Rostislav Lisovy | 7b5f30e | 2012-08-20 13:11:55 -0700 | [diff] [blame] | 1 | /* |
| 2 | * em_canid.c Ematch rule to match CAN frames according to their CAN identifiers |
| 3 | * |
| 4 | * This program is free software; you can distribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version |
| 7 | * 2 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * Idea: Oliver Hartkopp <oliver.hartkopp@volkswagen.de> |
| 10 | * Copyright: (c) 2011 Czech Technical University in Prague |
| 11 | * (c) 2011 Volkswagen Group Research |
| 12 | * Authors: Michal Sojka <sojkam1@fel.cvut.cz> |
| 13 | * Pavel Pisa <pisa@cmp.felk.cvut.cz> |
| 14 | * Rostislav Lisovy <lisovy@gmail.cz> |
| 15 | * Funded by: Volkswagen Group Research |
| 16 | * |
| 17 | * Documentation: http://rtime.felk.cvut.cz/can/socketcan-qdisc-final.pdf |
| 18 | */ |
| 19 | |
| 20 | #include <stdio.h> |
| 21 | #include <stdlib.h> |
| 22 | #include <unistd.h> |
| 23 | #include <syslog.h> |
| 24 | #include <fcntl.h> |
| 25 | #include <sys/socket.h> |
| 26 | #include <netinet/in.h> |
| 27 | #include <arpa/inet.h> |
| 28 | #include <string.h> |
| 29 | #include <errno.h> |
| 30 | #include <linux/can.h> |
| 31 | #include <inttypes.h> |
| 32 | #include "m_ematch.h" |
| 33 | |
| 34 | #define EM_CANID_RULES_MAX 400 /* Main reason for this number is Nelink |
| 35 | message size limit equal to Single memory page size. When dump() |
| 36 | is invoked, there are even some ematch related headers sent from |
| 37 | kernel to userspace together with em_canid configuration -- |
| 38 | 400*sizeof(struct can_filter) should fit without any problems */ |
| 39 | |
| 40 | extern struct ematch_util canid_ematch_util; |
| 41 | struct rules { |
| 42 | struct can_filter *rules_raw; |
| 43 | int rules_capacity; /* Size of array allocated for rules_raw */ |
| 44 | int rules_cnt; /* Actual number of rules stored in rules_raw */ |
| 45 | }; |
| 46 | |
| 47 | static void canid_print_usage(FILE *fd) |
| 48 | { |
| 49 | fprintf(fd, |
| 50 | "Usage: canid(IDLIST)\n" \ |
| 51 | "where: IDLIST := IDSPEC [ IDLIST ]\n" \ |
| 52 | " IDSPEC := { ’sff’ CANID | ’eff’ CANID }\n" \ |
| 53 | " CANID := ID[:MASK]\n" \ |
| 54 | " ID, MASK := hexadecimal number (i.e. 0x123)\n" \ |
| 55 | "Example: canid(sff 0x123 sff 0x124 sff 0x125:0xf)\n"); |
| 56 | } |
| 57 | |
| 58 | static int canid_parse_rule(struct rules *rules, struct bstr *a, int iseff) |
| 59 | { |
| 60 | unsigned int can_id = 0; |
| 61 | unsigned int can_mask = 0; |
| 62 | |
| 63 | if (sscanf(a->data, "%"SCNx32 ":" "%"SCNx32, &can_id, &can_mask) != 2) { |
| 64 | if (sscanf(a->data, "%"SCNx32, &can_id) != 1) { |
| 65 | return -1; |
| 66 | } else { |
| 67 | can_mask = (iseff) ? CAN_EFF_MASK : CAN_SFF_MASK; |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | /* Stretch rules array up to EM_CANID_RULES_MAX if necessary */ |
| 72 | if (rules->rules_cnt == rules->rules_capacity) { |
| 73 | if (rules->rules_capacity <= EM_CANID_RULES_MAX/2) { |
| 74 | rules->rules_capacity *= 2; |
| 75 | rules->rules_raw = realloc(rules->rules_raw, |
| 76 | sizeof(struct can_filter) * rules->rules_capacity); |
| 77 | } else { |
| 78 | return -2; |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | rules->rules_raw[rules->rules_cnt].can_id = |
| 83 | can_id | ((iseff) ? CAN_EFF_FLAG : 0); |
| 84 | rules->rules_raw[rules->rules_cnt].can_mask = |
| 85 | can_mask | CAN_EFF_FLAG; |
| 86 | |
| 87 | rules->rules_cnt++; |
| 88 | |
| 89 | return 0; |
| 90 | } |
