On Wed, Nov 13, 2013 at 11:22:33PM +0200, Patrik Flykt wrote: > Add functions to append and parse DHCP options. Not all options > are passed to the callback function, the ones not exposed are > pad, end, message type and overload. If indicated by the overload > option, file and sname fields will be examined for more options. > > The option functions are internal to DHCP, add a new header files > for interal function prototypes. > --- > src/dhcp/internal.h | 34 ++++++++++ > src/dhcp/option.c | 181 > +++++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 215 insertions(+) > create mode 100644 src/dhcp/internal.h > create mode 100644 src/dhcp/option.c > > diff --git a/src/dhcp/internal.h b/src/dhcp/internal.h > new file mode 100644 > index 0000000..65a3bb3 > --- /dev/null > +++ b/src/dhcp/internal.h > @@ -0,0 +1,34 @@ > +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ > + > +#pragma once > + > +/*** > + This file is part of systemd. > + > + Copyright (C) 2013 Intel Corporation. All rights reserved. > + > + systemd is free software; you can redistribute it and/or modify it > + under the terms of the GNU Lesser General Public License as published by > + the Free Software Foundation; either version 2.1 of the License, or > + (at your option) any later version. > + > + systemd 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 > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public License > + along with systemd; If not, see <http://www.gnu.org/licenses/>. > +***/ > + > +#include <stdint.h> > + > +#include "protocol.h" > + > +int __dhcp_option_append(uint8_t **buf, int *buflen, uint8_t code, > + uint8_t optlen, void *optval); > + > +typedef int (*dhcp_option_cb_t)(uint8_t code, uint8_t len, uint8_t *option, > + void *user_data); > +int __dhcp_option_parse(DHCPMessage *message, int32_t len, > + dhcp_option_cb_t cb, void *user_data); Why "__"?
> diff --git a/src/dhcp/option.c b/src/dhcp/option.c > new file mode 100644 > index 0000000..f5ca6e7 > --- /dev/null > +++ b/src/dhcp/option.c > @@ -0,0 +1,181 @@ > +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ > + > +/*** > + This file is part of systemd. > + > + Copyright (C) 2013 Intel Corporation. All rights reserved. > + > + systemd is free software; you can redistribute it and/or modify it > + under the terms of the GNU Lesser General Public License as published by > + the Free Software Foundation; either version 2.1 of the License, or > + (at your option) any later version. > + > + systemd 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 > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public License > + along with systemd; If not, see <http://www.gnu.org/licenses/>. > +***/ > + > +#include <stdint.h> > +#include <string.h> > +#include <errno.h> > +#include <stdio.h> > + > +#include "internal.h" > + > +int __dhcp_option_append(uint8_t **buf, int *buflen, uint8_t code, > + uint8_t optlen, void *optval) > +{ > + if (!buf || !buflen) > + return -EINVAL; > + > + switch (code) { > + > + case DHCP_OPTION_PAD: > + case DHCP_OPTION_END: > + if (*buflen < 1) > + return -ENOBUFS; > + > + (*buf)[0] = code; > + *buf += 1; > + *buflen -= 1; > + break; > + > + default: > + if (*buflen < optlen + 2) > + return -ENOBUFS; > + > + if (!optval) > + return -EINVAL; > + > + (*buf)[0] = code; > + (*buf)[1] = optlen; > + memcpy(&(*buf)[2], optval, optlen); > + > + *buf += optlen + 2; > + *buflen = *buflen - optlen - 2; > + > + break; > + } > + > + return 0; > +} > + > +static int parse_options(uint8_t *buf, int32_t buflen, int *overload, > + int *message_type, dhcp_option_cb_t cb, > + void *user_data) > +{ > + uint8_t *code = buf; > + uint8_t *len; > + > + while (buflen > 0) { > + switch (*code) { > + case DHCP_OPTION_PAD: > + buflen -= 1; > + code++; > + break; > + > + case DHCP_OPTION_END: > + return 0; > + > + case DHCP_OPTION_MESSAGE_TYPE: > + buflen -= 3; > + if (buflen < 0) > + return -ENOBUFS; > + > + len = code + 1; > + if (*len != 1) > + return -EINVAL; > + > + if (message_type) > + *message_type = *(len + 1); > + > + code = code + 3; > + > + break; > + > + case DHCP_OPTION_OVERLOAD: > + buflen -= 3; > + if (buflen < 0) > + return -ENOBUFS; > + > + len = code + 1; > + if (*len != 1) > + return -EINVAL; > + > + if (overload) > + *overload = *(len + 1); > + > + code = code + 3; code += 3; ? > + > + break; > + > + default: > + if (buflen < 3) > + return -ENOBUFS; > + > + len = code + 1; > + buflen -= *len + 2; > + > + if (buflen < 0) > + return -EINVAL; > + > + if (cb) > + cb(*code, *len, len + 1, user_data); > + > + code = code + *len + 2; code += *len + 2; ? > + > + break; > + } > + } > + > + if (buflen) > + return -EINVAL; > + > + return 0; > +} > + > +int __dhcp_option_parse(DHCPMessage *message, int32_t len, > + dhcp_option_cb_t cb, void *user_data) > +{ > + int overload = 0; > + int message_type = -ENOMSG; > + uint8_t *opt = (uint8_t *)(message + 1); > + int res; > + > + if (message == NULL || len < 0) > + return -EINVAL; > + > + len -= sizeof(DHCPMessage); > + len -= 4; > + if (len < 0) > + return -EINVAL; > + > + if (opt[0] != 0x63 && opt[1] != 0x82 && opt[2] != 0x53 && > + opt[3] != 0x63) > + return -EINVAL; > + > + res = parse_options(&opt[4], len, &overload, &message_type, > + cb, user_data); > + if (res < 0) > + return res; > + > + if (overload & DHCP_OVERLOAD_FILE) { > + res = parse_options(message->file, sizeof(message->file), > + NULL, &message_type, cb, user_data); > + if (res < 0) > + return res; > + } > + > + if (overload & DHCP_OVERLOAD_SNAME) { > + res = parse_options(message->sname, sizeof(message->sname), > + NULL, &message_type, cb, user_data); > + if (res < 0) > + return res; > + } > + > + return message_type; > +} Zbyszek _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
