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-rw-r--r--lib/route/pktloc.c168
-rw-r--r--lib/route/pktloc_grammar.l42
-rw-r--r--lib/route/pktloc_syntax.y108
3 files changed, 318 insertions, 0 deletions
diff --git a/lib/route/pktloc.c b/lib/route/pktloc.c
new file mode 100644
index 0000000..f0d0155
--- /dev/null
+++ b/lib/route/pktloc.c
@@ -0,0 +1,168 @@
+/*
+ * lib/route/pktloc.c Packet Location Aliasing
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2 of the License.
+ *
+ * Copyright (c) 2008-2010 Thomas Graf <tgraf@suug.ch>
+ */
+
+/**
+ * @ingroup tc
+ * @defgroup pktloc Packet Location Aliasing
+ * Packet Location Aliasing
+ *
+ * The packet location aliasing interface eases the use of offset definitions
+ * inside packets by allowing them to be referenced by name. Known positions
+ * of protocol fields are stored in a configuration file and associated with
+ * a name for later reference. The configuration file is distributed with the
+ * library and provides a well defined set of definitions for most common
+ * protocol fields.
+ *
+ * @subsection pktloc_examples Examples
+ * @par Example 1.1 Looking up a packet location
+ * @code
+ * struct rtnl_pktloc *loc;
+ *
+ * rtnl_pktloc_lookup("ip.src", &loc);
+ * @endcode
+ * @{
+ */
+
+#include <netlink-local.h>
+#include <netlink-tc.h>
+#include <netlink/netlink.h>
+#include <netlink/utils.h>
+#include <netlink/route/pktloc.h>
+
+#include "pktloc_syntax.h"
+#include "pktloc_grammar.h"
+
+/** @cond */
+#define PKTLOC_NAME_HT_SIZ 256
+
+static struct nl_list_head pktloc_name_ht[PKTLOC_NAME_HT_SIZ];
+
+/* djb2 */
+unsigned int pktloc_hash(const char *str)
+{
+ unsigned long hash = 5381;
+ int c;
+
+ while ((c = *str++))
+ hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
+
+ return hash % PKTLOC_NAME_HT_SIZ;
+}
+
+
+void rtnl_pktloc_add(struct rtnl_pktloc *loc)
+{
+ nl_list_add_tail(&loc->list, &pktloc_name_ht[pktloc_hash(loc->name)]);
+}
+
+extern int pktloc_parse(void *scanner);
+
+/** @endcond */
+
+static void rtnl_pktloc_free(struct rtnl_pktloc *loc)
+{
+ if (!loc)
+ return;
+
+ free(loc->name);
+ free(loc);
+}
+
+static int read_pktlocs(void)
+{
+ YY_BUFFER_STATE buf;
+ yyscan_t scanner = NULL;
+ static time_t last_read;
+ struct stat st = {0};
+ char *path;
+ int i, err;
+ FILE *fd;
+
+ asprintf(&path, "%s/pktloc", SYSCONFDIR);
+
+ /* if stat fails, just try to read the file */
+ if (stat(path, &st) == 0) {
+ /* Don't re-read file if file is unchanged */
+ if (last_read == st.st_mtime)
+ return 0;
+ }
+
+ if (!(fd = fopen(path, "r")))
+ return -NLE_PKTLOC_FILE;
+
+ for (i = 0; i < PKTLOC_NAME_HT_SIZ; i++) {
+ struct rtnl_pktloc *loc, *n;
+
+ nl_list_for_each_entry_safe(loc, n, &pktloc_name_ht[i], list)
+ rtnl_pktloc_free(loc);
+
+ nl_init_list_head(&pktloc_name_ht[i]);
+ }
+
+ if ((err = pktloc_lex_init(&scanner)) < 0)
+ return -NLE_FAILURE;
+
+ buf = pktloc__create_buffer(fd, YY_BUF_SIZE, scanner);
+ pktloc__switch_to_buffer(buf, scanner);
+
+ if ((err = pktloc_parse(scanner)) < 0)
+ return -NLE_FAILURE;
+
+ if (scanner)
+ pktloc_lex_destroy(scanner);
+
+ free(path);
+ last_read = st.st_mtime;
+
+ return 0;
+}
+
+/**
+ * Lookup packet location alias
+ * @arg name Name of packet location.
+ *
+ * Tries to find a matching packet location alias for the supplied
+ * packet location name.
+ *
+ * The file containing the packet location definitions is automatically
+ * re-read if its modification time has changed since the last call.
+ *
+ * @return 0 on success or a negative error code.
+ * @retval NLE_PKTLOC_FILE Unable to open packet location file.
+ * @retval NLE_OBJ_NOTFOUND No matching packet location alias found.
