├── .gitignore ├── LICENSE ├── Makefile ├── README.md ├── examples ├── dump-table-raw │ └── dump-table-raw.go ├── dump-table-rules │ └── dump-table-rules.go └── lock │ └── lock.go ├── libip4tc ├── libip4tc.go └── libip4tc_test.go ├── libip6tc ├── libip6tc.go └── libip6tc_test.go ├── libiptc.go ├── update-version.sh ├── xtables-lock.c └── xtables-lock.h /.gitignore: -------------------------------------------------------------------------------- 1 | examples/dump-table-raw/dump-table-raw 2 | examples/dump-table-rules/dump-table-rules 3 | examples/lock/lock 4 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 2, June 1991 3 | 4 | Copyright (C) 1989, 1991 Free Software Foundation, Inc., 5 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 6 | Everyone is permitted to copy and distribute verbatim copies 7 | of this license document, but changing it is not allowed. 8 | 9 | Preamble 10 | 11 | The licenses for most software are designed to take away your 12 | freedom to share and change it. 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It is safest 289 | to attach them to the start of each source file to most effectively 290 | convey the exclusion of warranty; and each file should have at least 291 | the "copyright" line and a pointer to where the full notice is found. 292 | 293 | {description} 294 | Copyright (C) {year} {fullname} 295 | 296 | This program is free software; you can redistribute it and/or modify 297 | it under the terms of the GNU General Public License as published by 298 | the Free Software Foundation; either version 2 of the License, or 299 | (at your option) any later version. 300 | 301 | This program is distributed in the hope that it will be useful, 302 | but WITHOUT ANY WARRANTY; without even the implied warranty of 303 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 304 | GNU General Public License for more details. 305 | 306 | You should have received a copy of the GNU General Public License along 307 | with this program; if not, write to the Free Software Foundation, Inc., 308 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 309 | 310 | Also add information on how to contact you by electronic and paper mail. 311 | 312 | If the program is interactive, make it output a short notice like this 313 | when it starts in an interactive mode: 314 | 315 | Gnomovision version 69, Copyright (C) year name of author 316 | Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 317 | This is free software, and you are welcome to redistribute it 318 | under certain conditions; type `show c' for details. 319 | 320 | The hypothetical commands `show w' and `show c' should show the appropriate 321 | parts of the General Public License. Of course, the commands you use may 322 | be called something other than `show w' and `show c'; they could even be 323 | mouse-clicks or menu items--whatever suits your program. 324 | 325 | You should also get your employer (if you work as a programmer) or your 326 | school, if any, to sign a "copyright disclaimer" for the program, if 327 | necessary. Here is a sample; alter the names: 328 | 329 | Yoyodyne, Inc., hereby disclaims all copyright interest in the program 330 | `Gnomovision' (which makes passes at compilers) written by James Hacker. 331 | 332 | {signature of Ty Coon}, 1 April 1989 333 | Ty Coon, President of Vice 334 | 335 | This General Public License does not permit incorporating your program into 336 | proprietary programs. If your program is a subroutine library, you may 337 | consider it more useful to permit linking proprietary applications with the 338 | library. If this is what you want to do, use the GNU Lesser General 339 | Public License instead of this License. 