tc: add cls_bpf frontend

This is the iproute2 part of the kernel patch "net: sched:
add BPF-based traffic classifier".

[Will re-submit later again for iproute2 when window for
 -next submissions opens.]

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Thomas Graf <tgraf@suug.ch>

diff --git a/tc/Makefile b/tc/Makefile
index f54a955b046d81810aa0be4b850da050313c79a8..84215c06af3888df0c2ed12449f25ed80b6320fb 100644 (file)
--- a/tc/Makefile
+++ b/tc/Makefile
@@ -22,6 +22,7 @@ TCMODULES += f_u32.o
 TCMODULES += f_route.o
 TCMODULES += f_fw.o
 TCMODULES += f_basic.o
+TCMODULES += f_bpf.o
 TCMODULES += f_flow.o
 TCMODULES += f_cgroup.o
 TCMODULES += q_dsmark.o

diff --git a/tc/f_bpf.c b/tc/f_bpf.c
new file mode 100644 (file)
index 0000000..d52d7d8
--- /dev/null
+++ b/tc/f_bpf.c
@@ -0,0 +1,288 @@
+/*
+ * f_bpf.c     BPF-based Classifier
+ *
+ *             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:    Daniel Borkmann <dborkman@redhat.com>
+ */
+
+#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 <stdbool.h>
+#include <errno.h>
+#include <linux/filter.h>
+#include <linux/if.h>
+
+#include "utils.h"
+#include "tc_util.h"
+
+static void explain(void)
+{
+       fprintf(stderr, "Usage: ... bpf ...\n");
+       fprintf(stderr, "\n");
+       fprintf(stderr, " [inline]:     run bytecode BPF_BYTECODE\n");
+       fprintf(stderr, " [from file]:  run bytecode-file FILE\n");
+       fprintf(stderr, "\n");
+       fprintf(stderr, "               [ police POLICE_SPEC ] [ action ACTION_SPEC ]\n");
+       fprintf(stderr, "               [ classid CLASSID ]\n");
+       fprintf(stderr, "\n");
+       fprintf(stderr, "Where BPF_BYTECODE := \'s,c t f k,c t f k,c t f k,...\'\n");
+       fprintf(stderr, "      c,t,f,k and s are decimals; s denotes number of 4-tuples\n");
+       fprintf(stderr, "Where FILE points to a file containing the BPF_BYTECODE string\n");
+       fprintf(stderr, "\nNOTE: CLASSID is parsed as hexadecimal input.\n");
+}
+
+static int bpf_parse_string(char *arg, bool from_file, __u16 *bpf_len,
+                           char **bpf_string, bool *need_release,
+                           const char separator)
+{
+       char sp;
+
+       if (from_file) {
+               size_t tmp_len, op_len = sizeof("65535 255 255 4294967295,");
+               char *tmp_string;
+               FILE *fp;
+
+               tmp_len = sizeof("4096,") + BPF_MAXINSNS * op_len;
+               tmp_string = malloc(tmp_len);
+               if (tmp_string == NULL)
+                       return -ENOMEM;
+
+               memset(tmp_string, 0, tmp_len);
+
+               fp = fopen(arg, "r");
+               if (fp == NULL) {
+                       perror("Cannot fopen");
+                       free(tmp_string);
+                       return -ENOENT;
+               }
+
+               if (!fgets(tmp_string, tmp_len, fp)) {
+                       free(tmp_string);
+                       fclose(fp);
+                       return -EIO;
+               }
+
+               fclose(fp);
+
+               *need_release = true;
+               *bpf_string = tmp_string;
+       } else {
+               *need_release = false;
+               *bpf_string = arg;
+       }
+
+       if (sscanf(*bpf_string, "%hu%c", bpf_len, &sp) != 2 ||
+           sp != separator) {
+               if (*need_release)
+                       free(*bpf_string);
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int bpf_parse_ops(int argc, char **argv, struct nlmsghdr *n,
+                        bool from_file)
+{
+       char *bpf_string, *token, separator = ',';
+       struct sock_filter bpf_ops[BPF_MAXINSNS];
+       int ret = 0, i = 0;
+       bool need_release;
+       __u16 bpf_len = 0;
+
+       if (argc < 1)
+               return -EINVAL;
+       if (bpf_parse_string(argv[0], from_file, &bpf_len, &bpf_string,
+                            &need_release, separator))
+               return -EINVAL;
+       if (bpf_len == 0 || bpf_len > BPF_MAXINSNS) {
+               ret = -EINVAL;
+               goto out;
+       }
+
+       token = bpf_string;
+       while ((token = strchr(token, separator)) && (++token)[0]) {
+               if (i >= bpf_len) {
+                       fprintf(stderr, "Real program length exceeds encoded "
+                               "length parameter!\n");
+                       ret = -EINVAL;
+                       goto out;
+               }
+
+               if (sscanf(token, "%hu %hhu %hhu %u,",
+                          &bpf_ops[i].code, &bpf_ops[i].jt,
+                          &bpf_ops[i].jf, &bpf_ops[i].k) != 4) {
+                       fprintf(stderr, "Error at instruction %d!\n", i);
+                       ret = -EINVAL;
+                       goto out;
+               }
+
+               i++;
+       }
+
+       if (i != bpf_len) {
+               fprintf(stderr, "Parsed program length is less than encoded"
+                       "length parameter!\n");
+               ret = -EINVAL;
+               goto out;
+       }
+
+       addattr_l(n, MAX_MSG, TCA_BPF_OPS_LEN, &bpf_len, sizeof(bpf_len));
