/*****************************************************************************\ ** ** ** Linux Call Router ** ** ** **---------------------------------------------------------------------------** ** Copyright: Andreas Eversberg ** ** ** ** mISDN channel handlin for remote application ** ** ** \*****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #ifdef SOCKET_MISDN #include #include #include #include #include #else #include "mISDNlib.h" #include #endif #include "bchannel.h" #ifndef ISDN_PID_L4_B_USER #define ISDN_PID_L4_B_USER 0x440000ff #endif #define PERROR(arg...) fprintf(stderr, ##arg) #define PDEBUG(arg...) while(0) pid_t bchannel_pid; enum { BSTATE_IDLE, BSTATE_ACTIVATING, BSTATE_ACTIVE, }; #ifdef SOCKET_MISDN int bchannel_socket = -1; int bchannel_initialize(void) { /* try to open raw socket to check kernel */ bchannel_socket = socket(PF_ISDN, SOCK_RAW, ISDN_P_BASE); if (bchannel_socket < 0) { PERROR("Cannot open mISDN due to %s. (Does your Kernel support socket based mISDN?)\n", strerror(errno)); return(-1); } mISDN_debug_init(global_debug, NULL, NULL, NULL); bchannel_pid = get_pid(); /* init mlayer3 */ init_layer3(4); // buffer of 4 return(0); } void bchannel_deinitialize(void) { cleanup_layer3(); mISDN_debug_close(); if (bchannel_socket > -1) close(bchannel_socket); } #else int bchannel_entity = 0; /* used for udevice */ int bchannel_device = -1; /* the device handler and port list */ int bchannel_initialize(void) { char debug_log[128]; unsigned char buff[1025]; iframe_t *frm = (iframe_t *)buff; int ret; /* open mISDNdevice if not already open */ if (bchannel_device < 0) { ret = mISDN_open(); if (ret < 0) { PERROR("cannot open mISDN device ret=%d errno=%d (%s) Check for mISDN modules!\nAlso did you create \"/dev/mISDN\"? Do: \"mknod /dev/mISDN c 46 0\"\n", ret, errno, strerror(errno)); return(-1); } bchannel_device = ret; PDEBUG("mISDN device opened.\n"); /* create entity for layer 3 TE-mode */ mISDN_write_frame(bchannel_device, buff, 0, MGR_NEWENTITY | REQUEST, 0, 0, NULL, TIMEOUT_1SEC); ret = mISDN_read_frame(bchannel_device, frm, sizeof(iframe_t), 0, MGR_NEWENTITY | CONFIRM, TIMEOUT_1SEC); if (ret < (int)mISDN_HEADER_LEN) { noentity: PERROR("Cannot request MGR_NEWENTITY from mISDN. Exitting due to software bug."); return(-1); } bchannel_entity = frm->dinfo & 0xffff; if (!bchannel_entity) goto noentity; } return(0); } void bchannel_deinitialize(void) { unsigned char buff[1025]; if (bchannel_device >= 0) { /* free entity */ mISDN_write_frame(bchannel_device, buff, 0, MGR_DELENTITY | REQUEST, bchannel_entity, 0, NULL, TIMEOUT_1SEC); /* close device */ mISDN_close(bchannel_device); bchannel_device = -1; } } #endif /* * send control information to the channel (dsp-module) */ static void ph_control(unsigned long handle, unsigned long c1, unsigned long c2, char *trace_name, int trace_value) { #ifdef SOCKET_MISDN unsigned char buffer[MISDN_HEADER_LEN+sizeof(int)+sizeof(int)]; struct mISDNhead *ctrl = (struct mISDNhead *)buffer; unsigned long *d = buffer+MISDN_HEADER_LEN; int ret; ctrl->prim = PH_CONTROL_REQ; ctrl->id = 0; *d++ = c1; *d++ = c2; ret = sendto(handle, buffer, MISDN_HEADER_LEN+sizeof(int)*2, 0, NULL, 0); if (!ret) PERROR("Failed to send to socket %d\n", handle); #else unsigned char buffer[mISDN_HEADER_LEN+sizeof(int)+sizeof(int)]; iframe_t *ctrl = (iframe_t *)buffer; unsigned long *d = (unsigned long *)&ctrl->data.p; ctrl->prim = PH_CONTROL | REQUEST; ctrl->addr = handle | FLG_MSG_DOWN; ctrl->dinfo = 0; ctrl->len = sizeof(int)*2; *d++ = c1; *d++ = c2; mISDN_write(bchannel_device, ctrl, mISDN_HEADER_LEN+ctrl->len, TIMEOUT_1SEC); #endif #if 0 chan_trace_header(mISDNport, isdnport, "BCHANNEL control", DIRECTION_OUT); if (c1 == CMX_CONF_JOIN) add_trace(trace_name, NULL, "0x%08x", trace_value); else add_trace(trace_name, NULL, "%d", trace_value); end_trace(); #endif } static void ph_control_block(unsigned long handle, unsigned long c1, void *c2, int c2_len, char *trace_name, int trace_value) { #ifdef SOCKET_MISDN unsigned char buffer[MISDN_HEADER_LEN+sizeof(int)+c2_len]; struct mISDNhead *ctrl = (struct mISDNhead *)buffer; unsigned long *d = buffer+MISDN_HEADER_LEN; int ret; ctrl->prim = PH_CONTROL_REQ; ctrl->id = 0; *d++ = c1; memcpy(d, c2, c2_len); ret = sendto(handle, buffer, MISDN_HEADER_LEN+sizeof(int)+c2_len, 0, NULL, 0); if (!ret) PERROR("Failed to send to socket %d\n", handle); #else unsigned char buffer[mISDN_HEADER_LEN+sizeof(int)+c2_len]; iframe_t *ctrl = (iframe_t *)buffer; unsigned long *d = (unsigned long *)&ctrl->data.p; ctrl->prim = PH_CONTROL | REQUEST; ctrl->addr = handle | FLG_MSG_DOWN; ctrl->dinfo = 0; ctrl->len = sizeof(int)+c2_len; *d++ = c1; memcpy(d, c2, c2_len); mISDN_write(bchannel_device, ctrl, mISDN_HEADER_LEN+ctrl->len, TIMEOUT_1SEC); #endif #if 0 chan_trace_header(mISDNport, isdnport, "BCHANNEL control", DIRECTION_OUT); add_trace(trace_name, NULL, "%d", trace_value); end_trace(); #endif } /* * create stack */ int bchannel_create(struct bchannel *channel) { unsigned char buff[1024]; int ret; #ifdef SOCKET_MISDN unsigned long on = 1; struct sockadd_mISDN addr; if (channel->b_sock) { PERROR("Error: Socket already created for handle 0x%x\n", channel->handle); return(0); } /* open socket */ channel->b_sock = socket(PF_ISDN, SOCK_DGRAM, ISDN_P_B_L2DSP); if (channel->b_sock < 0) { PERROR("Error: Failed to open bchannel-socket for handle 0x%x with mISDN-DSP layer. Did you load mISDNdsp.ko?\n", channel->handle); return(0); } /* set nonblocking io */ ret = ioctl(channel->b_sock, FIONBIO, &on); if (ret < 0) { PERROR("Error: Failed to set bchannel-socket handle 0x%x into nonblocking IO\n", channel->handle); close(channel->b_sock); channel->b_sock = -1; return(0); } /* bind socket to bchannel */ addr.family = AF_ISDN; addr.dev = (channel->handle>>8)-1; addr.channel = channel->handle && 0xff; ret = bind(channel->b_sock, (struct sockaddr *)&addr, sizeof(addr)); if (ret < 0) { PERROR("Error: Failed to bind bchannel-socket for handle 0x%x with mISDN-DSP layer. Did you load mISDNdsp.ko?\n", channel->handle); close(channel->b_sock); channel->b_sock = -1; return(0); } #if 0 chan_trace_header(mISDNport, mISDNport->b_port[i], "BCHANNEL create socket", DIRECTION_OUT); add_trace("channel", NULL, "%d", i+1+(i>=15)); add_trace("socket", NULL, "%d", mISDNport->b_socket[i]); end_trace(); #endif #else layer_info_t li; mISDN_pid_t pid; if (channel->b_stid) { PERROR("Error: stack already created for address 0x%x\n", channel->b_stid); return(0); } if (channel->b_addr) { PERROR("Error: stack already created for address 0x%x\n", channel->b_addr); return(0); } /* create new layer */ PDEBUG("creating new layer for stid 0x%x.