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-rw-r--r--tc/m_ematch.c569
1 files changed, 569 insertions, 0 deletions
diff --git a/tc/m_ematch.c b/tc/m_ematch.c
new file mode 100644
index 0000000..8840a0d
--- /dev/null
+++ b/tc/m_ematch.c
@@ -0,0 +1,569 @@
+/*
+ * m_ematch.c Extended Matches
+ *
+ * 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 <fcntl.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <string.h>
+#include <dlfcn.h>
+#include <stdarg.h>
+#include <errno.h>
+
+#include "utils.h"
+#include "tc_util.h"
+#include "m_ematch.h"
+
+#define EMATCH_MAP "/etc/iproute2/ematch_map"
+
+static struct ematch_util *ematch_list;
+
+/* export to bison parser */
+int ematch_argc;
+char **ematch_argv;
+char *ematch_err;
+struct ematch *ematch_root;
+
+static int begin_argc;
+static char **begin_argv;
+
+static void bstr_print(FILE *fd, const struct bstr *b, int ascii);
+
+static inline void map_warning(int num, char *kind)
+{
+ fprintf(stderr,
+ "Error: Unable to find ematch \"%s\" in %s\n" \
+ "Please assign a unique ID to the ematch kind the suggested " \
+ "entry is:\n" \
+ "\t%d\t%s\n",
+ kind, EMATCH_MAP, num, kind);
+}
+
+static int lookup_map(__u16 num, char *dst, int len, const char *file)
+{
+ int err = -EINVAL;
+ char buf[512];
+ FILE *fd = fopen(file, "r");
+
+ if (fd == NULL)
+ return -errno;
+
+ while (fgets(buf, sizeof(buf), fd)) {
+ char namebuf[512], *p = buf;
+ int id;
+
+ while (*p == ' ' || *p == '\t')
+ p++;
+ if (*p == '#' || *p == '\n' || *p == 0)
+ continue;
+
+ if (sscanf(p, "%d %s", &id, namebuf) != 2) {
+ fprintf(stderr, "ematch map %s corrupted at %s\n",
+ file, p);
+ goto out;
+ }
+
+ if (id == num) {
+ if (dst)
+ strncpy(dst, namebuf, len - 1);
+ err = 0;
+ goto out;
+ }
+ }
+
+ err = -ENOENT;
+out:
+ fclose(fd);
+ return err;
+}
+
+static int lookup_map_id(char *kind, int *dst, const char *file)
+{
+ int err = -EINVAL;
+ char buf[512];
+ FILE *fd = fopen(file, "r");
+
+ if (fd == NULL)
+ return -errno;
+
+ while (fgets(buf, sizeof(buf), fd)) {
+ char namebuf[512], *p = buf;
+ int id;
+
+ while (*p == ' ' || *p == '\t')
+ p++;
+ if (*p == '#' || *p == '\n' || *p == 0)
+ continue;
+
+ if (sscanf(p, "%d %s", &id, namebuf) != 2) {
+ fprintf(stderr, "ematch map %s corrupted at %s\n",
+ file, p);
+ goto out;
+ }
+
+ if (!strcasecmp(namebuf, kind)) {
+ if (dst)
+ *dst = id;
+ err = 0;
+ goto out;
+ }
+ }
+
+ err = -ENOENT;
+ *dst = 0;
+out:
+ fclose(fd);
+ return err;
+}
+
+static struct ematch_util *get_ematch_kind(char *kind)
+{
+ static void *body;
+ void *dlh;
+ char buf[256];
+ struct ematch_util *e;
+
+ for (e = ematch_list; e; e = e->next) {
+ if (strcmp(e->kind, kind) == 0)
+ return e;
+ }
+
+ snprintf(buf, sizeof(buf), "em_%s.so", kind);
