 : AF_INET, SOCK_DGRAM, 0);
-           if (controlfd == -1) {
-               LOG(L_ERR, "nathelper: can't create socket\n");
-               freeaddrinfo(res);
-               return -1;
-           }
+       memset(&hints, 0, sizeof(hints));
+       hints.ai_flags = 0;
+       hints.ai_family = (pnode->rn_umode == 6) ? AF_INET6 : AF_INET;
+       hints.ai_socktype = SOCK_DGRAM;
+       if ((n = getaddrinfo(pnode->rn_address, cp, &hints, &res)) != 0) {
+           LOG(L_ERR, "nathelper: getaddrinfo: %s\n", gai_strerror(n));
+           return -1;
+       }
+       if (old_colon)
+           *old_colon = ':'; /* restore rn_address */
 
-           if (connect(controlfd, res->ai_addr, res->ai_addrlen) == -1) {
-               LOG(L_ERR, "nathelper: can't connect to a RTP proxy\n");
-               close(controlfd);
-               freeaddrinfo(res);
-               return -1;
-           }
+       pnode->rn_fd = socket((pnode->rn_umode == 6)
+           ? AF_INET6 : AF_INET, SOCK_DGRAM, 0);
+       if (pnode->rn_fd == -1) {
+           LOG(L_ERR, "nathelper: can't create socket\n");
            freeaddrinfo(res);
+           return -1;
        }
 
-       rtpproxy_disable = rtpp_test(0, 1);
-   } else {
-       rtpproxy_disable_tout = -1;
+       if (connect(pnode->rn_fd, res->ai_addr, res->ai_addrlen) == -1) {
+           LOG(L_ERR, "nathelper: can't connect to a RTP proxy\n");
+           close(pnode->rn_fd);
+           pnode->rn_fd = -1;
+           freeaddrinfo(res);
+           return -1;
+       }
+       freeaddrinfo(res);
+rptest:
+       pnode->rn_disabled = rtpp_test(pnode, 0, 1);
    }
 
+   if (rtpproxy_disable)
+       rtpproxy_disable_tout = -1;
+
    return 0;
 }
 
-static int
+int
 isnulladdr(str *sx, int pf)
 {
    char *cp;
@@ -440,7 +543,7 @@
  * assumes the to header is already parsed, so
  * make sure it really is before calling this function
  */
-static inline int
+int
 get_to_tag(struct sip_msg* _m, str* _tag)
 {
 
@@ -463,7 +566,7 @@
 /*
  * Extract tag from From header field of a request
  */
-static inline int
+int
 get_from_tag(struct sip_msg* _m, str* _tag)
 {
 
@@ -488,7 +591,7 @@
  * (so make sure it is, before calling this function or
  *  it might fail even if the message _has_ a callid)
  */
-static inline int
+int
 get_callid(struct sip_msg* _m, str* _cid)
 {
 
@@ -562,9 +665,13 @@
    if (anchor == 0)
        return -1;
 
-   hostport = uri.host;
-   if (uri.port.len > 0)
-       hostport.len = uri.port.s + uri.port.len - uri.host.s;
+   if (uri.maddr_val.len == 0) {
+       hostport = uri.host;
+       if (uri.port.len > 0)
+           hostport.len = uri.port.s + uri.port.len - uri.host.s;
+   } else {
+       hostport = uri.maddr_val;
+   }
 
    cp = ip_addr2a(&msg->rcv.src_ip);
    len = c->uri.len + strlen(cp) + 6 /* :port */ - hostport.len + 1;
@@ -651,11 +758,22 @@
 {
    struct sip_uri uri;
    contact_t* c;
+   char t;
+   str host;
+   short int port;
 
    if (get_contact_uri(msg, &uri, &c) == -1)
        return -1;
 
-   return (is1918addr(&(uri.host)) == 1) ? 1 : 0;
+   if (uri.maddr_val.len == 0)
+       return (is1918addr(&(uri.host)) == 1) ? 1 : 0;
+   t = uri.maddr_val.s[uri.maddr_val.len];
+   uri.maddr_val.s[uri.maddr_val.len] = '\0';
+   parse_hostport(uri.maddr_val.s, &host, &port);
+   uri.maddr_val.s[uri.maddr_val.len] = t;
+   if (host.len <= 0)
+       return 0;
+   return (is1918addr(&host) == 1) ? 1 : 0;
 }
 
 /*
@@ -755,8 +873,8 @@
 static int
 fix_nated_sdp_f(struct sip_msg* msg, char* str1, char* str2)
 {
-   str body, body1, oldip, oldip1, newip;
-   int level, pf, pf1;
+   str body, body1, oldip, newip;
+   int level, pf;
    char *buf;
    struct lump* anchor;
 
@@ -803,37 +921,43 @@
    }
 
    if (level & FIX_MEDIP) {
-       if (extract_mediaip(&body, &oldip, &pf) == -1) {
-           LOG(L_ERR, "ERROR: fix_nated_sdp: can't extract media IP from the SDP\n");
-           goto finalize;
-       }
-       if (pf != AF_INET) {
-           LOG(L_ERR, "ERROR: fix_nated_sdp: "
-               "not an IPv4 address in SDP\n");
-           goto finalize;
-       }
-       body1.s = oldip.s + oldip.len;
-       body1.len = body.s + body.len - body1.s;
-       if (extract_mediaip(&body1, &oldip1, &pf1) == -1) {
-           oldip1.len = 0;
-       }
-       if (oldip1.len > 0 && pf != pf1) {
-           LOG(L_ERR, "ERROR: fix_nated_sdp: mismatching "
-               "address families in SDP\n");
-           return -1;
-       }
-
+       /* Iterate all c= and replace ips in them. */
+       unsigned hasreplaced = 0;
+       int pf1 = 0;
+       str body2;
+       char* bodylimit = body.s + body.len;
        newip.s = ip_addr2a(&msg->rcv.src_ip);
        newip.len = strlen(newip.s);
-       if (alter_mediaip(msg, &body, &oldip, pf, &newip, pf,
-           1) == -1) {
-           LOG(L_ERR, "ERROR: fix_nated_sdp: can't alter media IP");
-           return -1;
+       body1 = body;
+       for(;;) {
+           if (extract_mediaip(&body1, &oldip, &pf) == -1)
+               break;
+           if (pf != AF_INET) {
+               LOG(L_ERR, "ERROR: fix_nated_sdp: "
+                   "not an IPv4 address in SDP\n");
+               goto finalize;
+           }
+           if (!pf1)
+               pf1 = pf;
+           else if (pf != pf1) {
+               LOG(L_ERR, "ERROR: fix_nated_sdp: mismatching "
+                   "address families in SDP\n");
+               return -1;
+           }
+           body2.s = oldip.s + oldip.len;
+           body2.len = bodylimit - body2.s;
+           if (alter_mediaip(msg, &body1, &oldip, pf, &newip, pf,
+               1) == -1)
+           {
+               LOG(L_ERR, "ERROR: fix_nated_sdp: can't alter media IP");
+               return -1;
+           }
+           hasreplaced = 1;
+           body1 = body2;
        }
-       if (oldip1.len > 0 && alter_mediaip(msg, &body, &oldip1, pf1,
-           &newip, pf, 0) == -1) {
-           LOG(L_ERR, "ERROR: fix_nated_sdp: can't alter media IP");
-           return -1;
+       if (!hasreplaced) {
+           LOG(L_ERR, "ERROR: fix_nated_sdp: can't extract media IP from the SDP\n");
+           goto finalize;
        }
    }
 