\n" , channel->handle); memset(&li, 0, sizeof(li)); memset(&pid, 0, sizeof(pid)); li.object_id = -1; li.extentions = 0; li.st = channel->handle; strcpy(li.name, "B L4"); li.pid.layermask = ISDN_LAYER((4)); li.pid.protocol[4] = ISDN_PID_L4_B_USER; ret = mISDN_new_layer(bchannel_device, &li); if (ret) { failed_new_layer: PERROR("mISDN_new_layer() failed to add bchannel for stid 0x%x.\n", channel->handle); goto failed; } if (!li.id) { goto failed_new_layer; } channel->b_stid = channel->handle; channel->b_addr = li.id; PDEBUG("new layer (b_addr=0x%x)\n", channel->b_addr); /* create new stack */ pid.protocol[1] = ISDN_PID_L1_B_64TRANS; pid.protocol[2] = ISDN_PID_L2_B_TRANS; pid.protocol[3] = ISDN_PID_L3_B_DSP; pid.protocol[4] = ISDN_PID_L4_B_USER; pid.layermask = ISDN_LAYER((1)) | ISDN_LAYER((2)) | ISDN_LAYER((3)) | ISDN_LAYER((4)); ret = mISDN_set_stack(bchannel_device, channel->b_stid, &pid); if (ret) { stack_error: PERROR("mISDN_set_stack() failed (ret=%d) to add bchannel stid=0x%x\n", ret, channel->b_stid); mISDN_write_frame(bchannel_device, buff, channel->b_addr, MGR_DELLAYER | REQUEST, 0, 0, NULL, TIMEOUT_1SEC); goto failed; } ret = mISDN_get_setstack_ind(bchannel_device, channel->b_addr); if (ret) goto stack_error; /* get layer id */ channel->b_addr = mISDN_get_layerid(bchannel_device, channel->b_stid, 4); if (!channel->b_addr) goto stack_error; #if 0 chan_trace_header(mISDNport, mISDNport->b_port[i], "BCHANNEL create stack", DIRECTION_OUT); add_trace("channel", NULL, "%d", i+1+(i>=15)); add_trace("stack", "id", "0x%08x", mISDNport->b_stid[i]); add_trace("stack", "address", "0x%08x", mISDNport->b_addr[i]); end_trace(); #endif #endif return(1); failed: channel->b_stid = 0; channel->b_addr = 0; return(0); } /* * activate / deactivate request */ void bchannel_activate(struct bchannel *channel, int activate) { #ifdef SOCKET_MISDN struct mISDNhead act; int ret; act.prim = (activate)?DL_ESTABLISH_REQ:DL_RELEASE_REQ; act.id = 0; ret = sendto(channel->b_sock, &act, MISDN_HEADER_LEN, 0, NULL, 0); if (!ret) PERROR("Failed to send to socket %d\n", channel->b_sock); #else iframe_t act; /* activate bchannel */ act.prim = (activate?DL_ESTABLISH:DL_RELEASE) | REQUEST; act.addr = channel->b_addr | FLG_MSG_DOWN; act.dinfo = 0; act.len = 0; mISDN_write(bchannel_device, &act, mISDN_HEADER_LEN+act.len, TIMEOUT_1SEC); #endif channel->b_state = BSTATE_ACTIVATING; #if 0 /* trace */ chan_trace_header(mISDNport, mISDNport->b_port[i], activate?(char*)"BCHANNEL activate":(char*)"BCHANNEL deactivate", DIRECTION_OUT); add_trace("channel", NULL, "%d", i+1+(i>=15)); end_trace(); #endif } /* * set features */ static void bchannel_activated(struct bchannel *channel) { #ifdef SOCKET_MISDN int handle; handle = channel->b_sock; #else unsigned long handle; handle = channel->b_addr; #endif /* set dsp features */ if (channel->b_txdata) ph_control(handle, (channel->b_txdata)?CMX_TXDATA_ON:CMX_TXDATA_OFF, 0, "DSP-TXDATA", channel->b_txdata); if (channel->b_delay) ph_control(handle, CMX_DELAY, channel->b_delay, "DSP-DELAY", channel->b_delay); if (channel->b_tx_dejitter) ph_control(handle, (channel->b_tx_dejitter)?CMX_TX_DEJITTER:CMX_TX_DEJ_OFF, 0, "DSP-DELAY", channel->b_tx_dejitter); if (channel->b_tx_gain) ph_control(handle, VOL_CHANGE_TX, channel->b_tx_gain, "DSP-TX_GAIN", channel->b_tx_gain); if (channel->b_rx_gain) ph_control(handle, VOL_CHANGE_RX, channel->b_rx_gain, "DSP-RX_GAIN", channel->b_rx_gain); if (channel->b_pipeline[0]) ph_control_block(handle, PIPELINE_CFG, channel->b_pipeline, strlen(channel->b_pipeline)+1, "DSP-PIPELINE", 0); if (channel->b_conf) ph_control(handle, CMX_CONF_JOIN, channel->b_conf, "DSP-CONF", channel->b_conf); if (channel->b_echo) ph_control(handle, CMX_ECHO_ON, 0, "DSP-ECHO", 1); if (channel->b_tone) ph_control(handle, TONE_PATT_ON, channel->b_tone, "DSP-TONE", channel->b_tone); if (channel->b_rxoff) ph_control(handle, CMX_RECEIVE_OFF, 0, "DSP-RXOFF", 1); // if (channel->b_txmix) // ph_control(handle, CMX_MIX_ON, 0, "DSP-MIX", 1); if (channel->b_dtmf) ph_control(handle, DTMF_TONE_START, 0, "DSP-DTMF", 1); if (channel->b_crypt_len) ph_control_block(handle, BF_ENABLE_KEY, channel->b_crypt_key, channel->b_crypt_len, "DSP-CRYPT", channel->b_crypt_len); if (channel->b_conf) ph_control(handle, CMX_CONF_JOIN, channel->b_conf, "DSP-CONF", channel->b_conf); channel->b_state = BSTATE_ACTIVE; } /* * destroy stack */ static void bchannel_destroy(struct bchannel *channel) { #ifdef SOCKET_MISDN #if 0 chan_trace_header(mISDNport, mISDNport->b_port[i], "BCHANNEL remove socket", DIRECTION_OUT); add_trace("channel", NULL, "%d", i+1+(i>=15)); add_trace("socket", NULL, "%d", mISDNport->b_socket[i]); end_trace(); #endif if (channel->b_sock > -1) { close(channel->b_sock); channel->b_sock = -1; } #else unsigned char buff[1024]; #if 0 chan_trace_header(mISDNport, mISDNport->b_port[i], "BCHANNEL remove stack", DIRECTION_OUT); add_trace("channel", NULL, "%d", i+1+(i>=15)); add_trace("stack", "id", "0x%08x", mISDNport->b_stid[i]); add_trace("stack", "address", "0x%08x", mISDNport->b_addr[i]); end_trace(); #endif /* remove our stack only if set */ if (channel->b_addr) { PDEBUG("free stack (b_addr=0x%x)\n", channel->b_addr); mISDN_clear_stack(bchannel_device, channel->b_stid); mISDN_write_frame(bchannel_device, buff, channel->b_addr | FLG_MSG_DOWN, MGR_DELLAYER | REQUEST, 0, 0, NULL, TIMEOUT_1SEC); channel->b_stid = 0; channel->b_addr = 0; } #endif channel->b_state = BSTATE_IDLE; } /* * whenever we get audio data from bchannel, we process it here */ static void bchannel_receive(struct bchannel *channel, unsigned long prim, unsigned long dinfo, unsigned char *data, int len) { unsigned long cont = *((unsigned long *)data); unsigned char *data_temp; unsigned long length_temp; unsigned char *p; int l; if (prim == (PH_CONTROL | INDICATION)) { if (len < 4) { PERROR("SHORT READ OF PH_CONTROL INDICATION\n"); return; } if ((cont&(~DTMF_TONE_MASK)) == DTMF_TONE_VAL) { #if 0 chan_trace_header(p_m_mISDNport, this, "BCHANNEL control", DIRECTION_IN); add_trace("DTMF", NULL, "%c", cont & DTMF_TONE_MASK); end_trace(); #endif if (channel->rx_dtmf) channel->rx_dtmf(channel, cont & DTMF_TONE_MASK); return; } switch(cont) { case BF_REJECT: #if 0 chan_trace_header(p_m_mISDNport, this, "BCHANNEL control", DIRECTION_IN); add_trace("DSP-CRYPT", NULL, "error"); end_trace(); #endif break; case BF_ACCEPT: #if 0 chan_trace_header(p_m_mISDNport, this, "BCHANNEL control", DIRECTION_IN); add_trace("DSP-CRYPT", NULL, "ok"); end_trace(); #endif break; default: #if 0 chan_trace_header(p_m_mISDNport, this, "BCHANNEL control", DIRECTION_IN); add_trace("unknown", NULL, "0x%x", cont); end_trace(); #else ; #endif } return; } if (prim == (PH_SIGNAL | INDICATION)) { switch(dinfo) { case CMX_TX_DATA: if (!channel->b_txdata) { /* if tx is