+ dlh = dlopen(buf, RTLD_LAZY);
+ if (dlh == NULL) {
+ dlh = body;
+ if (dlh == NULL) {
+ dlh = body = dlopen(NULL, RTLD_LAZY);
+ if (dlh == NULL)
+ return NULL;
+ }
+ }
+
+ snprintf(buf, sizeof(buf), "%s_ematch_util", kind);
+ e = dlsym(dlh, buf);
+ if (e == NULL)
+ return NULL;
+
+ e->next = ematch_list;
+ ematch_list = e;
+
+ return e;
+}
+
+static struct ematch_util *get_ematch_kind_num(__u16 kind)
+{
+ char name[513];
+
+ if (lookup_map(kind, name, sizeof(name), EMATCH_MAP) < 0)
+ return NULL;
+
+ return get_ematch_kind(name);
+}
+
+static int em_parse_call(struct nlmsghdr *n, struct tcf_ematch_hdr *hdr,
+ struct ematch_util *e, struct ematch *t)
+{
+ if (e->parse_eopt_argv) {
+ int argc = 0, i = 0, ret;
+ struct bstr *args;
+ char **argv;
+
+ for (args = t->args; args; args = bstr_next(args))
+ argc++;
+ argv = calloc(argc, sizeof(char *));
+ if (!argv)
+ return -1;
+ for (args = t->args; args; args = bstr_next(args))
+ argv[i++] = args->data;
+
+ ret = e->parse_eopt_argv(n, hdr, argc, argv);
+
+ free(argv);
+ return ret;
+ }
+
+ return e->parse_eopt(n, hdr, t->args->next);
+}
+
+static int parse_tree(struct nlmsghdr *n, struct ematch *tree)
+{
+ int index = 1;
+ struct ematch *t;
+
+ for (t = tree; t; t = t->next) {
+ struct rtattr *tail;
+ struct tcf_ematch_hdr hdr = { .flags = t->relation };
+
+ if (t->inverted)
+ hdr.flags |= TCF_EM_INVERT;
+
+ tail = addattr_nest(n, MAX_MSG, index++);
+
+ if (t->child) {
+ __u32 r = t->child_ref;
+
+ addraw_l(n, MAX_MSG, &hdr, sizeof(hdr));
+ addraw_l(n, MAX_MSG, &r, sizeof(r));
+ } else {
+ int num = 0, err;
+ char buf[64];
+ struct ematch_util *e;
+
+ if (t->args == NULL)
+ return -1;
+
+ strncpy(buf, (char *) t->args->data, sizeof(buf)-1);
+ e = get_ematch_kind(buf);
+ if (e == NULL) {
+ fprintf(stderr, "Unknown ematch \"%s\"\n",
+ buf);
+ return -1;
+ }
+
+ err = lookup_map_id(buf, &num, EMATCH_MAP);
+ if (err < 0) {
+ if (err == -ENOENT)
+ map_warning(e->kind_num, buf);
+ return err;
+ }
+
+ hdr.kind = num;
+ if (em_parse_call(n, &hdr, e, t) < 0)
+ return -1;
+ }
+
+ addattr_nest_end(n, tail);
+ }
+
+ return 0;
+}
+
+static int flatten_tree(struct ematch *head, struct ematch *tree)
+{
+ int i, count = 0;
+ struct ematch *t;
+
+ for (;;) {
+ count++;
+
+ if (tree->child) {
+ for (t = head; t->next; t = t->next);
+ t->next = tree->child;
+ count += flatten_tree(head, tree->child);
+ }
+
+ if (tree->relation == 0)
+ break;
+
+ tree = tree->next;
+ }
+
+ for (i = 0, t = head; t; t = t->next, i++)
+ t->index = i;
+
+ for (t = head; t; t = t->next)
+ if (t->child)
+ t->child_ref = t->child->index;
+
+ return count;
+}
+
+__attribute__((format(printf, 5, 6)))
+int em_parse_error(int err, struct bstr *args, struct bstr *carg,
+ struct ematch_util *e, char *fmt, ...)
