Harald Welte | 51b00a6 | 2014-04-03 09:37:38 -0400 | [diff] [blame] | 1 | /* Generic Netlink helper functions */ |
| 2 | |
| 3 | /* (C) 2014 by sysmocom - s.f.m.c. GmbH |
| 4 | * Author: Pablo Neira Ayuso <pablo@gnumonks.org> |
| 5 | * |
| 6 | * All Rights Reserved |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
Harald Welte | d2bb0bc | 2016-07-28 20:34:45 +0200 | [diff] [blame] | 9 | * it under the terms of the GNU Lesser General Public License as |
| 10 | * published by the Free Software Foundation; either version 2.1 of the |
| 11 | * License, or (at your option) any later version. |
Harald Welte | 51b00a6 | 2014-04-03 09:37:38 -0400 | [diff] [blame] | 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
Harald Welte | d2bb0bc | 2016-07-28 20:34:45 +0200 | [diff] [blame] | 16 | * GNU Lesser General Public License for more details. |
Harald Welte | 51b00a6 | 2014-04-03 09:37:38 -0400 | [diff] [blame] | 17 | * |
Harald Welte | d2bb0bc | 2016-07-28 20:34:45 +0200 | [diff] [blame] | 18 | * You should have received a copy of the GNU Lesser General Public License |
Harald Welte | 51b00a6 | 2014-04-03 09:37:38 -0400 | [diff] [blame] | 19 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 20 | * |
| 21 | */ |
| 22 | |
Pablo Neira Ayuso | 1450666 | 2014-02-20 18:43:15 +0100 | [diff] [blame] | 23 | #include <stdio.h> |
| 24 | #include <stdlib.h> |
| 25 | #include <unistd.h> |
| 26 | #include <time.h> |
| 27 | |
| 28 | #include <libmnl/libmnl.h> |
| 29 | #include <linux/genetlink.h> |
| 30 | |
| 31 | #include <libgtpnl/gtpnl.h> |
| 32 | |
| 33 | #include "internal.h" |
| 34 | |
| 35 | struct nlmsghdr * |
| 36 | genl_nlmsg_build_hdr(char *buf, uint16_t type, uint16_t flags, uint32_t seq, |
| 37 | uint8_t cmd) |
| 38 | { |
| 39 | struct nlmsghdr *nlh; |
| 40 | struct genlmsghdr *genl; |
| 41 | |
| 42 | nlh = mnl_nlmsg_put_header(buf); |
| 43 | nlh->nlmsg_type = type; |
| 44 | nlh->nlmsg_flags = NLM_F_REQUEST | flags; |
| 45 | nlh->nlmsg_seq = seq; |
| 46 | |
| 47 | genl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr)); |
| 48 | genl->cmd = cmd; |
| 49 | genl->version = 0; |
| 50 | |
| 51 | return nlh; |
| 52 | } |
| 53 | EXPORT_SYMBOL(genl_nlmsg_build_hdr); |
| 54 | |
| 55 | static int genl_ctrl_validate_cb(const struct nlattr *attr, void *data) |
| 56 | { |
| 57 | const struct nlattr **tb = data; |
| 58 | int type = mnl_attr_get_type(attr); |
| 59 | |
| 60 | if (mnl_attr_type_valid(attr, CTRL_ATTR_MAX) < 0) |
| 61 | return MNL_CB_OK; |
| 62 | |
| 63 | switch(type) { |
| 64 | case CTRL_ATTR_FAMILY_ID: |
| 65 | if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0) { |
| 66 | perror("mnl_attr_validate"); |
| 67 | return MNL_CB_ERROR; |
| 68 | } |
| 69 | break; |
| 70 | } |
| 71 | tb[type] = attr; |
| 72 | return MNL_CB_OK; |
| 73 | } |
| 74 | |
| 75 | static int genl_ctrl_cb(const struct nlmsghdr *nlh, void *data) |
| 76 | { |