@@ -841,7 +965,7 @@
    return 1;
 }
 
-static int
+int
 extract_mediaip(str *body, str *mediaip, int *pf)
 {
    char *cp, *cp1;
@@ -855,7 +979,7 @@
        cp = cp1 + 2;
    }
    if (cp1 == NULL) {
-       LOG(L_DBG, "ERROR: extract_mediaip: no `c=' in SDP\n");
+       LOG(L_ERR, "ERROR: extract_mediaip: no `c=' in SDP\n");
        return -1;
    }
    mediaip->s = cp1 + 2;
@@ -897,11 +1021,12 @@
    return 1;
 }
 
-static int
+int
 extract_mediaport(str *body, str *mediaport)
 {
    char *cp, *cp1;
-   int len;
+   int len, i;
+   str ptype;
 
    cp1 = NULL;
    for (cp = body->s; (len = body->s + body->len - cp) > 0;) {
@@ -914,32 +1039,62 @@
        LOG(L_ERR, "ERROR: extract_mediaport: no `m=' in SDP\n");
        return -1;
    }
-   mediaport->s = cp1 + 2;
+   mediaport->s = cp1 + 2; /* skip `m=' */
    mediaport->len = eat_line(mediaport->s, body->s + body->len -
      mediaport->s) - mediaport->s;
    trim_len(mediaport->len, mediaport->s, *mediaport);
 
-   if (mediaport->len > 6 && memcmp(mediaport->s, "audio", 5) == 0 &&
-       isspace((int)mediaport->s[5])) {
-       mediaport->s += 5;
-       mediaport->len -= 5;
-   } else if (mediaport->len > 12 && memcmp(mediaport->s, "application", 11) == 0 &&
-       isspace((int)mediaport->s[11])) {
-       mediaport->s += 11;
-       mediaport->len -= 11;
-   } else {
-       LOG(L_ERR, "ERROR: extract_mediaport: can't parse `m=' in SDP\n");
+   /* Skip media supertype and spaces after it */
+   cp = eat_token_end(mediaport->s, mediaport->s + mediaport->len);
+   mediaport->len -= cp - mediaport->s;
+   if (mediaport->len <= 0 || cp == mediaport->s) {
+       LOG(L_ERR, "ERROR: extract_mediaport: no port in `m='\n");
        return -1;
    }
+   mediaport->s = cp;
    cp = eat_space_end(mediaport->s, mediaport->s + mediaport->len);
-   mediaport->len = eat_token_end(cp, mediaport->s + mediaport->len) - cp;
+   mediaport->len -= cp - mediaport->s;
+   if (mediaport->len <= 0 || cp == mediaport->s) {
+       LOG(L_ERR, "ERROR: extract_mediaport: no port in `m='\n");
+       return -1;
+   }
+   /* Extract port */
    mediaport->s = cp;
-   return 1;
+   cp = eat_token_end(mediaport->s, mediaport->s + mediaport->len);
+   ptype.len = mediaport->len - (cp - mediaport->s);
+   if (ptype.len <= 0 || cp == mediaport->s) {
+       LOG(L_ERR, "ERROR: extract_mediaport: no port in `m='\n");
+       return -1;
+   }
+   ptype.s = cp;
+   mediaport->len = cp - mediaport->s;
+   /* Skip spaces after port */
+   cp = eat_space_end(ptype.s, ptype.s + ptype.len);
+   ptype.len -= cp - ptype.s;
+   if (ptype.len <= 0 || cp == ptype.s) {
+       LOG(L_ERR, "ERROR: extract_mediaport: no protocol type in `m='\n");
+       return -1;
+   }
+   /* Extract protocol type */
+   ptype.s = cp;
+   cp = eat_token_end(ptype.s, ptype.s + ptype.len);
+   if (cp == ptype.s) {
+       LOG(L_ERR, "ERROR: extract_mediaport: no protocol type in `m='\n");
+       return -1;
+   }
+   ptype.len = cp - ptype.s;
+
+   for (i = 0; sup_ptypes[i].s != NULL; i++)
+       if (ptype.len == sup_ptypes[i].len &&
+           strncasecmp(ptype.s, sup_ptypes[i].s, ptype.len) == 0)
+           return 0;
+   /* Unproxyable protocol type. Generally it isn't error. */
+   return -1;
 }
 
-static int
+int
 alter_mediaip(struct sip_msg *msg, str *body, str *oldip, int oldpf,
-  str *newip, int newpf, int preserve)
+  str *newip, int newpf, int flags)
 {
    char *buf;
    int offset;
@@ -947,7 +1102,7 @@
    str omip, nip, oip;
 
    /* check that updating mediaip is really necessary */
-   if (oldpf == newpf && isnulladdr(oldip, oldpf))
+   if (oldpf == newpf && isnulladdr(oldip, oldpf) && !(flags & 2))
        return 0;
    if (newip->len == oldip->len &&
        memcmp(newip->s, oldip->s, newip->len) == 0)
@@ -960,7 +1115,7 @@
     * another request comes.
     */
 #if 0
-   /* disabled: 
+   /* disabled:
     *  - alter_mediaip is called twice if 2 c= lines are present
     *    in the sdp (and we want to allow it)
     *  - the message flags are propagated in the on_reply_route
@@ -975,7 +1130,7 @@
    }
 #endif
 
-   if (preserve != 0) {
+   if ((flags & 1) != 0) {
        anchor = anchor_lump(msg, body->s + body->len - msg->buf, 0, 0);
        if (anchor == NULL) {
            LOG(L_ERR, "ERROR: alter_mediaip: anchor_lump failed\n");
@@ -1051,7 +1206,7 @@
    return 0;
 }
 