+       addattr_l(n, MAX_MSG, TCA_BPF_OPS, &bpf_ops,
+                 bpf_len * sizeof(struct sock_filter));
+out:
+       if (need_release)
+               free(bpf_string);
+
+       return ret;
+}
+
+static void bpf_print_ops(FILE *f, struct rtattr *bpf_ops, __u16 len)
+{
+       struct sock_filter *ops = (struct sock_filter *) RTA_DATA(bpf_ops);
+       int i;
+
+       if (len == 0)
+               return;
+
+       fprintf(f, "bytecode \'%u,", len);
+
+       for (i = 0; i < len - 1; i++)
+               fprintf(f, "%hu %hhu %hhu %u,", ops[i].code, ops[i].jt,
+                       ops[i].jf, ops[i].k);
+
+       fprintf(f, "%hu %hhu %hhu %u\'\n", ops[i].code, ops[i].jt,
+               ops[i].jf, ops[i].k);
+}
+
+static int bpf_parse_opt(struct filter_util *qu, char *handle,
+                        int argc, char **argv, struct nlmsghdr *n)
+{
+       struct tcmsg *t = NLMSG_DATA(n);
+       struct rtattr *tail;
+       long h = 0;
+
+       if (argc == 0)
+               return 0;
+
+       if (handle) {
+               h = strtol(handle, NULL, 0);
+               if (h == LONG_MIN || h == LONG_MAX) {
+                       fprintf(stderr, "Illegal handle \"%s\", must be "
+                               "numeric.\n", handle);
+                       return -1;
+               }
+       }
+
+       t->tcm_handle = h;
+
+       tail = (struct rtattr*)(((void*)n)+NLMSG_ALIGN(n->nlmsg_len));
+       addattr_l(n, MAX_MSG, TCA_OPTIONS, NULL, 0);
+
+       while (argc > 0) {
+               if (matches(*argv, "run") == 0) {
+                       bool from_file;
+                       NEXT_ARG();
+                       if (strcmp(*argv, "bytecode-file") == 0) {
+                               from_file = true;
+                       } else if (strcmp(*argv, "bytecode") == 0) {
+                               from_file = false;
+                       } else {
+                               fprintf(stderr, "What is \"%s\"?\n", *argv);
+                               explain();
+                               return -1;
+                       }
+                       NEXT_ARG();
+                       if (bpf_parse_ops(argc, argv, n, from_file)) {
+                               fprintf(stderr, "Illegal \"bytecode\"\n");
+                               return -1;
+                       }
+               } else if (matches(*argv, "classid") == 0 ||
+                          strcmp(*argv, "flowid") == 0) {
+                       unsigned handle;
+                       NEXT_ARG();
+                       if (get_tc_classid(&handle, *argv)) {
+                               fprintf(stderr, "Illegal \"classid\"\n");
+                               return -1;
+                       }
+                       addattr_l(n, MAX_MSG, TCA_BPF_CLASSID, &handle, 4);
+               } else if (matches(*argv, "action") == 0) {
+                       NEXT_ARG();
+                       if (parse_action(&argc, &argv, TCA_BPF_ACT, n)) {
+                               fprintf(stderr, "Illegal \"action\"\n");
+                               return -1;
+                       }
+                       continue;
+               } else if (matches(*argv, "police") == 0) {
+                       NEXT_ARG();
+                       if (parse_police(&argc, &argv, TCA_BPF_POLICE, n)) {
+                               fprintf(stderr, "Illegal \"police\"\n");
+                               return -1;
+                       }
+                       continue;
+               } else if (strcmp(*argv, "help") == 0) {
+                       explain();
+                       return -1;
+               } else {
+                       fprintf(stderr, "What is \"%s\"?\n", *argv);
+                       explain();
+                       return -1;
+               }
+               argc--; argv++;
+       }
+
+       tail->rta_len = (((void*)n)+n->nlmsg_len) - (void*)tail;
+       return 0;
+}
+
+static int bpf_print_opt(struct filter_util *qu, FILE *f,
+                        struct rtattr *opt, __u32 handle)
+{
+       struct rtattr *tb[TCA_BPF_MAX + 1];
+
+       if (opt == NULL)
+               return 0;
+
+       parse_rtattr_nested(tb, TCA_BPF_MAX, opt);
+
+       if (handle)
+               fprintf(f, "handle 0x%x ", handle);
+
+       if (tb[TCA_BPF_CLASSID]) {
+               SPRINT_BUF(b1);
+               fprintf(f, "flowid %s ",
+                       sprint_tc_classid(rta_getattr_u32(tb[TCA_BPF_CLASSID]), b1));
+       }
+
+       if (tb[TCA_BPF_OPS] && tb[TCA_BPF_OPS_LEN])
+               bpf_print_ops(f, tb[TCA_BPF_OPS],
+                             rta_getattr_u16(tb[TCA_BPF_OPS_LEN]));
+
+       if (tb[TCA_BPF_POLICE]) {
+               fprintf(f, "\n");
+               tc_print_police(f, tb[TCA_BPF_POLICE]);
+       }
+
+       if (tb[TCA_BPF_ACT]) {
+               tc_print_action(f, tb[TCA_BPF_ACT]);
+       }
+
+       return 0;
+}
+
+struct filter_util bpf_filter_util = {
+       .id = "bpf",
+       .parse_fopt = bpf_parse_opt,
+       .print_fopt = bpf_print_opt,
+};