/* * * PPP library with GLib integration * * Copyright (C) 2009-2010 Intel Corporation. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * */ #ifdef HAVE_CONFIG_H #include #endif #include #include #include #include #include #include #include #include #include #include "gatutil.h" #include "gatppp.h" #include "ppp.h" #define PPPINITFCS16 0xffff /* Initial FCS value */ #define PPPGOODFCS16 0xf0b8 /* Good final FCS value */ struct frame_buffer { gsize len; guint8 bytes[0]; }; static GList *packet_handlers = NULL; void ppp_register_packet_handler(struct ppp_packet_handler *handler) { packet_handlers = g_list_append(packet_handlers, handler); } /* * FCS lookup table copied from rfc1662. */ static guint16 fcstab[256] = { 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf, 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7, 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e, 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876, 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd, 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5, 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c, 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974, 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb, 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3, 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a, 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72, 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9, 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1, 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738, 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70, 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7, 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff, 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036, 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e, 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5, 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd, 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134, 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c, 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3, 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb, 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232, 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a, 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1, 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9, 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330, 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78 }; /* * Calculate a new fcs given the current fcs and the new data. * copied from rfc1662 * * The FCS field is calculated over all bits of the Address, Control, * Protocol, Information and Padding fields, not including any start * and stop bits (asynchronous) nor any bits (synchronous) or octets * (asynchronous or synchronous) inserted for transparency. This * also does not include the Flag Sequences nor the FCS field itself. */ static guint16 ppp_fcs(guint16 fcs, guint8 c) { guint16 new_fcs; new_fcs = (fcs >> 8) ^ fcstab[(fcs ^ c) & 0xff]; return new_fcs; } /* * escape any chars less than 0x20, and check the transmit accm table to * see if this character should be escaped. */ static gboolean ppp_escape(GAtPPP *ppp, guint8 c, gboolean lcp) { if ((lcp && c < 0x20) || (ppp->xmit_accm[c >> 5] & (1 << (c & 0x1f)))) return TRUE; return FALSE; } static void ppp_put(GAtPPP *ppp, guint8 *buf, int *pos, guint8 c, gboolean lcp) { int i = *pos; /* escape characters if needed, copy