+ */
+int rtnl_pktloc_lookup(const char *name, struct rtnl_pktloc **result)
+{
+ struct rtnl_pktloc *loc;
+ int hash, err;
+
+ if ((err = read_pktlocs()) < 0)
+ return err;
+
+ hash = pktloc_hash(name);
+ nl_list_for_each_entry(loc, &pktloc_name_ht[hash], list) {
+ if (!strcasecmp(loc->name, name)) {
+ *result = loc;
+ return 0;
+ }
+ }
+
+ return -NLE_OBJ_NOTFOUND;
+}
+
+static int __init pktloc_init(void)
+{
+ int i;
+
+ for (i = 0; i < PKTLOC_NAME_HT_SIZ; i++)
+ nl_init_list_head(&pktloc_name_ht[i]);
+
+ return 0;
+}
diff --git a/lib/route/pktloc_grammar.l b/lib/route/pktloc_grammar.l
new file mode 100644
index 0000000..f710430
--- /dev/null
+++ b/lib/route/pktloc_grammar.l
@@ -0,0 +1,42 @@
+%{
+ #include <netlink-local.h>
+ #include <netlink-tc.h>
+ #include <netlink/netlink.h>
+ #include <netlink/utils.h>
+ #include <netlink/route/pktloc.h>
+ #include "pktloc_syntax.h"
+%}
+
+%option 8bit
+%option reentrant
+%option warn
+%option noyywrap
+%option nounput
+%option bison-bridge
+%option bison-locations
+%option prefix="pktloc_"
+
+%%
+
+[ \t\r\n]+
+
+"#".*
+
+[[:digit:]]+ |
+0[xX][[:xdigit:]]+ {
+ yylval->i = strtoul(yytext, NULL, 0);
+ return NUMBER;
+ }
+
+"+" { return yylval->i = yytext[0]; }
+
+[lL][iI][nN][kK] { yylval->i = TCF_LAYER_LINK; return LAYER; }
+[nN][eE][tT] { yylval->i = TCF_LAYER_NETWORK; return LAYER; }
+[tT][cC][pP] { yylval->i = TCF_LAYER_TRANSPORT; return LAYER; }
+
+[^ \t\r\n+]+ {
+ yylval->s = strdup(yytext);
+ if (yylval->s == NULL)
+ return ERROR;
+ return NAME;
+ }
diff --git a/lib/route/pktloc_syntax.y b/lib/route/pktloc_syntax.y
new file mode 100644
index 0000000..05d609a
--- /dev/null
+++ b/lib/route/pktloc_syntax.y
@@ -0,0 +1,108 @@
+%{
+#include <netlink-local.h>
+#include <netlink-tc.h>
+#include <netlink/netlink.h>
+#include <netlink/utils.h>
+#include <netlink/route/pktloc.h>
+%}
+
+%locations
+%error-verbose
+%define api.pure
+%name-prefix "pktloc_"
+
+%parse-param {void *scanner}
+%lex-param {void *scanner}
+
+%union {
+ struct rtnl_pktloc *l;
+ uint32_t i;
+ char *s;
+}
+
+%{
+extern int pktloc_lex(YYSTYPE *, YYLTYPE *, void *);
+extern void rtnl_pktloc_add(struct rtnl_pktloc *);
+
+static void yyerror(YYLTYPE *locp, void *scanner, const char *msg)
+{
+ /* FIXME */
+}
+%}
+
+%token <i> ERROR NUMBER LAYER
+%token <s> NAME
+
+%type <i> mask layer
+%type <l> location
+
+%destructor { free($$); } NAME
+
+%start input
+
+%%
+
+input:
+ def
+ { }
+ ;
+
+def:
+ /* empty */
+ { }
+ | location def
+ { }
+ ;
+
+location:
+ NAME NAME layer NUMBER mask
+ {
+ struct rtnl_pktloc *loc;
+
+ if (!(loc = calloc(1, sizeof(*loc)))) {
+ /* FIXME */
+ }
+
+ if (!strcasecmp($2, "u8"))
+ loc->align = TCF_EM_ALIGN_U8;
+ else if (!strcasecmp($2, "h8")) {
+ loc->align = TCF_EM_ALIGN_U8;
+ loc->flags = TCF_EM_CMP_TRANS;
+ } else if (!strcasecmp($2, "u16"))
+ loc->align = TCF_EM_ALIGN_U16;
+ else if (!strcasecmp($2, "h16")) {
+ loc->align = TCF_EM_ALIGN_U16;
+ loc->flags = TCF_EM_CMP_TRANS;
+ } else if (!strcasecmp($2, "u32"))
+ loc->align = TCF_EM_ALIGN_U32;
+ else if (!strcasecmp($2, "h32")) {
+ loc->align = TCF_EM_ALIGN_U32;
+ loc->flags = TCF_EM_CMP_TRANS;
+ }
+
+ free($2);
+
+ loc->name = $1;
+ loc->layer = $3;
+ loc->offset = $4;
+ loc->mask = $5;
+
+ rtnl_pktloc_add(loc);
+
+ $$ = loc;
+ }
+ ;
+
+layer:
+ /* empty */
+ { $$ = TCF_LAYER_NETWORK; }
+ | LAYER '+'
+ { $$ = $1; }
+ ;
+
+mask:
+ /* empty */
+ { $$ = 0; }
+ | NUMBER
+ { $$ = $1; }
+ ;