-static int
+int
 alter_mediaport(struct sip_msg *msg, str *body, str *oldport, str *newport,
   int preserve)
 {
@@ -1127,6 +1282,161 @@
    return 0;
 }
 
+/*
+ * Finds specified text in area [*pp...bodylimit) at line beginning.
+ * Returns pointer to text, updates *pp to position after it.
+ */
+
+static char*
+find_sdp_text_bol(char **pp, char *plimit, char *text, size_t textlen)
+{
+   /* Find text at beginning of line */
+   if (*pp == NULL)
+       return NULL;
+   for(;;) {
+       char* p;
+       if (*pp >= plimit)
+           return NULL;
+       if (!(p = ser_memmem(*pp, text, plimit - *pp, textlen))) {
+           *pp = plimit;
+           return NULL;
+       }
+       *pp = p + 1;
+       if (p[-1] != '\n' && p[-1] != '\r')
+           continue;
+       return p;
+   }
+   /*UNREACHED*/
+   return NULL;
+}
+
+static int
+fixate_sdp_f(struct sip_msg* msg, char* str1, char* str2)
+{
+   char *cp;
+   int newpf;
+   str body, newip, newport, dest, oldip, oldport;
+   struct sip_uri ruri;
+   struct hdr_field *hdr;
+   struct via_body *rvia;
+   char *bodylimit, *v1p, *v2p, *m1p, *m2p, *c1p, *c2p;
+   char *om_ip_pos, *om_port_pos;
+   int c1_altered;
+
+   if (msg->first_line.type == SIP_REQUEST &&
+       msg->first_line.u.request.method_value == METHOD_INVITE) {
+       LOG(L_ERR, "DEBUG: fixate_sdp: request\n");
+       if (msg->parsed_uri_ok) {
+           dest = msg->parsed_uri.host;
+       } else {
+           if (parse_uri(msg->new_uri.s, msg->new_uri.len, &ruri) < 0) {
+               LOG(L_ERR, "ERROR: fixate_sdp: can't parse request uri\n");
+               return -1;
+           }
+           dest = ruri.host;
+       }
+   } else if (msg->first_line.type == SIP_REPLY) {
+       LOG(L_ERR, "DEBUG: fixate_sdp: reply\n");
+       rvia = NULL;
+       for (hdr=msg->headers; hdr; hdr=hdr->next) {
+           if (hdr->type == HDR_VIA)
+               rvia = hdr->parsed;
+       }
+       if (rvia == NULL) {
+           LOG(L_ERR, "ERROR: fixate_sdp: no or incorrect Via in reply\n");
+           return -1;
+       }
+       if (rvia->received != NULL) {
+           dest = rvia->received->value;
+       } else {
+           dest = rvia->host;
+       }
+   } else {
+       return -1;
+   }
+
+   if (extract_body(msg, &body) == -1 || body.len == 0) {
+       LOG(L_ERR, "ERROR: fixate_sdp: can't extract body "
+           "from the message\n");
+       return -1;
+   }
+   bodylimit = body.s + body.len;
+   v2p = v1p = find_sdp_line(body.s, bodylimit, 'v');
+   if (!v1p) {
+       LOG(L_ERR, "fixate_sdp: no sessions found\n");
+       return -1;
+   }
+   om_ip_pos = body.s;
+   om_port_pos = body.s;
+   for(;;) {
+       v1p = v2p;
+       if (v1p == NULL || v1p >= bodylimit)
+           break;
+       v2p = find_next_sdp_line(v1p, bodylimit, 'v', bodylimit);
+       m2p = m1p = find_sdp_line(v1p, v2p, 'm');
+       c1p = find_sdp_line(v1p, v2p, 'c');
+       c1_altered = 0;
+       if (!m1p) {
+           LOG(L_ERR, "fixate_sdp: session without media\n");
+           return -1;
+       }
+       for(;;) {
+           str tmpstr1;
+           m1p = m2p;
+           if (m1p == NULL || m1p >= v2p)
+               break;
+           m2p = find_next_sdp_line(m1p, v2p, 'm', v2p);
+           c2p = find_sdp_line(m1p, m2p, 'c');
+           /* Set old port and IP. Order doesn't matter. */
+           tmpstr1.s = m1p;
+           tmpstr1.len = bodylimit - m1p;
+           if (extract_mediaport(&tmpstr1, &newport) == -1) {
+               LOG(L_ERR, "ERROR: fixate_sdp: can't extract media port from the SDP\n");
+               return -1;
+           }
+           cp = find_sdp_text_bol(&om_port_pos, bodylimit, AOLDMEDPRT, AOLDMEDPRT_LEN);
+           if (cp) {
+               oldport.s = cp + AOLDMEDPRT_LEN;
+               oldport.len = eat_line(oldport.s, bodylimit - oldport.s) - oldport.s;
+               trim_len(oldport.len, oldport.s, oldport);
+               if (oldport.len != 0 &&
+                   alter_mediaport(msg, &body, &newport, &oldport, 0) == -1)
+                   return -1;
+           }
+           if (c2p || !c1_altered) {
+               tmpstr1.s = c2p ? c2p : c1p;
+               tmpstr1.len = bodylimit - tmpstr1.s;
+               if (extract_mediaip(&tmpstr1, &newip, &newpf) == -1) {
+                   LOG(L_ERR, "ERROR: fixate_sdp: can't extract media IP from the SDP\n");
+                   return -1;
+               }
+               if (newip.len != dest.len || memcmp(newip.s, dest.s, dest.len) != 0 ||
+                   isnulladdr(&newip, newpf))
+                   return -1;
+               cp = find_sdp_text_bol(&om_ip_pos, bodylimit, AOLDMEDIP, AOLDMEDIP_LEN);
+               if (cp) {
+                   oldip.s = cp + AOLDMEDIP_LEN;
+                   oldip.len = eat_line(oldip.s, bodylimit - oldip.s) - oldip.s;
+                   trim_len(oldip.len, oldip.s, oldip);
+               }
+               if (newip.len == oldip.len &&
+                   memcmp(newip.s, oldip.s, newip.len) == 0)
+                   oldip.len = 0;
+                       
+               if (oldip.len != 0) {
+                   if (alter_mediaip(msg, &body, &newip, newpf, &oldip, AF_INET,
+                       0) == -1)
+                       return -1;
+               }
+               if (!c2p)
+                   c1_altered = 1;
+           } /* if rewrite IP */
+       } /* medias */
+   } /* sessions */
+
+   return 1;
+}
+
 static char *
 gencookie()
 {
@@ -1138,45 +1448,58 @@
 }
 