into buf, increment pos */ if (ppp_escape(ppp, c, lcp)) { buf[i++] = PPP_ESC; buf[i++] = c ^ 0x20; } else buf[i++] = c; *pos = i; } /* XXX implement PFC and ACFC */ static guint8 *ppp_encode(GAtPPP *ppp, guint8 *data, int len, guint *newlen) { int pos = 0; int i = 0; guint16 fcs = PPPINITFCS16; guint16 proto = get_host_short(data); gboolean lcp = (proto == LCP_PROTOCOL); guint8 *frame = g_try_malloc0(BUFFERSZ); if (!frame) return NULL; /* copy in the HDLC framing */ frame[pos++] = PPP_FLAG_SEQ; /* from here till end flag, calculate FCS over each character */ fcs = ppp_fcs(fcs, PPP_ADDR_FIELD); ppp_put(ppp, frame, &pos, PPP_ADDR_FIELD, lcp); fcs = ppp_fcs(fcs, PPP_CTRL); ppp_put(ppp, frame, &pos, PPP_CTRL, lcp); /* * for each byte, first calculate FCS, then do escaping if * neccessary */ while (len--) { fcs = ppp_fcs(fcs, data[i]); ppp_put(ppp, frame, &pos, data[i++], lcp); } /* add FCS */ fcs ^= 0xffff; /* complement */ ppp_put(ppp, frame, &pos, (guint8)(fcs & 0x00ff), lcp); ppp_put(ppp, frame, &pos, (guint8)((fcs >> 8) & 0x00ff), lcp); /* add flag */ frame[pos++] = PPP_FLAG_SEQ; *newlen = pos; return frame; } static gint is_proto_handler(gconstpointer a, gconstpointer b) { const struct ppp_packet_handler *h = a; const guint16 proto = (guint16) GPOINTER_TO_UINT(b); if (h->proto == proto) return 0; else return -1; } /* called when we have received a complete ppp frame */ static void ppp_recv(GAtPPP *ppp, struct frame_buffer *frame) { guint protocol = ppp_proto(frame->bytes); guint8 *packet = ppp_info(frame->bytes); struct ppp_packet_handler *h; GList *list; if (!frame) return; /* * check to see if we have a protocol handler * registered for this packet */ list = g_list_find_custom(packet_handlers, GUINT_TO_POINTER(protocol), is_proto_handler); if (list) { h = list->data; h->handler(h->priv, packet); } else lcp_protocol_reject(ppp->lcp, frame->bytes, frame->len); g_free(frame); } /* XXX - Implement PFC and ACFC */ static struct frame_buffer *ppp_decode(GAtPPP *ppp, guint8 *frame) { guint8 *data; guint pos; int i; guint16 fcs; struct frame_buffer *fb; fb = g_try_malloc0(sizeof(struct frame_buffer) + ppp->mru + 10); if (!fb) return NULL; data = fb->bytes; /* skip the first flag char */ pos = 1; fcs = PPPINITFCS16; i = 0; /* TBD - how to deal with recv_accm */ while (frame[pos] != PPP_FLAG_SEQ) { /* scan for escape character */ if (frame[pos] == PPP_ESC) { /* skip that char */ pos++; data[i] = frame[pos] ^ 0x20; } else data[i] = frame[pos]; fcs = ppp_fcs(fcs, data[i]); i++; pos++; } fb->len = i; /* see if we have a good FCS */ if (fcs != PPPGOODFCS16) { g_free(fb); return NULL; } return fb; } static void ppp_feed(GAtPPP *ppp, guint8 *data, gsize len) { guint pos = 0; struct frame_buffer *frame; /* collect bytes until we detect we have received a complete frame */ /* examine the data. If we are at the beginning of a new frame, * allocate memory to buffer the frame. */ for (pos = 0; pos < len; pos++) { if (data[pos] == PPP_FLAG_SEQ) { if (ppp->index != 0) { /* store last flag character & decode */ ppp->buffer[ppp->index++] = data[pos]; frame = ppp_decode(ppp, ppp->buffer); /* process receive frame */ ppp_recv(ppp, frame); /* zero buffer */ memset(ppp->buffer, 0, BUFFERSZ); ppp->index = 0; continue; } } /* copy byte to buffer */ if (ppp->index < BUFFERSZ) ppp->buffer[ppp->index++] = data[pos]; } } static void ppp_record(GAtPPP *ppp, gboolean in, guint8 *data, guint16 length) { guint16 len = htons(length); guint32 ts; struct timeval now; unsigned char id; int err; if (ppp->record_fd < 0) return; gettimeofday(&now, NULL); ts = htonl(now.tv_sec & 0xffffffff); id = 0x07; err = write(ppp->record_fd, &id, 1); err = write(ppp->record_fd, &ts, 4); id = in ? 