diff options
Diffstat (limited to 'tc/em_meta.c')
| -rw-r--r-- | tc/em_meta.c | 541 |
1 files changed, 541 insertions, 0 deletions
diff --git a/tc/em_meta.c b/tc/em_meta.c new file mode 100644 index 0000000..6a5654f --- /dev/null +++ b/tc/em_meta.c @@ -0,0 +1,541 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * em_meta.c Metadata Ematch + * + * Authors: Thomas Graf <tgraf@suug.ch> + */ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <arpa/inet.h> +#include <string.h> +#include <errno.h> + +#include "m_ematch.h" +#include <linux/tc_ematch/tc_em_meta.h> + +extern struct ematch_util meta_ematch_util; + +static void meta_print_usage(FILE *fd) +{ + fprintf(fd, + "Usage: meta(OBJECT { eq | lt | gt } OBJECT)\n" \ + "where: OBJECT := { META_ID | VALUE }\n" \ + " META_ID := id [ shift SHIFT ] [ mask MASK ]\n" \ + "\n" \ + "Example: meta(nf_mark gt 24)\n" \ + " meta(indev shift 1 eq \"ppp\")\n" \ + " meta(tcindex mask 0xf0 eq 0xf0)\n" \ + "\n" \ + "For a list of meta identifiers, use meta(list).\n"); +} + +static const struct meta_entry { + int id; + char *kind; + char *mask; + char *desc; +} meta_table[] = { +#define TCF_META_ID_SECTION 0 +#define __A(id, name, mask, desc) { TCF_META_ID_##id, name, mask, desc } + __A(SECTION, "Generic", "", ""), + __A(RANDOM, "random", "i", + "Random value (32 bit)"), + __A(LOADAVG_0, "loadavg_1", "i", + "Load average in last minute"), + __A(LOADAVG_1, "loadavg_5", "i", + "Load average in last 5 minutes"), + __A(LOADAVG_2, "loadavg_15", "i", + "Load average in last 15 minutes"), + + __A(SECTION, "Interfaces", "", ""), + __A(DEV, "dev", "iv", + "Device the packet is on"), + __A(SECTION, "Packet attributes", "", ""), + __A(PRIORITY, "priority", "i", + "Priority of packet"), + __A(PROTOCOL, "protocol", "i", + "Link layer protocol"), + __A(PKTTYPE, "pkt_type", "i", + "Packet type (uni|multi|broad|...)cast"), + __A(PKTLEN, "pkt_len", "i", + "Length of packet"), + __A(DATALEN, "data_len", "i", + "Length of data in packet"), + __A(MACLEN, "mac_len", "i", + "Length of link layer header"), + + __A(SECTION, "Netfilter", "", ""), + __A(NFMARK, "nf_mark", "i", + "Netfilter mark"), + __A(NFMARK, "fwmark", "i", + "Alias for nf_mark"), + + __A(SECTION, "Traffic Control", "", ""), + __A(TCINDEX, "tc_index", "i", "TC Index"), + __A(SECTION, "Routing", "", ""), + __A(RTCLASSID, "rt_classid", "i", + "Routing ClassID (cls_route)"), + __A(RTIIF, "rt_iif", "i", + "Incoming interface index"), + __A(VLAN_TAG, "vlan", "i", "Vlan tag"), + + __A(SECTION, "Sockets", "", ""), + __A(SK_FAMILY, "sk_family", "i", "Address family"), + __A(SK_STATE, "sk_state", "i", "State"), + __A(SK_REUSE, "sk_reuse", "i", "Reuse Flag"), + __A(SK_BOUND_IF, "sk_bind_if", "iv", "Bound interface"), + __A(SK_REFCNT, "sk_refcnt", "i", "Reference counter"), + __A(SK_SHUTDOWN, "sk_shutdown", "i", "Shutdown mask"), + __A(SK_PROTO, "sk_proto", "i", "Protocol"), + __A(SK_TYPE, "sk_type", "i", "Type"), + __A(SK_RCVBUF, "sk_rcvbuf", "i", "Receive buffer size"), + __A(SK_RMEM_ALLOC, "sk_rmem", "i", "RMEM"), + __A(SK_WMEM_ALLOC, "sk_wmem", "i", "WMEM"), + __A(SK_OMEM_ALLOC, "sk_omem", "i", "OMEM"), + __A(SK_WMEM_QUEUED, "sk_wmem_queue", "i", "WMEM queue"), + __A(SK_SND_QLEN, "sk_snd_queue", "i", "Send