 static int
-rtpp_test(int isdisabled, int force)
+rtpp_test(struct rtpp_node *node, int isdisabled, int force)
 {
    int rtpp_ver;
-   static int recheck_ticks = 0;
    char *cp;
    struct iovec v[2] = {{NULL, 0}, {"V", 1}};
+   struct iovec vf[4] = {{NULL, 0}, {"VF", 2}, {" ", 1},
+       {REQ_CPROTOVER, 8}};
 
    if (force == 0) {
        if (isdisabled == 0)
            return 0;
-       if (recheck_ticks > get_ticks())
+       if (node->rn_recheck_ticks > get_ticks())
            return 1;
    }
-   cp = send_rtpp_command(v, 2);
-   if (cp == NULL) {
-       LOG(L_WARN,"WARNING: rtpp_test: can't get version of "
-           "the RTP proxy\n");
-   } else {
+   do {
+       cp = send_rtpp_command(node, v, 2);
+       if (cp == NULL) {
+           LOG(L_WARN,"WARNING: rtpp_test: can't get version of "
+               "the RTP proxy\n");
+           break;
+       }
        rtpp_ver = atoi(cp);
-       if (rtpp_ver == SUP_CPROTOVER) {
-           LOG(L_INFO, "rtpp_test: RTP proxy found, support for "
-               "it %senabled\n", force == 0 ? "re-" : "");
-           return 0;
+       if (rtpp_ver != SUP_CPROTOVER) {
+           LOG(L_WARN, "WARNING: rtpp_test: unsupported "
+               "version of RTP proxy <%s> found: %d supported, "
+               "%d present\n", node->rn_url,
+               SUP_CPROTOVER, rtpp_ver);
+           break;
        }
-       LOG(L_WARN, "WARNING: rtpp_test: unsupported "
-           "version of RTP proxy found: %d supported, "
-           "%d present\n", SUP_CPROTOVER, rtpp_ver);
-   }
-   LOG(L_WARN, "WARNING: rtpp_test: support for RTP proxy "
-       "has been disabled%s\n",
+       cp = send_rtpp_command(node, vf, 4);
+       if (cp[0] == 'E' || atoi(cp) != 1) {
+           LOG(L_WARN, "WARNING: rtpp_test: of RTP proxy <%s>"
+               "doesn't support required protocol version %s\n",
+               node->rn_url, REQ_CPROTOVER);
+           break;
+       }
+       LOG(L_INFO, "rtpp_test: RTP proxy <%s> found, support for "
+           "it %senabled\n",
+           node->rn_url, force == 0 ? "re-" : "");
+       return 0;
+   } while(0);
+   LOG(L_WARN, "WARNING: rtpp_test: support for RTP proxy <%s>"
+       "has been disabled%s\n", node->rn_url,
        rtpproxy_disable_tout < 0 ? "" : " temporarily");
    if (rtpproxy_disable_tout >= 0)
-       recheck_ticks = get_ticks() + rtpproxy_disable_tout;
+       node->rn_recheck_ticks = get_ticks() + rtpproxy_disable_tout;
 
    return 1;
 }
 
-static char *
-send_rtpp_command(struct iovec *v, int vcnt)
+char *
+send_rtpp_command(struct rtpp_node *node, struct iovec *v, int vcnt)
 {
    struct sockaddr_un addr;
    int fd, len, i;
@@ -1186,10 +1509,10 @@
 
    len = 0;
    cp = buf;
-   if (umode == 0) {
+   if (node->rn_umode == 0) {
        memset(&addr, 0, sizeof(addr));
        addr.sun_family = AF_LOCAL;
-       strncpy(addr.sun_path, rtpproxy_sock,
+       strncpy(addr.sun_path, node->rn_address,
            sizeof(addr.sun_path) - 1);
 #ifdef HAVE_SOCKADDR_SA_LEN
        addr.sun_len = strlen(addr.sun_path);
@@ -1198,12 +1521,12 @@
        fd = socket(AF_LOCAL, SOCK_STREAM, 0);
        if (fd < 0) {
            LOG(L_ERR, "ERROR: send_rtpp_command: can't create socket\n");
-           return NULL;
+           goto badproxy;
        }
        if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
            close(fd);
            LOG(L_ERR, "ERROR: send_rtpp_command: can't connect to RTP proxy\n");
-           return NULL;
+           goto badproxy;
        }
 
        do {
@@ -1212,7 +1535,7 @@
        if (len <= 0) {
            close(fd);
            LOG(L_ERR, "ERROR: send_rtpp_command: can't send command to a RTP proxy\n");
-           return NULL;
+           goto badproxy;
        }
        do {
            len = read(fd, buf, sizeof(buf) - 1);
@@ -1220,38 +1543,38 @@
        close(fd);
        if (len <= 0) {
            LOG(L_ERR, "ERROR: send_rtpp_command: can't read reply from a RTP proxy\n");
-           return NULL;
+           goto badproxy;
        }
    } else {
-       fds[0].fd = controlfd;
+       fds[0].fd = node->rn_fd;
        fds[0].events = POLLIN;
        fds[0].revents = 0;
        /* Drain input buffer */
        while ((poll(fds, 1, 0) == 1) &&
            ((fds[0].revents & POLLIN) != 0)) {
-           recv(controlfd, buf, sizeof(buf) - 1, 0);
+           recv(node->rn_fd, buf, sizeof(buf) - 1, 0);
            fds[0].revents = 0;
        }
        v[0].iov_base = gencookie();
        v[0].iov_len = strlen(v[0].iov_base);
        for (i = 0; i < rtpproxy_retr; i++) {
            do {
-               len = writev(controlfd, v, vcnt);
+               len = writev(node->rn_fd, v, vcnt);
            } while (len == -1 && (errno == EINTR || errno == ENOBUFS));
            if (len <= 0) {
                LOG(L_ERR, "ERROR: send_rtpp_command: "
                    "can't send command to a RTP proxy\n");
-               return NULL;
+               goto badproxy;
            }
            while ((poll(fds, 1, rtpproxy_tout * 1000) == 1) &&
                (fds[0].revents & POLLIN) != 0) {
                do {
-                   len = recv(controlfd, buf, sizeof(buf) - 1, 0);
+                   len = recv(node->rn_fd, buf, sizeof(buf) - 1, 0);
                } while (len == -1 && errno == EINTR);
                if (len <= 0) {
                    LOG(L_ERR, "ERROR: send_rtpp_command: "
                        "can't read reply from a RTP proxy\n");
-                   return NULL;
+                   goto badproxy;
                }
                if (len >= (v[0].iov_len - 1) &&
                    memcmp(buf, v[0].iov_base, (v[0].iov_len - 1)) == 0) {
@@ -1269,28 +1592,97 @@
        if (i == rtpproxy_retr) {
            LOG(L_ERR, "ERROR: send_rtpp_command: "
                "timeout waiting reply from a RTP proxy\n");
-           return NULL;
+           goto badproxy;
        }
    }
 