0x02 : 0x01; err = write(ppp->record_fd, &id, 1); err = write(ppp->record_fd, &len, 2); err = write(ppp->record_fd, data, length); } /* * transmit out through the lower layer interface * * infolen - length of the information part of the packet */ void ppp_transmit(GAtPPP *ppp, guint8 *packet, guint infolen) { guint8 *frame; guint framelen; GError *error = NULL; GIOStatus status; gsize bytes_written; /* * do the octet stuffing. Add 2 bytes to the infolen to * include the protocol field. */ frame = ppp_encode(ppp, packet, infolen + 2, &framelen); if (!frame) { g_printerr("Failed to encode packet to transmit\n"); return; } /* transmit through the lower layer interface */ /* * TBD - should we just put this on a queue and transmit when * we won't block, or allow ourselves to block here? */ status = g_io_channel_write_chars(ppp->modem, (gchar *) frame, framelen, &bytes_written, &error); ppp_record(ppp, FALSE, frame, bytes_written); g_free(frame); } gboolean ppp_cb(GIOChannel *channel, GIOCondition cond, gpointer data) { GAtPPP *ppp = data; GIOStatus status; gchar buf[256]; gsize bytes_read; GError *error = NULL; if (cond & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) return FALSE; if (cond & G_IO_IN) { status = g_io_channel_read_chars(channel, buf, 256, &bytes_read, &error); if (bytes_read > 0) { ppp_record(ppp, TRUE, (guint8 *) buf, bytes_read); ppp_feed(ppp, (guint8 *) buf, bytes_read); } if (status != G_IO_STATUS_NORMAL && status != G_IO_STATUS_AGAIN) return FALSE; } return TRUE; } /* Administrative Close */ void ppp_close(GAtPPP *ppp) { /* send a CLOSE event to the lcp layer */ lcp_close(ppp->lcp); } static void ppp_link_establishment(GAtPPP *ppp) { /* signal UP event to LCP */ lcp_establish(ppp->lcp); } static void ppp_terminate(GAtPPP *ppp) { /* signal DOWN event to LCP */ lcp_terminate(ppp->lcp); } static void ppp_authenticate(GAtPPP *ppp) { /* we don't do authentication right now, so send NONE */ if (!ppp->auth_proto) ppp_generate_event(ppp, PPP_NONE); /* otherwise we need to wait for the peer to send us a challenge */ } static void ppp_dead(GAtPPP *ppp) { /* notify interested parties */ if (ppp->disconnect_cb) ppp->disconnect_cb(ppp->disconnect_data); if (g_atomic_int_get(&ppp->ref_count)) return; /* cleanup modem channel */ g_source_remove(ppp->modem_watch); g_io_channel_unref(ppp->modem); /* remove lcp */ lcp_free(ppp->lcp); /* remove auth */ auth_free(ppp->auth); g_free(ppp); } static void ppp_network(GAtPPP *ppp) { /* bring network phase up */ ppp_net_open(ppp->net); } static void ppp_transition_phase(GAtPPP *ppp, enum ppp_phase phase) { /* don't do anything if we're already there */ if (ppp->phase == phase) return; /* set new phase */ ppp->phase = phase; switch (phase) { case PPP_ESTABLISHMENT: ppp_link_establishment(ppp); break; case PPP_AUTHENTICATION: ppp_authenticate(ppp); break; case PPP_TERMINATION: ppp_terminate(ppp); break; case PPP_DEAD: ppp_dead(ppp); break; case PPP_NETWORK: ppp_network(ppp); break; } } /* * send the event handler a new event to process */ void ppp_generate_event(GAtPPP *ppp, enum ppp_event event) { switch (event) { case PPP_UP: /* causes transition to ppp establishment */ ppp_transition_phase(ppp, PPP_ESTABLISHMENT); break; case PPP_OPENED: ppp_transition_phase(ppp, PPP_AUTHENTICATION); break; case PPP_CLOSING: /* causes transition