queue length"), + __A(SK_RCV_QLEN, "sk_rcv_queue", "i", "Receive queue length"), + __A(SK_ERR_QLEN, "sk_err_queue", "i", "Error queue length"), + __A(SK_FORWARD_ALLOCS, "sk_fwd_alloc", "i", "Forward allocations"), + __A(SK_SNDBUF, "sk_sndbuf", "i", "Send buffer size"), +#undef __A +}; + +static inline int map_type(char k) +{ + switch (k) { + case 'i': return TCF_META_TYPE_INT; + case 'v': return TCF_META_TYPE_VAR; + } + + fprintf(stderr, "BUG: Unknown map character '%c'\n", k); + return INT_MAX; +} + +static const struct meta_entry *lookup_meta_entry(struct bstr *kind) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(meta_table); i++) + if (!bstrcmp(kind, meta_table[i].kind) && + meta_table[i].id != 0) + return &meta_table[i]; + + return NULL; +} + +static const struct meta_entry *lookup_meta_entry_byid(int id) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(meta_table); i++) + if (meta_table[i].id == id) + return &meta_table[i]; + + return NULL; +} + +static inline void dump_value(struct nlmsghdr *n, int tlv, unsigned long val, + struct tcf_meta_val *hdr) +{ + __u32 t; + + switch (TCF_META_TYPE(hdr->kind)) { + case TCF_META_TYPE_INT: + t = val; + addattr_l(n, MAX_MSG, tlv, &t, sizeof(t)); + break; + + case TCF_META_TYPE_VAR: + if (TCF_META_ID(hdr->kind) == TCF_META_ID_VALUE) { + struct bstr *a = (struct bstr *) val; + + addattr_l(n, MAX_MSG, tlv, a->data, a->len); + } + break; + } +} + +static inline int is_compatible(struct tcf_meta_val *what, + struct tcf_meta_val *needed) +{ + const struct meta_entry *entry; + char *p; + + entry = lookup_meta_entry_byid(TCF_META_ID(what->kind)); + + if (entry == NULL) + return 0; + + for (p = entry->mask; p; p++) + if (map_type(*p) == TCF_META_TYPE(needed->kind)) + return 1; + + return 0; +} + +static void list_meta_ids(FILE *fd) +{ + int i; + + fprintf(fd, + "--------------------------------------------------------\n" \ + " ID Type Description\n" \ + "--------------------------------------------------------"); + + for (i = 0; i < ARRAY_SIZE(meta_table); i++) { + if (meta_table[i].id == TCF_META_ID_SECTION) { + fprintf(fd, "\n%s:\n", meta_table[i].kind); + } else { + char *p = meta_table[i].mask; + char buf[64] = {0}; + + fprintf(fd, " %-16s ", meta_table[i].kind); + + while (*p) { + int type = map_type(*p); + + switch (type) { + case TCF_META_TYPE_INT: + strcat(buf, "INT"); + break; + + case TCF_META_TYPE_VAR: + strcat(buf, "VAR"); + break; + } + + if (*(++p)) + strcat(buf, ","); + } + + fprintf(fd, "%-10s %s\n", buf, meta_table[i].desc); + } + } + + fprintf(fd, + "--------------------------------------------------------\n"); +} + +#undef TCF_META_ID_SECTION + +#define PARSE_FAILURE ((void *) (-1)) + +#define PARSE_ERR(CARG, FMT, ARGS...) \ + em_parse_error(EINVAL, args, CARG, &meta_ematch_util, FMT, ##ARGS) + +static inline int can_adopt(struct tcf_meta_val *val) +{ + return !!TCF_META_ID(val->kind); +} + +static inline int overwrite_type(struct tcf_meta_val *src, + struct tcf_meta_val *dst) +{ + return (TCF_META_TYPE(dst->kind) << 12) | TCF_META_ID(src->kind); +} + + +static inline struct bstr * +parse_object(struct bstr *args, struct bstr *arg, struct tcf_meta_val *obj, + unsigned long *dst, struct