 out:
    cp[len] = '\0';
    return cp;
+badproxy:
+   LOG(L_ERR, "send_rtpp_command(): proxy <%s> does not responding, disable it\n", node->rn_url);
+   node->rn_disabled = 1;
+   node->rn_recheck_ticks = get_ticks() + rtpproxy_disable_tout;
+   return NULL;
+}
+
+/*
+ * Main balancing routine. This does not try to keep the same proxy for
+ * the call if some proxies were disabled or enabled; proxy death considered
+ * too rare. Otherwise we should implement "mature" HA clustering, which is
+ * too expensive here.
+ */
+struct rtpp_node *
+select_rtpp_node(str callid, int do_test)
+{
+   unsigned sum, sumcut, weight_sum;
+   struct rtpp_node* node;
+   int was_forced;
+
+   /* Most popular case: 1 proxy, nothing to calculate */
+   if (rtpp_node_count == 1) {
+       node = rtpp_list.rn_first;
+       return node->rn_disabled ? NULL : node;
+   }
+
+   /* XXX Use quick-and-dirty hashing algo */
+   for(sum = 0; callid.len > 0; callid.len--)
+       sum += callid.s[callid.len - 1];
+   sum &= 0xff;
+
+   was_forced = 0;
+retry:
+   weight_sum = 0;
+   for (node = rtpp_list.rn_first; node != NULL; node = node->rn_next) {
+       if (node->rn_disabled) {
+           /* Try to enable if it's time to try. */
+           if (node->rn_recheck_ticks <= get_ticks())
+               node->rn_disabled = rtpp_test(node, 1, 0);
+       }
+       if (!node->rn_disabled)
+           weight_sum += node->rn_weight;
+   }
+   if (weight_sum == 0) {
+       /* No proxies? Force all to be redetected, if not yet */
+       if (was_forced)
+           return NULL;
+       was_forced = 1;
+       for (node = rtpp_list.rn_first; node != NULL; node = node->rn_next) {
+           node->rn_disabled = rtpp_test(node, 1, 1);
+       }
+       goto retry;
+   }
+   sumcut = sum % weight_sum;
+   /*
+    * sumcut here lays from 0 to weight_sum-1.
+    * Scan proxy list and decrease until appropriate proxy is found.
+    */
+   for (node = rtpp_list.rn_first; node != NULL; node = node->rn_next) {
+       if (node->rn_disabled)
+           continue;
+       if (sumcut < node->rn_weight)
+           goto found;
+       sumcut -= node->rn_weight;
+   }
+   /* No node list */
+   return NULL;
+found:
+   if (do_test) {
+       node->rn_disabled = rtpp_test(node, node->rn_disabled, 0);
+       if (node->rn_disabled)
+           goto retry;
+   }
+   return node;
 }
 
 static int
 unforce_rtp_proxy_f(struct sip_msg* msg, char* str1, char* str2)
 {
    str callid, from_tag, to_tag;
+   struct rtpp_node *node;
    struct iovec v[1 + 4 + 3] = {{NULL, 0}, {"D", 1}, {" ", 1}, {NULL, 0}, {" ", 1}, {NULL, 0}, {" ", 1}, {NULL, 0}};
                        /* 1 */   /* 2 */   /* 3 */    /* 4 */   /* 5 */    /* 6 */   /* 1 */
 
-   rtpproxy_disable = rtpp_test(rtpproxy_disable, 0);
-   if (rtpproxy_disable != 0) {
-       LOG(L_ERR, "ERROR: unforce_rtp_proxy: support for RTP proxy "
-           "is disabled\n");
-       return -1;
-   }
    if (get_callid(msg, &callid) == -1 || callid.len == 0) {
        LOG(L_ERR, "ERROR: unforce_rtp_proxy: can't get Call-Id field\n");
        return -1;
@@ -1306,29 +1698,139 @@
    STR2IOVEC(callid, v[3]);
    STR2IOVEC(from_tag, v[5]);
    STR2IOVEC(to_tag, v[7]);
-   send_rtpp_command(v, (to_tag.len > 0) ? 8 : 6);
+   node = select_rtpp_node(callid, 1);
+   if (!node) {
+       LOG(L_ERR, "ERROR: unforce_rtp_proxy: no available proxies\n");
+       return -1;
+   }
+   send_rtpp_command(node, v, (to_tag.len > 0) ? 8 : 6);
+
+   return 1;
+}
+
+/*
+ * Auxiliary for some functions.
+ * Returns pointer to first character of found line, or NULL if no such line.
+ */
+
+char*
+find_sdp_line(char *p, char *plimit, char linechar)
+{
+   static char linehead[3] = "x=";
+   char *cp, *cp1;
+   linehead[0] = linechar;
+   /* Iterate thru body */
+   cp = p;
+   for (;;) {
+       if (cp >= plimit)
+           return NULL;
+       cp1 = ser_memmem(cp, linehead, plimit-cp, 2);
+       if (cp1 == NULL)
+           return NULL;
+       /*
+        * As it is body, we assume it has previous line and we can
+        * lookup previous character.
+        */
+       if (cp1[-1] == '\n' || cp1[-1] == '\r')
+           return cp1;
+       /*
+        * Having such data, but not at line beginning.
+        * Skip them and reiterate. ser_memmem() will find next
+        * occurence.
+        */
+       if (plimit - cp1 < 2)
+           return NULL;
+       cp = cp1 + 2;
+   }
+   /*UNREACHED*/
+   return NULL;
+}
+
+/* This function assumes p points to a line of requested type. */
+
+char*
+find_next_sdp_line(char *p, char *plimit, char linechar, char *defptr)
+{
+   char* t;
+   if (p >= plimit || plimit - p < 3)
+       return defptr;
+   t = find_sdp_line(p + 2, plimit, linechar);
+   return t ? t : defptr;
+}
 