to termination phase */ ppp_transition_phase(ppp, PPP_TERMINATION); break; case PPP_DOWN: /* cases transition to dead phase */ ppp_transition_phase(ppp, PPP_DEAD); break; case PPP_NONE: case PPP_SUCCESS: /* causes transition to network phase */ ppp_transition_phase(ppp, PPP_NETWORK); break; case PPP_FAIL: if (ppp->phase == PPP_ESTABLISHMENT) ppp_transition_phase(ppp, PPP_DEAD); else if (ppp->phase == PPP_AUTHENTICATION) ppp_transition_phase(ppp, PPP_TERMINATION); } } void ppp_set_auth(GAtPPP *ppp, guint8* auth_data) { guint16 proto = get_host_short(auth_data); switch (proto) { case CHAP_PROTOCOL: /* get the algorithm */ auth_set_proto(ppp->auth, proto, auth_data[2]); break; default: g_printerr("unknown authentication proto\n"); break; } } void ppp_set_recv_accm(GAtPPP *ppp, guint32 accm) { ppp->recv_accm = accm; } guint32 ppp_get_xmit_accm(GAtPPP *ppp) { return ppp->xmit_accm[0]; } void ppp_set_pfc(GAtPPP *ppp, gboolean pfc) { ppp->pfc = pfc; } gboolean ppp_get_pfc(GAtPPP *ppp) { return ppp->pfc; } void ppp_set_acfc(GAtPPP *ppp, gboolean acfc) { ppp->acfc = acfc; } gboolean ppp_get_acfc(GAtPPP *ppp) { return ppp->acfc; } /* Administrative Open */ void g_at_ppp_open(GAtPPP *ppp) { /* send an OPEN event to the lcp layer */ lcp_open(ppp->lcp); } void g_at_ppp_set_credentials(GAtPPP *ppp, const char *username, const char *passwd) { auth_set_credentials(ppp->auth, username, passwd); } void g_at_ppp_set_connect_function(GAtPPP *ppp, GAtPPPConnectFunc func, gpointer user_data) { if (func == NULL) return; ppp->connect_cb = func; ppp->connect_data = user_data; } void g_at_ppp_set_disconnect_function(GAtPPP *ppp, GAtDisconnectFunc func, gpointer user_data) { if (func == NULL) return; ppp->disconnect_cb = func; ppp->disconnect_data = user_data; } void g_at_ppp_set_debug(GAtPPP *ppp, GAtDebugFunc func, gpointer user_data) { if (ppp == NULL) return; ppp->debugf = func; ppp->debug_data = user_data; } void g_at_ppp_set_recording(GAtPPP *ppp, const char *filename) { if (ppp == NULL) return; if (ppp->record_fd > fileno(stderr)) close(ppp->record_fd); if (filename == NULL) return; ppp->record_fd = open(filename, O_WRONLY | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); } void g_at_ppp_shutdown(GAtPPP *ppp) { /* close the ppp link */ ppp_close(ppp); } void g_at_ppp_ref(GAtPPP *ppp) { g_atomic_int_inc(&ppp->ref_count); } void g_at_ppp_unref(GAtPPP *ppp) { if (g_atomic_int_dec_and_test(&ppp->ref_count)) g_at_ppp_shutdown(ppp); /* * we can't free the link yet, because we need to terminate * the link first. */ if (ppp->record_fd > fileno(stderr)) close(ppp->record_fd); } GAtPPP *g_at_ppp_new(GIOChannel *modem) { GAtPPP *ppp; ppp = g_try_malloc0(sizeof(GAtPPP)); if (!ppp) return NULL; ppp->modem = g_io_channel_ref(modem); if (!g_at_util_setup_io(ppp->modem, G_IO_FLAG_NONBLOCK)) { g_io_channel_unref(modem); g_free(ppp); return NULL; } g_io_channel_set_buffered(modem, FALSE); ppp->ref_count = 1; /* set options to defaults */ ppp->mru = DEFAULT_MRU; ppp->recv_accm = DEFAULT_ACCM; ppp->xmit_accm[0] = DEFAULT_ACCM; ppp->xmit_accm[3] = 0x60000000; /* 0x7d, 0x7e */ ppp->pfc = FALSE; ppp->acfc = FALSE; ppp->index = 0; /* initialize the lcp state */ ppp->lcp = lcp_new(ppp); /* initialize the autentication state */ ppp->auth = auth_new(ppp); /* intialize the network state */ ppp->net = ppp_net_new(ppp); /* start listening for packets from the modem */ ppp->modem_watch = g_io_add_watch(modem, G_IO_IN | G_IO_HUP | G_IO_ERR | G_IO_NVAL, ppp_cb, ppp); ppp->record_fd = -1; return ppp; }