| 91 | |
| 92 | static int canid_parse_eopt(struct nlmsghdr *n, struct tcf_ematch_hdr *hdr, |
| 93 | struct bstr *args) |
| 94 | { |
| 95 | int iseff = 0; |
| 96 | int ret = 0; |
| 97 | struct rules rules = { |
| 98 | .rules_capacity = 25, /* Denominator of EM_CANID_RULES_MAX |
| 99 | Will be multiplied by 2 to calculate the size for realloc() */ |
| 100 | .rules_cnt = 0 |
| 101 | }; |
| 102 | |
| 103 | #define PARSE_ERR(CARG, FMT, ARGS...) \ |
| 104 | em_parse_error(EINVAL, args, CARG, &canid_ematch_util, FMT, ##ARGS) |
| 105 | |
| 106 | if (args == NULL) |
| 107 | return PARSE_ERR(args, "canid: missing arguments"); |
| 108 | |
Phil Sutter | f89bb02 | 2016-07-18 16:48:43 +0200 | [diff] [blame] | 109 | rules.rules_raw = calloc(rules.rules_capacity, |
| 110 | sizeof(struct can_filter)); |
Rostislav Lisovy | 7b5f30e | 2012-08-20 13:11:55 -0700 | [diff] [blame] | 111 | |
| 112 | do { |
| 113 | if (!bstrcmp(args, "sff")) { |
| 114 | iseff = 0; |
| 115 | } else if (!bstrcmp(args, "eff")) { |
| 116 | iseff = 1; |
| 117 | } else { |
| 118 | ret = PARSE_ERR(args, "canid: invalid key"); |
| 119 | goto exit; |
| 120 | } |
| 121 | |
| 122 | args = bstr_next(args); |
| 123 | if (args == NULL) { |
| 124 | ret = PARSE_ERR(args, "canid: missing argument"); |
| 125 | goto exit; |
| 126 | } |
| 127 | |
| 128 | ret = canid_parse_rule(&rules, args, iseff); |
| 129 | if (ret == -1) { |
| 130 | ret = PARSE_ERR(args, "canid: Improperly formed CAN ID & mask\n"); |
| 131 | goto exit; |
| 132 | } else if (ret == -2) { |
| 133 | ret = PARSE_ERR(args, "canid: Too many arguments on input\n"); |
| 134 | goto exit; |
| 135 | } |
| 136 | } while ((args = bstr_next(args)) != NULL); |
| 137 | |
| 138 | addraw_l(n, MAX_MSG, hdr, sizeof(*hdr)); |
| 139 | addraw_l(n, MAX_MSG, rules.rules_raw, |
| 140 | sizeof(struct can_filter) * rules.rules_cnt); |
| 141 | |
| 142 | #undef PARSE_ERR |
| 143 | exit: |
| 144 | free(rules.rules_raw); |
| 145 | return ret; |
| 146 | } |
| 147 | |
| 148 | static int canid_print_eopt(FILE *fd, struct tcf_ematch_hdr *hdr, void *data, |
| 149 | int data_len) |
| 150 | { |
| 151 | struct can_filter *conf = data; /* Array with rules */ |
| 152 | int rules_count; |
| 153 | int i; |
| 154 | |
| 155 | rules_count = data_len / sizeof(struct can_filter); |
| 156 | |
| 157 | for (i = 0; i < rules_count; i++) { |
| 158 | struct can_filter *pcfltr = &conf[i]; |
| 159 | |
| 160 | if (pcfltr->can_id & CAN_EFF_FLAG) { |
| 161 | if (pcfltr->can_mask == (CAN_EFF_FLAG | CAN_EFF_MASK)) |
| 162 | fprintf(fd, "eff 0x%"PRIX32, |
| 163 | pcfltr->can_id & CAN_EFF_MASK); |
| 164 | else |
| 165 | fprintf(fd, "eff 0x%"PRIX32":0x%"PRIX32, |
| 166 | pcfltr->can_id & CAN_EFF_MASK, |
| 167 | pcfltr->can_mask & CAN_EFF_MASK); |
| 168 | } else { |
| 169 | if (pcfltr->can_mask == (CAN_EFF_FLAG | CAN_SFF_MASK)) |
| 170 | fprintf(fd, "sff 0x%"PRIX32, |
| 171 | pcfltr->can_id & CAN_SFF_MASK); |
| 172 | else |
| 173 | fprintf(fd, "sff 0x%"PRIX32":0x%"PRIX32, |
| 174 | pcfltr->can_id & CAN_SFF_MASK, |
| 175 | pcfltr->can_mask & CAN_SFF_MASK); |
| 176 | } |
| 177 | |
| 178 | if ((i + 1) < rules_count) |
| 179 | fprintf(fd, " "); |
| 180 | } |
| 181 | |
| 182 | return 0; |
| 183 | } |
| 184 | |
| 185 | struct ematch_util canid_ematch_util = { |
| 186 | .kind = "canid", |
| 187 | .kind_num = TCF_EM_CANID, |
| 188 | .parse_eopt = canid_parse_eopt, |
| 189 | .print_eopt = canid_print_eopt, |
| 190 | .print_usage = canid_print_usage |
| 191 | }; |