off, it may happen that fifos send us pending informations, we just ignore them */ PDEBUG("PmISDN(%s) ignoring tx data, because 'txdata' is turned off\n", p_name); return; } break; default: #if 0 chan_trace_header(p_m_mISDNport, this, "BCHANNEL signal", DIRECTION_IN); add_trace("unknown", NULL, "0x%x", frm->dinfo); end_trace(); #else ; #endif } return; } if (prim != PH_DATA_IND && prim != DL_DATA_IND) { PERROR("Bchannel received unknown primitve: 0x%x\n", prim); return; } /* calls will not process any audio data unless * the call is connected OR interface features audio during call setup. */ /* if rx is off, it may happen that fifos send us pending informations, we just ignore them */ if (channel->b_rxoff) { PDEBUG("PmISDN(%s) ignoring data, because rx is turned off\n", p_name); return; } if (channel->rx_data) channel->rx_data(channel, data, len); } /* * transmit data to bchannel */ void bchannel_transmit(struct bchannel *channel, unsigned char *data, int len) { unsigned char buff[1025]; iframe_t *frm = (iframe_t *)buff; if (channel->b_state != BSTATE_ACTIVE) return; #ifdef SOCKET_MISDN frm->prim = DL_DATA_REQ; frm->id = 0; ret = sendto(channel->b_sock, data, len, 0, NULL, 0); if (!ret) PERROR("Failed to send to socket %d\n", channel->b_sock); #else frm->prim = DL_DATA | REQUEST; frm->addr = channel->b_addr | FLG_MSG_DOWN; frm->dinfo = 0; frm->len = len; if (frm->len) mISDN_write(bchannel_device, frm, mISDN_HEADER_LEN+frm->len, TIMEOUT_1SEC); #endif } /* * join bchannel */ void bchannel_join(struct bchannel *channel, unsigned short id) { #ifdef SOCKET_MISDN int handle; handle = channel->b_sock; #else unsigned long handle; handle = channel->b_addr; #endif if (id) channel->b_conf = (id<<16) + bchannel_pid; else channel->b_conf = 0; if (channel->b_state == BSTATE_ACTIVE) ph_control(handle, CMX_CONF_JOIN, channel->b_conf, "DSP-CONF", channel->b_conf); } /* * main loop for processing messages from mISDN */ #ifdef SOCKET_MISDN int bchannel_handle(void) { int ret, work = 0; struct bchannel *channel; int i; char buffer[2048+MISDN_HEADER_LEN]; struct mISDNhead *hh = (struct mISDNhead *)buffer; /* process all bchannels */ channel = bchannel_first; while(channel) { /* handle message from bchannel */ if (channel->b_sock > -1) { ret = recv(channel->b_sock, buffer, sizeof(buffer), 0); if (ret >= MISDN_HEADER_LEN) { work = 1; switch(hh->prim) { /* we don't care about confirms, we use rx data to sync tx */ case PH_DATA_CONF: case DL_DATA_CONF: break; /* we receive audio data, we respond to it AND we send tones */ case PH_DATA_IND: case DL_DATA_IND: case PH_SIGNAL_IND: case PH_CONTROL | INDICATION: bchannel_receive(channel, hh->prim, hh->dinfo, buffer+MISDN_HEADER_LEN, ret-MISDN_HEADER_LEN); break; case PH_ACTIVATE_IND: case DL_ESTABLISH_IND: case PH_ACTIVATE_CONF: case DL_ESTABLISH_CONF: PDEBUG("DL_ESTABLISH confirm: bchannel is now activated (socket %d).\n", channel->b_sock); bchannel_activated(channel); break; case PH_DEACTIVATE_IND: case DL_RELEASE_IND: case PH_DEACTIVATE_CONF: case DL_RELEASE_CONF: PDEBUG("DL_RELEASE confirm: bchannel is now de-activated (socket %d).