340 | 341 | -------------------------------------------------------------------------------- /Makefile: -------------------------------------------------------------------------------- 1 | SRCFILES := *.go libip4tc/*.go libip6tc/*.go 2 | 3 | all: build examples 4 | 5 | build: 6 | go build 7 | cd libip4tc && go build 8 | cd libip6tc && go build 9 | 10 | test: 11 | go test 12 | 13 | examples: examples/dump-table-raw/dump-table-raw examples/dump-table-rules/dump-table-rules examples/lock/lock 14 | 15 | examples/dump-table-raw/dump-table-raw: examples/dump-table-raw/dump-table-raw.go $(SRCFILES) 16 | cd examples/dump-table-raw && go build 17 | 18 | examples/dump-table-rules/dump-table-rules: examples/dump-table-rules/dump-table-rules.go $(SRCFILES) 19 | cd examples/dump-table-rules && go build 20 | 21 | examples/lock/lock: examples/lock/lock.go $(SRCFILES) 22 | cd examples/lock && go build 23 | 24 | clean: 25 | rm -f examples/dump-table-raw/dump-table-raw examples/dump-table-rules/dump-table-rules examples/lock/lock 26 | 27 | .PHONY: all build test examples clean 28 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # libiptc Go bindings 2 | 3 | [libiptc](http://www.tldp.org/HOWTO/Querying-libiptc-HOWTO/whatis.html) bindings for Go language. 4 | Object-oriented design, support for IPv6 (libip6tc) and same wait locking mechanism as iptables/ip6tables official binaries. 5 | 6 | This project currently contains Go bindings to libip4tc/libip6tc dynamic link libraries, most headers/commenst are from original [iptables](http://www.netfilter.org/) C headers. 7 | 8 | Please note that there is no public/stable C/C++ API for libiptc, quoting from official [Netfilter FAQs](http://www.netfilter.org/documentation/FAQ/netfilter-faq-4.html#ss4.5): 9 | 10 | > 4.5 Is there an C/C++ API for adding/removing rules? 11 | > 12 | > The answer unfortunately is: No. 13 | > 14 | > Now you might think 'but what about libiptc?'. As has been pointed out numerous times on the mailinglist(s), libiptc was _NEVER_ meant to be used as a public interface. We don't guarantee a stable interface, and it is planned to remove it in the next incarnation of linux packet filtering. libiptc is way too low-layer to be used reasonably anyway. 15 | > 16 | > We are well aware that there is a fundamental lack for such an API, and we are working on improving that situation. Until then, it is recommended to either use system() or open a pipe into stdin of iptables-restore. The latter will give you a way better performance. 17 | > 18 | 19 | # How to use 20 | 21 | Install the dependency with `go get` or your dependency system of choice. 22 | ``` 23 | go get github.com/gdm85/go-libiptc 24 | ``` 25 | 26 | You can use xtables locking features by importing `github.com/gdm85/go-libiptc` and IPv4/IPv6 features by importing either `github.com/gdm85/go-libiptc/ipv4` or `github.com/gdm85/go-libiptc/ipv6`. 27 | 28 | Once the package is imported and being used, the OS thread is locked to a specific background goroutine and all calls are performed serially through such goroutine. 29 | 30 | # Building 31 | 32 | In order to build this package it is necessary for it to reside within a proper GOPATH and that iptables headers are globally available on the system; on Debian/Ubuntu systems these are provided by `iptables-dev` package, otherwise you can refer to the official upstream iptables git repository: `git://git.netfilter.org/iptables.git`. 33 | 34 | To build everything (except tests): 35 | ``` 36 | make 37 | ``` 38 | 39 | To build the package it will suffice a: 40 | ``` 41 | make build 42 | ``` 43 | 44 | To run tests (with proper root privileges): 45 | ``` 46 | make test 47 | ``` 48 | 49 | To build the examples: 50 | ``` 51 | make examples 52 | ``` 53 | 54 | # TODO 55 | 56 | * ~~separate libip6tc package that uses '#cgo LDFLAGS: -lip6tc'~~ 57 | * unit tests coverage 58 | * finally, some analysis of memory leakage 59 | 60 | # Useful resources 61 | 62 | * http://www.bani.com.br/2012/05/programmatically-managing-iptables-rules-in-c-iptc/ 63 | 64 | # License 65 | 66 | Licensed under [GNU/GPL v2](LICENSE). 67 | -------------------------------------------------------------------------------- /examples/dump-table-raw/dump-table-raw.go: -------------------------------------------------------------------------------- 1 | /* 2 | * go-libiptc v0.3.1 - libiptc bindings for Go language 3 | * Copyright (C) 2015 gdm85 - https://github.com/gdm85/go-libiptc/ 4 | 5 | This program is free software; you can redistribute it and/or 6 | modify it under the terms of the GNU General Public License 7 | as published by the Free Software Foundation; either version 2 8 | of the License, or (at your option) any later version. 