+{
+ va_list a;
+
+ va_start(a, fmt);
+ vfprintf(stderr, fmt, a);
+ va_end(a);
+
+ if (ematch_err)
+ fprintf(stderr, ": %s\n... ", ematch_err);
+ else
+ fprintf(stderr, "\n... ");
+
+ while (ematch_argc < begin_argc) {
+ if (ematch_argc == (begin_argc - 1))
+ fprintf(stderr, ">>%s<< ", *begin_argv);
+ else
+ fprintf(stderr, "%s ", *begin_argv);
+ begin_argv++;
+ begin_argc--;
+ }
+
+ fprintf(stderr, "...\n");
+
+ if (args) {
+ fprintf(stderr, "... %s(", e->kind);
+ while (args) {
+ fprintf(stderr, "%s", args == carg ? ">>" : "");
+ bstr_print(stderr, args, 1);
+ fprintf(stderr, "%s%s", args == carg ? "<<" : "",
+ args->next ? " " : "");
+ args = args->next;
+ }
+ fprintf(stderr, ")...\n");
+
+ }
+
+ if (e == NULL) {
+ fprintf(stderr,
+ "Usage: EXPR\n" \
+ "where: EXPR := TERM [ { and | or } EXPR ]\n" \
+ " TERM := [ not ] { MATCH | '(' EXPR ')' }\n" \
+ " MATCH := module '(' ARGS ')'\n" \
+ " ARGS := ARG1 ARG2 ...\n" \
+ "\n" \
+ "Example: a(x y) and not (b(x) or c(x y z))\n");
+ } else
+ e->print_usage(stderr);
+
+ return -err;
+}
+
+static inline void free_ematch_err(void)
+{
+ if (ematch_err) {
+ free(ematch_err);
+ ematch_err = NULL;
+ }
+}
+
+extern int ematch_parse(void);
+
+int parse_ematch(int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n)
+{
+ begin_argc = ematch_argc = *argc_p;
+ begin_argv = ematch_argv = *argv_p;
+
+ if (ematch_parse()) {
+ int err = em_parse_error(EINVAL, NULL, NULL, NULL,
+ "Parse error");
+ free_ematch_err();
+ return err;
+ }
+
+ free_ematch_err();
+
+ /* undo look ahead by parser */
+ ematch_argc++;
+ ematch_argv--;
+
+ if (ematch_root) {
+ struct rtattr *tail, *tail_list;
+
+ struct tcf_ematch_tree_hdr hdr = {
+ .nmatches = flatten_tree(ematch_root, ematch_root),
+ .progid = TCF_EM_PROG_TC
+ };
+
+ tail = addattr_nest(n, MAX_MSG, tca_id);
+ addattr_l(n, MAX_MSG, TCA_EMATCH_TREE_HDR, &hdr, sizeof(hdr));
+
+ tail_list = addattr_nest(n, MAX_MSG, TCA_EMATCH_TREE_LIST);
+
+ if (parse_tree(n, ematch_root) < 0)
+ return -1;
+
+ addattr_nest_end(n, tail_list);
+ addattr_nest_end(n, tail);
+ }
+
+ *argc_p = ematch_argc;
+ *argv_p = ematch_argv;
+
+ return 0;
+}
+
+static int print_ematch_seq(FILE *fd, struct rtattr **tb, int start,
+ int prefix)
+{
+ int n, i = start;
+ struct tcf_ematch_hdr *hdr;
+ int dlen;
+ void *data;
+
+ for (;;) {
+ if (tb[i] == NULL)
+ return -1;
+
+ dlen = RTA_PAYLOAD(tb[i]) - sizeof(*hdr);
+ data = (void *) RTA_DATA(tb[i]) + sizeof(*hdr);
+
+ if (dlen < 0)
+ return -1;
+
+ hdr = RTA_DATA(tb[i]);
+
+ if (hdr->flags & TCF_EM_INVERT)
+ fprintf(fd, "NOT ");
+
+ if (hdr->kind == 0) {
+ __u32 ref;
+
+ if (dlen < sizeof(__u32))
+ return -1;
+
+ ref = *(__u32 *) data;
+ fprintf(fd, "(\n");
+ for (n = 0; n <= prefix; n++)
+ fprintf(fd, " ");
+ if (print_ematch_seq(fd, tb, ref + 1, prefix + 1) < 0)
