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author | Thomas Graf <tgr@lsx.(none)> | 2010-07-02 12:06:59 (GMT) |
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committer | Thomas Graf <tgr@lsx.(none)> | 2010-07-02 12:06:59 (GMT) |
commit | db5bd57899affbcaf42ac0b93c5c7be8f51ca390 (patch) | |
tree | ca9e9cc76aad8662a7ac4005f7807ae6d476e3c7 /lib | |
parent | d378220c96c3c8b6f27dca33e7d8ba03318f9c2d (diff) | |
download | libnl-db5bd57899affbcaf42ac0b93c5c7be8f51ca390.zip libnl-db5bd57899affbcaf42ac0b93c5c7be8f51ca390.tar.gz libnl-db5bd57899affbcaf42ac0b93c5c7be8f51ca390.tar.bz2 |
Packet Location Interface
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Makefile.am | 19 | ||||
-rw-r--r-- | lib/error.c | 1 | ||||
-rw-r--r-- | lib/route/pktloc.c | 168 | ||||
-rw-r--r-- | lib/route/pktloc_grammar.l | 42 | ||||
-rw-r--r-- | lib/route/pktloc_syntax.y | 108 |
5 files changed, 336 insertions, 2 deletions
diff --git a/lib/Makefile.am b/lib/Makefile.am index 1c2ae99..082408c 100644 --- a/lib/Makefile.am +++ b/lib/Makefile.am @@ -1,6 +1,6 @@ # -*- Makefile -*- -AM_CFLAGS = -Wall -I${top_srcdir}/include -D_GNU_SOURCE +AM_CFLAGS = -Wall -I${top_srcdir}/include -D_GNU_SOURCE -DSYSCONFDIR=\"$(sysconfdir)/libnl\" lib_LTLIBRARIES = \ libnl.la libnl-genl.la libnl-route.la libnl-nf.la @@ -23,6 +23,19 @@ libnl_nf_la_SOURCES = \ netfilter/netfilter.c netfilter/nfnl.c netfilter/queue.c \ netfilter/queue_msg.c netfilter/queue_msg_obj.c netfilter/queue_obj.c +BUILT_SOURCES = route/pktloc_syntax.h +CLEANFILES = \ + route/pktloc_grammar.c route/pktloc_grammar.h \ + route/pktloc_syntax.c route/pktloc_syntax.h + +# Hack to avoid using ylwrap. It does not function correctly in combination +# with --header-file= +route/pktloc_grammar.c: route/pktloc_grammar.l + $(LEX) --header-file=route/pktloc_grammar.h $(LFLAGS) -o $@ $^ + +route/pktloc_syntax.c: route/pktloc_syntax.y + $(YACC) -d $(YFLAGS) -o $@ $^ + libnl_route_la_LDFLAGS = -version-info 2:0:0 libnl_route_la_LIBADD = libnl.la libnl_route_la_SOURCES = \ @@ -40,4 +53,6 @@ libnl_route_la_SOURCES = \ route/sch/fifo.c route/sch/htb.c route/sch/netem.c route/sch/prio.c \ route/sch/red.c route/sch/sfq.c route/sch/tbf.c \ \ - fib_lookup/lookup.c fib_lookup/request.c + fib_lookup/lookup.c fib_lookup/request.c \ + \ + route/pktloc_syntax.c route/pktloc_grammar.c route/pktloc.c diff --git a/lib/error.c b/lib/error.c index b94a235..9a9fac7 100644 --- a/lib/error.c +++ b/lib/error.c @@ -42,6 +42,7 @@ static const char *errmsg[NLE_MAX+1] = { [NLE_PROTO_MISMATCH] = "Protocol mismatch", [NLE_NOACCESS] = "No Access", [NLE_PERM] = "Operation not permitted", +[NLE_PKTLOC_FILE] = "Unable to open packet location file", }; /** 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; } + ; |