| 77 | struct nlattr *tb[CTRL_ATTR_MAX + 1] = {}; |
| 78 | struct genlmsghdr *genl = mnl_nlmsg_get_payload(nlh); |
| 79 | int32_t *genl_id = data; |
| 80 | |
| 81 | mnl_attr_parse(nlh, sizeof(*genl), genl_ctrl_validate_cb, tb); |
| 82 | if (tb[CTRL_ATTR_FAMILY_ID]) |
| 83 | *genl_id = mnl_attr_get_u16(tb[CTRL_ATTR_FAMILY_ID]); |
| 84 | else |
| 85 | *genl_id = -1; |
| 86 | |
| 87 | return MNL_CB_OK; |
| 88 | } |
| 89 | |
| 90 | struct mnl_socket *genl_socket_open(void) |
| 91 | { |
| 92 | struct mnl_socket *nl; |
| 93 | |
| 94 | nl = mnl_socket_open(NETLINK_GENERIC); |
| 95 | if (nl == NULL) { |
| 96 | perror("mnl_socket_open"); |
| 97 | return NULL; |
| 98 | } |
| 99 | |
| 100 | if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) { |
| 101 | perror("mnl_socket_bind"); |
| 102 | return NULL; |
| 103 | } |
| 104 | |
| 105 | return nl; |
| 106 | } |
| 107 | EXPORT_SYMBOL(genl_socket_open); |
| 108 | |
| 109 | int genl_socket_talk(struct mnl_socket *nl, struct nlmsghdr *nlh, uint32_t seq, |
| 110 | int (*cb)(const struct nlmsghdr *nlh, void *data), |
| 111 | void *data) |
| 112 | { |
| 113 | char buf[MNL_SOCKET_BUFFER_SIZE]; |
| 114 | int ret; |
| 115 | |
| 116 | if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { |
| 117 | perror("mnl_socket_send"); |
| 118 | return -1; |
| 119 | } |
| 120 | |
| 121 | ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); |
| 122 | while (ret > 0) { |
| 123 | ret = mnl_cb_run(buf, ret, seq, mnl_socket_get_portid(nl), |
| 124 | cb, data); |
| 125 | if (ret <= 0) |
| 126 | break; |
| 127 | ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); |
| 128 | } |
| 129 | |
| 130 | return ret; |
| 131 | } |
| 132 | EXPORT_SYMBOL(genl_socket_talk); |
| 133 | |
| 134 | static struct nlmsghdr * |
| 135 | genl_nlmsg_build_lookup(char *buf, const char *subsys_name) |
| 136 | { |
| 137 | struct nlmsghdr *nlh; |
| 138 | struct genlmsghdr *genl; |
| 139 | |
| 140 | nlh = mnl_nlmsg_put_header(buf); |
| 141 | nlh->nlmsg_type = GENL_ID_CTRL; |
| 142 | nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; |
| 143 | nlh->nlmsg_seq = time(NULL); |
| 144 | |
| 145 | genl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr)); |
| 146 | genl->cmd = CTRL_CMD_GETFAMILY; |
| 147 | genl->version = 1; |
| 148 | |
| 149 | mnl_attr_put_u32(nlh, CTRL_ATTR_FAMILY_ID, GENL_ID_CTRL); |
| 150 | mnl_attr_put_strz(nlh, CTRL_ATTR_FAMILY_NAME, subsys_name); |
| 151 | |
| 152 | return nlh; |
| 153 | } |
| 154 | |
| 155 | int genl_lookup_family(struct mnl_socket *nl, const char *family) |
| 156 | { |
| 157 | int32_t genl_id; |
| 158 | char buf[MNL_SOCKET_BUFFER_SIZE]; |
| 159 | struct nlmsghdr *nlh = genl_nlmsg_build_lookup(buf, "gtp"); |
| 160 | int err; |
| 161 | |
| 162 | err = genl_socket_talk(nl, nlh, nlh->nlmsg_seq, genl_ctrl_cb, &genl_id); |
| 163 | if (err < 0) |
| 164 | return -1; |
| 165 | |
| 166 | return genl_id; |
| 167 | } |
| 168 | EXPORT_SYMBOL(genl_lookup_family); |