| /* |
| * em_cmp.c Simple comparison Ematch |
| * |
| * This program is free software; you can distribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Authors: Thomas Graf <tgraf@suug.ch> |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <syslog.h> |
| #include <fcntl.h> |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| #include <string.h> |
| #include <dlfcn.h> |
| #include <errno.h> |
| |
| #include "m_ematch.h" |
| #include <linux/tc_ematch/tc_em_cmp.h> |
| |
| extern struct ematch_util cmp_ematch_util; |
| |
| static void cmp_print_usage(FILE *fd) |
| { |
| fprintf(fd, |
| "Usage: cmp(ALIGN at OFFSET [ ATTRS ] { eq | lt | gt } VALUE)\n" \ |
| "where: ALIGN := { u8 | u16 | u32 }\n" \ |
| " ATTRS := [ layer LAYER ] [ mask MASK ] [ trans ]\n" \ |
| " LAYER := { link | network | transport | 0..%d }\n" \ |
| "\n" \ |
| "Example: cmp(u16 at 3 layer 2 mask 0xff00 gt 20)\n", |
| TCF_LAYER_MAX); |
| } |
| |
| static int cmp_parse_eopt(struct nlmsghdr *n, struct tcf_ematch_hdr *hdr, |
| struct bstr *args) |
| { |
| struct bstr *a; |
| int align, opnd = 0; |
| unsigned long offset = 0, layer = TCF_LAYER_NETWORK, mask = 0, value = 0; |
| int offset_present = 0, value_present = 0; |
| struct tcf_em_cmp cmp; |
| |
| memset(&cmp, 0, sizeof(cmp)); |
| |
| #define PARSE_ERR(CARG, FMT, ARGS...) \ |
| em_parse_error(EINVAL, args, CARG, &cmp_ematch_util, FMT ,##ARGS) |
| |
| if (args == NULL) |
| return PARSE_ERR(args, "cmp: missing arguments"); |
| |
| if (!bstrcmp(args, "u8")) |
| align = TCF_EM_ALIGN_U8; |
| else if (!bstrcmp(args, "u16")) |
| align = TCF_EM_ALIGN_U16; |
| else if (!bstrcmp(args, "u32")) |
| align = TCF_EM_ALIGN_U32; |
| else |
| return PARSE_ERR(args, "cmp: invalid alignment"); |
| |
| for (a = bstr_next(args); a; a = bstr_next(a)) { |
| if (!bstrcmp(a, "at")) { |
| if (a->next == NULL) |
| return PARSE_ERR(a, "cmp: missing argument"); |
| a = bstr_next(a); |
| |
| offset = bstrtoul(a); |
| if (offset == ULONG_MAX) |
| return PARSE_ERR(a, "cmp: invalid offset, " \ |
| "must be numeric"); |
| |
| offset_present = 1; |
| } else if (!bstrcmp(a, "layer")) { |
| if (a->next == NULL) |
| return PARSE_ERR(a, "cmp: missing argument"); |
| a = bstr_next(a); |
| |
| layer = parse_layer(a); |
| if (layer == INT_MAX) { |
| layer = bstrtoul(a); |
| if (layer == ULONG_MAX) |
| return PARSE_ERR(a, "cmp: invalid " \ |
| "layer"); |
| } |
| |
| if (layer > TCF_LAYER_MAX) |
| return PARSE_ERR(a, "cmp: illegal layer, " \ |
| "must be in 0..%d", TCF_LAYER_MAX); |
| } else if (!bstrcmp(a, "mask")) { |
| if (a->next == NULL) |
| return PARSE_ERR(a, "cmp: missing argument"); |
| a = bstr_next(a); |
| |
| mask = bstrtoul(a); |
| if (mask == ULONG_MAX) |
| return PARSE_ERR(a, "cmp: invalid mask"); |
| } else if (!bstrcmp(a, "trans")) { |
| cmp.flags |= TCF_EM_CMP_TRANS; |
| } else if (!bstrcmp(a, "eq") || !bstrcmp(a, "gt") || |
| !bstrcmp(a, "lt")) { |
| |
| 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; |
| |
| if (a->next == NULL) |
| return PARSE_ERR(a, "cmp: missing argument"); |
| a = bstr_next(a); |
| |
| value = bstrtoul(a); |
| if (value == ULONG_MAX) |
| return PARSE_ERR(a, "cmp: invalid value"); |
| |
| value_present = 1; |
| } else |
| return PARSE_ERR(a, "nbyte: unknown parameter"); |
| } |
| |
| if (offset_present == 0 || value_present == 0) |
| return PARSE_ERR(a, "cmp: offset and value required"); |
| |
| cmp.val = (__u32) value; |
| cmp.mask = (__u32) mask; |
| cmp.off = (__u16) offset; |
| cmp.align = (__u8) align; |
| cmp.layer = (__u8) layer; |
| cmp.opnd = (__u8) opnd; |
| |
| addraw_l(n, MAX_MSG, hdr, sizeof(*hdr)); |
| addraw_l(n, MAX_MSG, &cmp, sizeof(cmp)); |
| |
| #undef PARSE_ERR |
| return 0; |
| } |
| |
| static int cmp_print_eopt(FILE *fd, struct tcf_ematch_hdr *hdr, void *data, |
| int data_len) |
| { |
| struct tcf_em_cmp *cmp = data; |
| |
| if (data_len < sizeof(*cmp)) { |
| fprintf(stderr, "CMP header size mismatch\n"); |
| return -1; |
| } |
| |
| if (cmp->align == TCF_EM_ALIGN_U8) |
| fprintf(fd, "u8 "); |
| else if (cmp->align == TCF_EM_ALIGN_U16) |
| fprintf(fd, "u16 "); |
| else if (cmp->align == TCF_EM_ALIGN_U16) |
| fprintf(fd, "u32 "); |
| |
| fprintf(fd, "at %d layer %d ", cmp->off, cmp->layer); |
| |
| if (cmp->mask) |
| fprintf(fd, "mask 0x%x ", cmp->mask); |
| |
| if (cmp->flags & TCF_EM_CMP_TRANS) |
| fprintf(fd, "trans "); |
| |
| if (cmp->opnd == TCF_EM_OPND_EQ) |
| fprintf(fd, "eq "); |
| else if (cmp->opnd == TCF_EM_OPND_LT) |
| fprintf(fd, "lt "); |
| else if (cmp->opnd == TCF_EM_OPND_GT) |
| fprintf(fd, "gt "); |
| |
| fprintf(fd, "%d", cmp->val); |
| |
| return 0; |
| } |
| |
| struct ematch_util cmp_ematch_util = { |
| .kind = "cmp", |
| .kind_num = TCF_EM_CMP, |
| .parse_eopt = cmp_parse_eopt, |
| .print_eopt = cmp_print_eopt, |
| .print_usage = cmp_print_usage |
| }; |