+static int
+alter_line(struct sip_msg *msg, str *where, str *what)
+{
+   struct lump *anchor;
+   anchor = del_lump(msg, where->s - msg->buf, where->len, 0);
+   if (!anchor) {
+       LOG(L_ERR, "del_lump() failed\n");
+       return 0;
+   }
+   if (insert_new_lump_after(anchor, what->s, what->len, 0) == 0) {
+       LOG(L_ERR, "insert_new_lump_after() failed\n");
+       return 0;
+   }
    return 1;
 }
 
+/*
+ * The following macro is used in force_rtp_proxy2_f() and twice
+ * in start_moh() 
+ */
+
+#define PARSE_PROXY_REPLY \
+        do { \
+           argc = 0;   \
+           memset(argv, 0, sizeof(argv));  \
+           cpend=cp+strlen(cp);    \
+           next=eat_token_end(cp, cpend);  \
+           for (ap = argv; cp<cpend; cp=next+1, next=eat_token_end(cp, cpend)){    \
+               *next=0;    \
+               if (*cp != '\0') {  \
+                   *ap=cp; \
+                   argc++; \
+                   if ((char*)++ap >= ((char*)argv+sizeof(argv)))  \
+                       break;  \
+               }   \
+           } \
+       } while(0)
+
 static int
 force_rtp_proxy2_f(struct sip_msg* msg, char* str1, char* str2)
 {
-   str body, body1, oldport, oldip, oldip1, newport, newip;
-   str callid, from_tag, to_tag, tmp;
+   str body, body1, oldport, oldip, newport, newip;
+   str callid, from_tag, to_tag;
    int create, port, len, asymmetric, flookup, argc, proxied, real;
+   int create1;
    int oidx, pf, pf1, force;
    char opts[16];
    char *cp, *cp1;
    char  *cpend, *next;
    char **ap, *argv[10];
    struct lump* anchor;
-   struct iovec v[1 + 6 + 5] = {{NULL, 0}, {NULL, 0}, {" ", 1}, {NULL, 0},
-       {" ", 1}, {NULL, 7}, {" ", 1}, {NULL, 1}, {" ", 1}, {NULL, 0},
-       {" ", 1}, {NULL, 0}};
-                       /* 1 */    /* 2 */   /* 3 */    /* 4 */
-       /* 5 */    /* 6 */   /* 7 */    /* 8 */   /* 9 */    /* 10 */
-       /* 11 */
+   struct rtpp_node *node;
+   struct iovec v[14] = {
+       {NULL, 0},  /* command */
+       {NULL, 0},  /* options */
+       {" ", 1},   /* separator */
+       {NULL, 0},  /* callid */
+       {" ", 1},   /* separator */
+       {NULL, 7},  /* newip */
+       {" ", 1},   /* separator */
+       {NULL, 1},  /* oldport */
+       {" ", 1},   /* separator */
+       {NULL, 0},  /* from_tag */
+       {";", 1},   /* separator */
+       {NULL, 0},  /* medianum */
+       {" ", 1},   /* separator */
+       {NULL, 0}   /* to_tag */
+   };
+   char *v1p, *v2p, *c1p, *c2p, *m1p, *m2p, *bodylimit;
+   char medianum_buf[20];
+   int medianum, media_multi;
+   str medianum_str, tmpstr1;
+   int c1_altered;
 
    v[1].iov_base=opts;
    asymmetric = flookup = force = real = 0;
@@ -1373,13 +1875,6 @@
        }
    }
 