tcf_meta_val *left) +{ + const struct meta_entry *entry; + unsigned long num; + struct bstr *a; + + if (arg->quoted) { + obj->kind = TCF_META_TYPE_VAR << 12; + obj->kind |= TCF_META_ID_VALUE; + *dst = (unsigned long) arg; + return bstr_next(arg); + } + + num = bstrtoul(arg); + if (num != ULONG_MAX) { + obj->kind = TCF_META_TYPE_INT << 12; + obj->kind |= TCF_META_ID_VALUE; + *dst = (unsigned long) num; + return bstr_next(arg); + } + + entry = lookup_meta_entry(arg); + + if (entry == NULL) { + PARSE_ERR(arg, "meta: unknown meta id\n"); + return PARSE_FAILURE; + } + + obj->kind = entry->id | (map_type(entry->mask[0]) << 12); + + if (left) { + struct tcf_meta_val *right = obj; + + if (TCF_META_TYPE(right->kind) == TCF_META_TYPE(left->kind)) + goto compatible; + + if (can_adopt(left) && !can_adopt(right)) { + if (is_compatible(left, right)) + left->kind = overwrite_type(left, right); + else + goto not_compatible; + } else if (can_adopt(right) && !can_adopt(left)) { + if (is_compatible(right, left)) + right->kind = overwrite_type(right, left); + else + goto not_compatible; + } else if (can_adopt(left) && can_adopt(right)) { + if (is_compatible(left, right)) + left->kind = overwrite_type(left, right); + else if (is_compatible(right, left)) + right->kind = overwrite_type(right, left); + else + goto not_compatible; + } else + goto not_compatible; + } + +compatible: + + a = bstr_next(arg); + + while (a) { + if (!bstrcmp(a, "shift")) { + unsigned long shift; + + if (a->next == NULL) { + PARSE_ERR(a, "meta: missing argument"); + return PARSE_FAILURE; + } + a = bstr_next(a); + + shift = bstrtoul(a); + if (shift == ULONG_MAX) { + PARSE_ERR(a, "meta: invalid shift, must " \ + "be numeric"); + return PARSE_FAILURE; + } + + obj->shift = (__u8) shift; + a = bstr_next(a); + } else if (!bstrcmp(a, "mask")) { + unsigned long mask; + + if (a->next == NULL) { + PARSE_ERR(a, "meta: missing argument"); + return PARSE_FAILURE; + } + a = bstr_next(a); + + mask = bstrtoul(a); + if (mask == ULONG_MAX) { + PARSE_ERR(a, "meta: invalid mask, must be " \ + "numeric"); + return PARSE_FAILURE; + } + *dst = (unsigned long) mask; + a = bstr_next(a); + } else + break; + } + + return a; + +not_compatible: + PARSE_ERR(arg, "lvalue and rvalue are not compatible."); + return PARSE_FAILURE; +} + +static int meta_parse_eopt(struct nlmsghdr *n, struct tcf_ematch_hdr *hdr, + struct bstr *args) +{ + int opnd; + struct bstr *a; + struct tcf_meta_hdr meta_hdr = {}; + unsigned long lvalue = 0, rvalue = 0; + + if (args == NULL) + return PARSE_ERR(args, "meta: missing arguments"); + + if (!bstrcmp(args, "list")) { + list_meta_ids(stderr); + return -1; + } + + a = parse_object(args, args, &meta_hdr.left, &lvalue, NULL); + if (a == PARSE_FAILURE) + return -1; + else if (a == NULL) + return PARSE_ERR(args, "meta: missing operand"); + + if (!bstrcmp(a, "eq")) + opnd = TCF_EM_OPND_EQ; + else if (!bstrcmp(a, "gt")) + opnd = TCF_EM_OPND_GT; + else if (!bstrcmp(a, "lt")) + opnd = TCF_EM_OPND_LT; + else + return PARSE_ERR(a, "meta: invalid operand"); + + meta_hdr.left.op = (__u8) opnd; + + if (a->next == NULL) + return PARSE_ERR(args, "meta: missing rvalue"); + a = bstr_next(a); + + a = parse_object(args, a, &meta_hdr.right, &rvalue, &meta_hdr.left); + if (a == PARSE_FAILURE) + return -1; + else if (a != NULL) + return PARSE_ERR(a, "meta: unexpected trailer"); + + + addraw_l(n, MAX_MSG, hdr, sizeof(*hdr)); + + addattr_l(n, MAX_MSG, TCA_EM_META_HDR, &meta_hdr, sizeof(meta_hdr)); + + dump_value(n, TCA_EM_META_LVALUE, lvalue, &meta_hdr.left); + dump_value(n, TCA_EM_META_RVALUE, rvalue, &meta_hdr.right); + + return 0; +} +#undef PARSE_ERR + +static inline void print_binary(FILE *fd, unsigned char *str, int len) +{ + int i; + + for (i = 0; i < len; i++) + if (!isprint(str[i])) + goto binary; + + for (i = 0; i < len; i++) + fprintf(fd, "%c", str[i]); + return; + +binary: + for (i = 0; i < len; i++) + fprintf(fd, "%02x ", str[i]); + + fprintf(fd, "\""); + for (i = 0; i < len; i++) + fprintf(fd, "%c", isprint(str[i]) ? str[i] : '.'); + fprintf(fd, "\""); +} + +static inline int print_value(FILE *fd, int type, struct rtattr *rta) +{ + if (rta == NULL) { + fprintf(stderr, "Missing value TLV\n"); + return -1; + } + + switch (type) { + case TCF_META_TYPE_INT: + if (RTA_PAYLOAD(rta) < sizeof(__u32)) { + fprintf(stderr, "meta int type value TLV " \ + "size mismatch.\n"); + return -1; + } + fprintf(fd, "%d", rta_getattr_u32(rta)); + break; + + case TCF_META_TYPE_VAR: + print_binary(fd, RTA_DATA(rta), RTA_PAYLOAD(rta)); + break; + } + + return 0; +} + +static int print_object(FILE *fd, struct tcf_meta_val *obj, struct rtattr *rta) +{ + int id = TCF_META_ID(obj->kind); + int type = TCF_META_TYPE(obj->kind); + const struct meta_entry *entry; + + if (id == TCF_META_ID_VALUE) + return print_value(fd, type, rta); + + entry = lookup_meta_entry_byid(id); + + if (entry == NULL) + fprintf(fd, "[unknown meta id %d]", id); + else + fprintf(fd, "%s", entry->kind); + + if (obj->shift) + fprintf(fd, " shift %d", obj->shift); + + switch (type) { + case TCF_META_TYPE_INT: + if (rta) { + if (RTA_PAYLOAD(rta) < sizeof(__u32)) + goto size_mismatch; + + if (rta_getattr_u32(rta)) + fprintf(fd, " mask 0x%08x", + rta_getattr_u32(rta)); + } + break; + } + + return 0; + +size_mismatch: + fprintf(stderr, "meta int type mask TLV size mismatch\n"); + return -1; +} + + +static int meta_print_eopt(FILE *fd, struct tcf_ematch_hdr *hdr, void *data, + int data_len) +{ + struct rtattr *tb[TCA_EM_META_MAX+1]; + struct tcf_meta_hdr *meta_hdr; + + if (parse_rtattr(tb, TCA_EM_META_MAX, data, data_len) < 0) + return -1; + + if (tb[TCA_EM_META_HDR] == NULL) { + fprintf(stderr, "Missing meta header\n"); + return -1; + } + + if (RTA_PAYLOAD(tb[TCA_EM_META_HDR]) < sizeof(*meta_hdr)) { + fprintf(stderr, "Meta header size mismatch\n"); + return -1; + } + + meta_hdr = RTA_DATA(tb[TCA_EM_META_HDR]); + + if (print_object(fd, &meta_hdr->left, tb[TCA_EM_META_LVALUE]) < 0) + return -1; + + switch (meta_hdr->left.op) { + case TCF_EM_OPND_EQ: + fprintf(fd, " eq "); + break; + case TCF_EM_OPND_LT: + fprintf(fd, " lt "); + break; + case TCF_EM_OPND_GT: + fprintf(fd, " gt "); + break; + } + + return print_object(fd, &meta_hdr->right, tb[TCA_EM_META_RVALUE]); +} + +struct ematch_util meta_ematch_util = { + .kind = "meta", + .kind_num = TCF_EM_META, + .parse_eopt = meta_parse_eopt, + .print_eopt = meta_print_eopt, + .print_usage = meta_print_usage +}; |