+ return -1;
+ for (n = 0; n < prefix; n++)
+ fprintf(fd, " ");
+ fprintf(fd, ") ");
+
+ } else {
+ struct ematch_util *e;
+
+ e = get_ematch_kind_num(hdr->kind);
+ if (e == NULL)
+ fprintf(fd, "[unknown ematch %d]\n",
+ hdr->kind);
+ else {
+ fprintf(fd, "%s(", e->kind);
+ if (e->print_eopt(fd, hdr, data, dlen) < 0)
+ return -1;
+ fprintf(fd, ")\n");
+ }
+ if (hdr->flags & TCF_EM_REL_MASK)
+ for (n = 0; n < prefix; n++)
+ fprintf(fd, " ");
+ }
+
+ switch (hdr->flags & TCF_EM_REL_MASK) {
+ case TCF_EM_REL_AND:
+ fprintf(fd, "AND ");
+ break;
+
+ case TCF_EM_REL_OR:
+ fprintf(fd, "OR ");
+ break;
+
+ default:
+ return 0;
+ }
+
+ i++;
+ }
+
+ return 0;
+}
+
+static int print_ematch_list(FILE *fd, struct tcf_ematch_tree_hdr *hdr,
+ struct rtattr *rta)
+{
+ int err = -1;
+ struct rtattr **tb;
+
+ tb = malloc((hdr->nmatches + 1) * sizeof(struct rtattr *));
+ if (tb == NULL)
+ return -1;
+
+ if (hdr->nmatches > 0) {
+ if (parse_rtattr_nested(tb, hdr->nmatches, rta) < 0)
+ goto errout;
+
+ fprintf(fd, "\n ");
+ if (print_ematch_seq(fd, tb, 1, 1) < 0)
+ goto errout;
+ }
+
+ err = 0;
+errout:
+ free(tb);
+ return err;
+}
+
+int print_ematch(FILE *fd, const struct rtattr *rta)
+{
+ struct rtattr *tb[TCA_EMATCH_TREE_MAX+1];
+ struct tcf_ematch_tree_hdr *hdr;
+
+ if (parse_rtattr_nested(tb, TCA_EMATCH_TREE_MAX, rta) < 0)
+ return -1;
+
+ if (tb[TCA_EMATCH_TREE_HDR] == NULL) {
+ fprintf(stderr, "Missing ematch tree header\n");
+ return -1;
+ }
+
+ if (tb[TCA_EMATCH_TREE_LIST] == NULL) {
+ fprintf(stderr, "Missing ematch tree list\n");
+ return -1;
+ }
+
+ if (RTA_PAYLOAD(tb[TCA_EMATCH_TREE_HDR]) < sizeof(*hdr)) {
+ fprintf(stderr, "Ematch tree header size mismatch\n");
+ return -1;
+ }
+
+ hdr = RTA_DATA(tb[TCA_EMATCH_TREE_HDR]);
+
+ return print_ematch_list(fd, hdr, tb[TCA_EMATCH_TREE_LIST]);
+}
+
+struct bstr *bstr_alloc(const char *text)
+{
+ struct bstr *b = calloc(1, sizeof(*b));
+
+ if (b == NULL)
+ return NULL;
+
+ b->data = strdup(text);
+ if (b->data == NULL) {
+ free(b);
+ return NULL;
+ }
+
+ b->len = strlen(text);
+
+ return b;
+}
+
+unsigned long bstrtoul(const struct bstr *b)
+{
+ char *inv = NULL;
+ unsigned long l;
+ char buf[b->len+1];
+
+ memcpy(buf, b->data, b->len);
+ buf[b->len] = '\0';
+
+ l = strtoul(buf, &inv, 0);
+ if (l == ULONG_MAX || inv == buf)
+ return ULONG_MAX;
+
+ return l;
+}
+
+static void bstr_print(FILE *fd, const struct bstr *b, int ascii)
+{
+ int i;
+ char *s = b->data;
+
+ if (ascii)
+ for (i = 0; i < b->len; i++)
+ fprintf(fd, "%c", isprint(s[i]) ? s[i] : '.');
+ else {
+ for (i = 0; i < b->len; i++)
+ fprintf(fd, "%02x", s[i]);
+ fprintf(fd, "\"");
+ for (i = 0; i < b->len; i++)
+ fprintf(fd, "%c", isprint(s[i]) ? s[i] : '.');
+ fprintf(fd, "\"");
+ }
+}
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