-   rtpproxy_disable = rtpp_test(rtpproxy_disable, 0);
-   if (rtpproxy_disable != 0) {
-       LOG(L_ERR, "ERROR: force_rtp_proxy2: support for RTP proxy "
-           "is disabled\n");
-       return -1;
-   }
-
    if (msg->first_line.type == SIP_REQUEST &&
        msg->first_line.u.request.method_value == METHOD_INVITE) {
        create = 1;
@@ -1408,14 +1903,7 @@
        LOG(L_ERR, "ERROR: force_rtp_proxy2: can't get From tag\n");
        return -1;
    }
-   if (flookup != 0) {
-       if (create == 0 || to_tag.len == 0)
-           return -1;
-       create = 0;
-       tmp = from_tag;
-       from_tag = to_tag;
-       to_tag = tmp;
-   }
+
    proxied = 0;
    for (cp = body.s; (len = body.s + body.len - cp) >= ANORTPPROXY_LEN;) {
        cp1 = ser_memmem(cp, ANORTPPROXY, len, ANORTPPROXY_LEN);
@@ -1429,88 +1917,198 @@
    }
    if (proxied != 0 && force == 0)
        return -1;
-   if (extract_mediaip(&body, &oldip, &pf) == -1) {
-       LOG(L_ERR, "ERROR: force_rtp_proxy2: can't extract media IP "
-           "from the message\n");
-       return -1;
-   }
-   if (asymmetric != 0 || real != 0) {
-       newip = oldip;
-   } else {
-       newip.s = ip_addr2a(&msg->rcv.src_ip);
-       newip.len = strlen(newip.s);
-   }
-   body1.s = oldip.s + oldip.len;
-   body1.len = body.s + body.len - body1.s;
-   if (extract_mediaip(&body1, &oldip1, &pf1) == -1) {
-       oldip1.len = 0;
-   }
-   if (oldip1.len > 0 && pf != pf1) {
-       LOG(L_ERR, "ERROR: force_rtp_proxy2: mismatching address "
-           "families in SDP\n");
-       return -1;
-   }
-   if (extract_mediaport(&body, &oldport) == -1) {
-       LOG(L_ERR, "ERROR: force_rtp_proxy2: can't extract media port "
-           "from the message\n");
+   /*
+    * Parsing of SDP body.
+    * It can contain a few session descriptions (each start with
+    * "v=" line), and each session may contain a few media descriptions
+    * (each start with "m=" line).
+    * We have to change ports in "m=", and also change IP addresses in
+    * "c=" which can be placed either in session header (fallback for
+    * all medias) or media description.
+    * Ports should be allocated for any media. IPs all should be changed
+    * to the same value (RTP proxy IP), so we can change all "c="
+    * unconditionally.
+    */
+   bodylimit = body.s + body.len;
+   v1p = find_sdp_line(body.s, bodylimit, 'v');
+   if (v1p == NULL) {
+       LOG(L_ERR, "ERROR: force_rtp_proxy2: no sessions in SDP\n");
        return -1;
    }
-   if (pf == AF_INET6) {
-       opts[oidx] = '6';
-       oidx++;
-   }
-   opts[0] = (create == 0) ? 'L' : 'U';
-   v[1].iov_len = oidx;
-   STR2IOVEC(callid, v[3]);
-   STR2IOVEC(newip, v[5]);
-   STR2IOVEC(oldport, v[7]);
-   STR2IOVEC(from_tag, v[9]);
-   STR2IOVEC(to_tag, v[11]);
-   cp = send_rtpp_command(v, (to_tag.len > 0) ? 12 : 10);
-   if (cp == NULL)
-       return -1;
-   argc = 0;
-   memset(argv, 0, sizeof(argv));
-   cpend=cp+strlen(cp);
-   next=eat_token_end(cp, cpend);
-   for (ap = argv; cp<cpend; cp=next+1, next=eat_token_end(cp, cpend)){
-       *next=0;
-       if (*cp != '\0') {
-           *ap=cp;
-           argc++;
-           if ((char*)++ap >= ((char*)argv+sizeof(argv)))
-               break;
+   v2p = find_next_sdp_line(v1p, bodylimit, 'v', bodylimit);
+   media_multi = (v2p != bodylimit);
+   v2p = v1p;
+   medianum = 0;
+   for (;;) {
+       unsigned nmseen, nmchanged;
+       /* Per-session iteration. */
+       v1p = v2p;
+       if (v1p == NULL || v1p >= bodylimit)
+           break; /* No sessions left */
+       v2p = find_next_sdp_line(v1p, bodylimit, 'v', bodylimit);
+       /* v2p is text limit for session parsing. */
+       m1p = find_sdp_line(v1p, v2p, 'm');
+       /* Have this session media description? */
+       if (m1p == NULL) {
+           LOG(L_ERR, "ERROR: force_rtp_proxy2: no m= in session\n");
+           return -1;
        }
-   }
-   if (argc < 1)
-       return -1;
-   port = atoi(argv[0]);
-   if (port <= 0 || port > 65535)
-       return -1;
+       /*
+        * Find c1p only between session begin and first media.
+        * c1p will give common c= for all medias.
+        */
+       c1p = find_sdp_line(v1p, m1p, 'c');
+       c1_altered = 0;
+       /* Have session. Iterate media descriptions in session */
+       m2p = m1p;
+       nmseen = nmchanged = 0;
+       for (;;) {
+           create1 = create;
+           if (flookup != 0) {
+               if (!create || to_tag.len <= 0) {
+                   LOG(L_ERR, "force_rtp_proxy(): inappropriate 'l'\n");
+                   return -1;
+               }
+               create1 = 0;
+           }
+           m1p = m2p;
+           if (m1p == NULL || m1p >= v2p)
+               break;
+           m2p = find_next_sdp_line(m1p, v2p, 'm', v2p);
+           /* c2p will point to per-media "c=" */
+           c2p = find_sdp_line(m1p, m2p, 'c');
+           /* Extract address and port */
+           tmpstr1.s = c2p ? c2p : c1p;
+           ++nmseen;
+           if (tmpstr1.s == NULL) {
+               /* No "c=" */
+               LOG(L_ERR, "ERROR: force_rtp_proxy2: can't find media IP "
+                   "in the message\n");
+               return -1;
+           }
+           tmpstr1.len = v2p - tmpstr1.s; /* limit is session limit text */
+           if (extract_mediaip(&tmpstr1, &oldip, &pf) == -1) {
+               LOG(L_ERR, "ERROR: force_rtp_proxy2: can't extract media IP "
+                   "from the message\n");
+               return -1;
+           }
+           tmpstr1.s = m1p;
+           tmpstr1.len = m2p - m1p;
+           if (extract_mediaport(&tmpstr1, &oldport) == -1) {
+               LOG(L_ERR, "ERROR: force_rtp_proxy2: can't extract media port "
+                   "from the message\n");
+               return -1;
+           }
+           ++medianum;
+           if (asymmetric != 0 || real != 0) {
+               newip = oldip;
+           } else {
+               newip.s = ip_addr2a(&msg->rcv.src_ip);
+               newip.len = strlen(newip.s);
+           }
+           /* XXX must compare address families in all addresses */
+           if (pf == AF_INET6) {
+               opts[oidx] = '6';
+               oidx++;
+           }
+           snprintf(medianum_buf, sizeof medianum_buf, "%d", medianum);
+           medianum_str.s = medianum_buf;
+           medianum_str.len = strlen(medianum_buf);
+           opts[0] = (create1 == 0) ? 'L' : 'U';
+           v[1].iov_len = oidx;
+           STR2IOVEC(callid, v[3]);
+           STR2IOVEC(newip, v[5]);
+           STR2IOVEC(oldport, v[7]);
+           /*assert(!flookup || to_tag.len > 0);*/
+           STR2IOVEC(flookup ? to_tag : from_tag, v[9]);
+           if (1 || media_multi) /* XXX */ {
+               STR2IOVEC(medianum_str, v[11]);
+           } else {
+               v[10].iov_len = v[11].iov_len = 0;
+           }
+           STR2IOVEC(flookup ? from_tag : to_tag, v[13]);
+           do {
+               node = select_rtpp_node(callid, 1);
+               if (!node) {
+                   LOG(L_ERR, "ERROR: force_rtp_proxy2: no available proxies\n");
+                   return -1;
+               }
+               cp = send_rtpp_command(node, v,
+                   (to_tag.len > 0) ? 14 : 12);
+           } while (cp == NULL);
+           LOG(L_DBG, "force_rtp_proxy2: proxy reply: %s\n", cp);
+           PARSE_PROXY_REPLY;
+           if (argc < 1) {
+               LOG(L_ERR, "force_rtp_proxy2: no reply from rtp proxy\n");
+               return -1;
+           }
+           port = atoi(argv[0]);
+           if (port <= 0 || port > 65535) {
+               LOG(L_ERR, "force_rtp_proxy2: incorrect port in reply from rtp proxy\n");
+               return -1;
+           }
 
-   pf1 = (argc >= 3 && argv[2][0] == '6') ? AF_INET6 : AF_INET;
+           pf1 = (argc >= 3 && argv[2][0] == '6') ? AF_INET6 : AF_INET;
 