\n", channel->b_sock); // bchannel_deactivated(channel); break; default: PERROR("child message not handled: prim(0x%x) socket(%d) msg->len(%d)\n", hh->prim, channel->b_sock, msg->len); } } else { if (ret < 0 && errno != EWOULDBLOCK) PERROR("Read from socket %d failed with return code %d\n", channel->b_sock, ret); } } channel = channel->next; } /* if we received at least one b-frame, we will return 1 */ return(work); } #else int bchannel_handle(void) { int i; struct bchannel *channel; iframe_t *frm; unsigned char buffer[2048]; struct mISDNhead *hh = (struct mISDNhead *)buffer; int len; /* no device, no read */ if (bchannel_device < 0) return(0); /* get message from kernel */ len = mISDN_read(bchannel_device, buffer, sizeof(buffer), 0); if (len < 0) { if (errno == EAGAIN) return(0); PERROR("Failed to do mISDN_read()\n"); return(0); } if (!len) { // printf("%s: ERROR: mISDN_read() returns nothing\n"); return(0); } frm = (iframe_t *)buffer; /* global prim */ switch(frm->prim) { case MGR_DELLAYER | CONFIRM: case MGR_INITTIMER | CONFIRM: case MGR_ADDTIMER | CONFIRM: case MGR_DELTIMER | CONFIRM: case MGR_REMOVETIMER | CONFIRM: return(1); } /* find the mISDNport that belongs to the stack */ channel = bchannel_first; while(channel) { if (frm->addr == channel->b_addr) break; channel = channel->next; } if (!channel) { PERROR("message belongs to no channel: prim(0x%x) addr(0x%x) msg->len(%d)\n", frm->prim, frm->addr, len); goto out; } /* b-message */ switch(frm->prim) { /* we don't care about confirms, we use rx data to sync tx */ case PH_DATA | CONFIRM: case DL_DATA | CONFIRM: break; /* we receive audio data, we respond to it AND we send tones */ case PH_DATA | INDICATION: case DL_DATA | INDICATION: case PH_CONTROL | INDICATION: case PH_SIGNAL | INDICATION: bchannel_receive(channel, frm->prim, frm->dinfo, (unsigned char *)frm->data.p, frm->len); break; case PH_ACTIVATE | INDICATION: case DL_ESTABLISH | INDICATION: case PH_ACTIVATE | CONFIRM: case DL_ESTABLISH | CONFIRM: PDEBUG( "DL_ESTABLISH confirm: bchannel is now activated (address 0x%x).\n", frm->addr); bchannel_activated(channel); break; case PH_DEACTIVATE | INDICATION: case DL_RELEASE | INDICATION: case PH_DEACTIVATE | CONFIRM: case DL_RELEASE | CONFIRM: PDEBUG("DL_RELEASE confirm: bchannel is now de-activated (address 0x%x).\n", frm->addr); // bchannel_deactivated(channel); break; default: PERROR("message not handled: prim(0x%x) addr(0x%x) msg->len(%d)\n", frm->prim, frm->addr, len); } out: return(1); } #endif /* * bchannel channel handling */ struct bchannel *bchannel_first = NULL; struct bchannel *find_bchannel_handle(unsigned long handle) { struct bchannel *channel = bchannel_first; while(channel) { if (channel->handle == handle) break; channel = channel->next; } return(channel); } struct bchannel *find_bchannel_ref(unsigned long ref) { struct bchannel *channel = bchannel_first; while(channel) { if (channel->ref == ref) break; channel = channel->next; } return(channel); } struct bchannel *alloc_bchannel(unsigned long handle) { struct bchannel **channelp = &bchannel_first; while(*channelp) channelp = &((*channelp)->next); *channelp = (struct bchannel *)malloc(sizeof(struct bchannel)); if (!*channelp) return(NULL); (*channelp)->handle = handle; (*channelp)->b_state = BSTATE_IDLE; return(*channelp); } void free_bchannel(struct bchannel *channel) { struct bchannel **temp = &bchannel_first; while(*temp) { if (*temp == channel) { *temp = (*temp)->next; #ifdef SOCKET_MISDN if (channel->b_sock > -1) #else if (channel->b_stid) #endif bchannel_destroy(channel); free(channel); return; } temp = &((*temp)->next); } }