-   if (isnulladdr(&oldip, pf)) {
-       if (pf1 == AF_INET6) {
-           newip.s = "::";
-           newip.len = 2;
-       } else {
-           newip.s = "0.0.0.0";
-           newip.len = 7;
+           if (isnulladdr(&oldip, pf)) {
+               if (pf1 == AF_INET6) {
+                   newip.s = "::";
+                   newip.len = 2;
+               } else {
+                   newip.s = "0.0.0.0";
+                   newip.len = 7;
+               }
+           } else {
+               newip.s = (argc < 2) ? str2 : argv[1];
+               newip.len = strlen(newip.s);
+           }
+           newport.s = int2str(port, &newport.len); /* beware static buffer */
+           /* Alter port. */
+           body1.s = m1p;
+           body1.len = bodylimit - body1.s;
+           if (alter_mediaport(msg, &body1, &oldport, &newport, 0) == -1)
+               return -1;
+           /*
+            * Alter IP. Don't alter IP common for the session
+            * more than once.
+            */
+           if (c2p != NULL || !c1_altered) {
+               body1.s = c2p ? c2p : c1p;
+               body1.len = bodylimit - body1.s;
+               if (alter_mediaip(msg, &body1, &oldip, pf, &newip, pf1, 0) == -1)
+                   return -1;
+               if (!c2p)
+                   c1_altered = 1;
+           }
+           ++nmchanged;
+           /*
+            * Gross hack: turn off flookup here, after first
+            * media stream. This is used to allow changing number
+            * of media streams during re-INVITE.
+            */
+           flookup = 0;
+       } /* Iterate medias in session */
+       if (c1p && nmseen == nmchanged && !c1_altered) {
+           /* Alter default c-line of this session. */
+           str c1s, janus;
+           size_t newlen;
+           c1s.s = c1p;
+           c1s.len = eat_line(c1p, bodylimit - c1p) - c1p;
+           newlen = c1s.len + 6 + 1;
+           janus.s = pkg_malloc(c1s.len);
+           if (janus.s == NULL) {
+               LOG(L_ERR, "pkg_malloc failed\n");
+               return 0;
+           }
+           sprintf(janus.s, "a=oldc:%*.*s",
+               (int) c1s.len, (int) c1s.len, c1s.s);
+           janus.len = strlen(janus.s);
+           if (alter_line(msg, &c1s, &janus) <= 0) {
+               LOG(L_ERR, "alter_line() failed\n");
+               return 0;
+           }
        }
-   } else {
-       newip.s = (argc < 2) ? str2 : argv[1];
-       newip.len = strlen(newip.s);
-   }
-   newport.s = int2str(port, &newport.len); /* beware static buffer */
-
-   if (alter_mediaip(msg, &body, &oldip, pf, &newip, pf1, 0) == -1)
-       return -1;
-   if (oldip1.len > 0 &&
-       alter_mediaip(msg, &body1, &oldip1, pf, &newip, pf1, 0) == -1)
-       return -1;
-   if (alter_mediaport(msg, &body, &oldport, &newport, 0) == -1)
-       return -1;
+   } /* Iterate sessions */
 
    if (proxied == 0) {
        cp = pkg_malloc(ANORTPPROXY_LEN * sizeof(char));
@@ -1554,75 +2152,41 @@
    return force_rtp_proxy1_f(msg, arg, NULL);
 }
 
-static void
-timer(unsigned int ticks, void *param)
+static int
+rewrite_from_from_f(struct sip_msg* msg, char* str1, char* str2)
 {
-   int rval;
-   void *buf, *cp;
-   str c;
-   struct sip_uri curi;
-   union sockaddr_union to;
-   struct hostent* he;
-   struct socket_info* send_sock;
+   struct action act;
+   struct sip_uri uri;
+   str ruri;
 
-   buf = NULL;
-   if (cblen > 0) {
-       buf = pkg_malloc(cblen);
-       if (buf == NULL) {
-           LOG(L_ERR, "ERROR: nathelper::timer: out of memory\n");
-           return;
-       }
+   /* parsing from header */
+   if (parse_from_header(msg) == -1) {
+       LOG(L_ERR, "rewrite_from_from(): cannot get FROM header\n");
+       return -1;
    }
-   rval = ul.get_all_ucontacts(buf, cblen, (ping_nated_only ? FL_NAT : 0));
-   if (rval > 0) {
-       if (buf != NULL)
-           pkg_free(buf);
-       cblen = rval * 2;
-       buf = pkg_malloc(cblen);
-       if (buf == NULL) {
-           LOG(L_ERR, "ERROR: nathelper::timer: out of memory\n");
-           return;
-       }
-       rval = ul.get_all_ucontacts(buf, cblen, (ping_nated_only ? FL_NAT : 0));
-       if (rval != 0) {
-           pkg_free(buf);
-           return;
-       }
+   ruri.len = get_from(msg)->uri.len;
+   ruri.s = pkg_malloc(ruri.len + 1);
+   memcpy(ruri.s, get_from(msg)->uri.s, ruri.len + 1);
+   if (parse_uri(ruri.s, ruri.len, &uri) < 0) {
+       LOG(L_ERR, "rewrite_from_from(): can't parse FROM URI\n");
+       pkg_free(ruri.s);
+       return -1;
+   }
+   if (uri.user.len <= 0) {
+       uri.user.s = "Unknown";
+       uri.user.len = 7;
+   } else {
+       uri.user.s[uri.user.len] = '\0';
    }
 
-   if (buf == NULL)
-       return;
+   bzero(&act, sizeof(act));
+   act.type = SET_USER_T;
+   act.p1_type = STRING_ST;
+   act.p1.string = uri.user.s;
+   do_action(&act, msg);
 
-   cp = buf;
-   while (1) {
-       memcpy(&(c.len), cp, sizeof(c.len));
-       if (c.len == 0)
-           break;
-       c.s = (char*)cp + sizeof(c.len);
-       cp =  (char*)cp + sizeof(c.len) + c.len;
-       if (parse_uri(c.s, c.len, &curi) < 0) {
-           LOG(L_ERR, "ERROR: nathelper::timer: can't parse contact uri\n");
-           continue;
-       }
-       if (curi.proto != PROTO_UDP && curi.proto != PROTO_NONE)
-           continue;
-       if (curi.port_no == 0)
-           curi.port_no = SIP_PORT;
-       he = sip_resolvehost(&curi.host, &curi.port_no, PROTO_UDP);
-       if (he == NULL){
-           LOG(L_ERR, "ERROR: nathelper::timer: can't resolve_hos\n");
-           continue;
-       }
-       hostent2su(&to, he, 0, curi.port_no);
-       send_sock=force_socket ? force_socket : 
-                   get_send_socket(0, &to, PROTO_UDP);
-       if (send_sock == NULL) {
-           LOG(L_ERR, "ERROR: nathelper::timer: can't get sending socket\n");
-           continue;
-       }
-       udp_send(send_sock, (char *)sbuf, sizeof(sbuf), &to);
-   }
-   pkg_free(buf);
+   pkg_free(ruri.s);
+   return 1;
 }