9 | 10 | This program is distributed in the hope that it will be useful, 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 | GNU General Public License for more details. 14 | 15 | You should have received a copy of the GNU General Public License 16 | along with this program; if not, write to the Free Software 17 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 18 | */ 19 | 20 | package main 21 | 22 | import ( 23 | "fmt" 24 | "os" 25 | 26 | common "github.com/gdm85/go-libiptc" 27 | "github.com/gdm85/go-libiptc/libip4tc" 28 | "github.com/gdm85/go-libiptc/libip6tc" 29 | ) 30 | 31 | func showSyntax() { 32 | fmt.Fprintf(os.Stderr, "Usage: dump-table-raw [-4|-6] \n") 33 | os.Exit(1) 34 | } 35 | 36 | func main() { 37 | if len(os.Args) != 3 { 38 | showSyntax() 39 | } 40 | 41 | var useIpv6 bool 42 | switch os.Args[1] { 43 | case `-4`: 44 | case `-6`: 45 | useIpv6 = true 46 | default: 47 | showSyntax() 48 | } 49 | 50 | acquired, err := common.XtablesLock(false, 0) 51 | if err != nil { 52 | panic(err) 53 | } 54 | if !acquired { 55 | fmt.Fprintf(os.Stderr, "dump-table-raw: could not acquire xtables lock!\n") 56 | os.Exit(1) 57 | } 58 | defer func() { 59 | _, err := common.XtablesUnlock() 60 | if err != nil { 61 | panic(err) 62 | } 63 | }() 64 | 65 | tableName := os.Args[2] 66 | 67 | if !useIpv6 { 68 | table, err := libip4tc.TableInit(tableName) 69 | if err != nil { 70 | fmt.Fprintf(os.Stderr, "dump-table-raw: %s\n", err) 71 | os.Exit(3) 72 | } 73 | defer table.Free() 74 | 75 | // use the native/undocumented DumpEntries() anyways 76 | table.DumpEntries() 77 | } else { 78 | table, err := libip6tc.TableInit(tableName) 79 | if err != nil { 80 | fmt.Fprintf(os.Stderr, "dump-table-raw: %s\n", err) 81 | os.Exit(3) 82 | } 83 | defer table.Free() 84 | 85 | // use the native/undocumented DumpEntries() anyways 86 | table.DumpEntries() 87 | } 88 | } 89 | -------------------------------------------------------------------------------- /examples/dump-table-rules/dump-table-rules.go: -------------------------------------------------------------------------------- 1 | /* 2 | * go-libiptc v0.3.1 - libiptc bindings for Go language 3 | * Copyright (C) 2015 gdm85 - https://github.com/gdm85/go-libiptc/ 4 | 5 | This program is free software; you can redistribute it and/or 6 | modify it under the terms of the GNU General Public License 7 | as published by the Free Software Foundation; either version 2 8 | of the License, or (at your option) any later version. 9 | 10 | This program is distributed in the hope that it will be useful, 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 | GNU General Public License for more details. 14 | 15 | You should have received a copy of the GNU General Public License 16 | along with this program; if not, write to the Free Software 17 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 18 | */ 19 | 20 | package main 21 | 22 | import ( 23 | "fmt" 24 | "os" 25 | 26 | common "github.com/gdm85/go-libiptc" 27 | "github.com/gdm85/go-libiptc/libip4tc" 28 | "github.com/gdm85/go-libiptc/libip6tc" 29 | ) 30 | 31 | func showSyntax() { 32 | fmt.Fprintf(os.Stderr, "Usage: dump-table-rules [-4|-6] \n") 33 | os.Exit(1) 34 | } 35 | 36 | func main() { 37 | if len(os.Args) != 3 { 38 | showSyntax() 39 | } 40 | 41 | var useIpv6 bool 42 | switch os.Args[1] { 43 | case `-4`: 44 | case `-6`: 45 | useIpv6 = true 46 | default: 47 | showSyntax() 48 | } 49 | 50 | acquired, err := common.XtablesLock(false, 0) 51 | if err != nil { 52 | panic(err) 53 | } 54 | if !acquired { 55 | fmt.Fprintf(os.Stderr, "dump-table-rules: could not acquire xtables lock!\n") 56 | os.Exit(1) 57 | } 58 | defer func() { 59 | _, err := common.XtablesUnlock() 60 | if err != nil { 61 | panic(err) 62 | } 63 | }() 64 | 65 | tableName := os.Args[2] 66 | 67 | if !useIpv6 { 68 | table, err := libip4tc.TableInit(tableName) 69 | if err != nil { 70 | fmt.Fprintf(os.Stderr, "dump-table-rules: %s\n", err) 71 | os.Exit(3) 72 | } 73 | defer table.Free() 74 | 75 | // traverse trough chains 76 | chain, err := table.FirstChain() 77 | if err != nil { 78 | fmt.Fprintf(os.Stderr, "dump-table-rules: %s\n", err) 79 | os.Exit(3) 80 | } 81 | for chain != "" { 82 | // use Go-native rules conversion 83 | e, err := table.FirstRule(chain) 84 | if err != nil { 85 | fmt.Fprintf(os.Stderr, "dump-table-rules: %s\n", err) 86 | os.Exit(3) 87 | } 88 | for !e.IsEmpty() { 89 | fmt.Println(chain+":", table.IptEntry2Rule(&e).String()) 90 | e, err = table.NextRule(e) 91 | if err != nil { 92 | fmt.Fprintf(os.Stderr, "dump-table-rules: %s\n", err) 93 | os.Exit(3) 94 | } 95 | } 96 | 97 | chain, err = table.NextChain() 98 | if err != nil { 99 | fmt.Fprintf(os.Stderr, "dump-table-rules: %s\n", err) 100 | os.Exit(3) 101 | } 102 | } 103 | } else { 104 | table, err := libip6tc.TableInit(tableName) 105 | if err != nil { 106 | fmt.Fprintf(os.Stderr, "dump-table-rules: %s\n", err) 107 | os.Exit(3) 108 | } 109 | defer table.Free() 110 | 111 | // traverse trough chains 112 | chain, err := table.FirstChain() 113 | if err != nil { 114 | fmt.Fprintf(os.Stderr, "dump-table-rules: %s\n", err) 115 | os.Exit(3) 116 | } 117 | for chain != "" { 118 | // use Go-native rules conversion 119 | e, err := table.FirstRule(chain) 120 | if err != nil { 121 | fmt.Fprintf(os.Stderr, "dump-table-rules: %s\n", err) 122 | os.Exit(3) 123 | } 124 | for !e.IsEmpty() { 125 | fmt.Println(chain+":", table.IptEntry2Rule(&e).String()) 126 | e, err = table.NextRule(e) 127 | if err != nil { 128 | fmt.Fprintf(os.Stderr, "dump-table-rules: %s\n", err) 129 | os.Exit(3) 130 | } 131 | } 132 | 133 | chain, err = table.NextChain() 134 | if err != nil { 135 | fmt.Fprintf(os.Stderr, "dump-table-rules: %s\n", err) 136 | os.Exit(3) 137 | } 138 | } 139 | } 140 | } 141 | -------------------------------------------------------------------------------- /examples/lock/lock.go: -------------------------------------------------------------------------------- 1 | /* 2 | * go-libiptc v0.3.1 - libiptc bindings for Go language 3 | * Copyright (C) 2015 gdm85 - https://github.com/gdm85/go-libiptc/ 4 | 5 | This program is free software; you can redistribute it and/or 6 | modify it under the terms of the GNU General Public License 7 | as published by the Free Software Foundation; either version 2 8 | of the License, or (at your option) any later version. 9 | 10 | This program is distributed in the hope that it will be useful, 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 | GNU General Public License for more details. 14 | 15 | You should have received a copy of the GNU General Public License 16 | along with this program; if not, write to the Free Software 17 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 18 | */ 19 | 20 | package main 21 | 22 | import ( 23 | "fmt" 24 | "os" 25 | "time" 26 | 27 | "github.com/gdm85/go-libiptc" 28 | ) 29 | 30 | func main() { 31 | fmt.Println("acquiring xtables lock immediately...") 32 | acquired, err := libiptc.XtablesLock(false, 0) 33 | if err != nil { 34 | panic(err) 35 | } 36 | if !acquired { 37 | fmt.Fprintf(os.Stderr, "Could not acquire xtables lock!\n") 38 | os.Exit(1) 39 | } 40 | defer func() { 41 | _, err := libiptc.XtablesUnlock() 42 | if err != nil { 43 | panic(err) 44 | } 45 | }() 46 | 47 | fmt.Printf("I have acquired a lock for 5 seconds, try any 'iptables --wait' command\n") 48 | time.Sleep(5 * time.Second) 49 | } 50 | -------------------------------------------------------------------------------- /libip4tc/libip4tc.go: -------------------------------------------------------------------------------- 1 | /* 2 | * go-libiptc v0.3.1 - libiptc bindings for Go language 3 | * Copyright (C) 2015~2016 gdm85 - https://github.com/gdm85/go-libiptc/ 4 | 5 | This program is free software; you can redistribute it and/or 6 | modify it under the terms of the GNU General Public License 7 | as published by the Free Software Foundation; either version 2 8 | of the License, or (at your option) any later version. 9 | 10 | This program is distributed in the hope that it will be useful, 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 | GNU General Public License for more details. 14 | 15 | You should have received a copy of the GNU General Public License 16 | along with this program; if not, write to the Free Software 17 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 18 | */ 19 | 20 | package libip4tc 21 | 22 | // #cgo LDFLAGS: -lip4tc 23 | // #include 24 | // #include 25 | import "C" 26 | 27 | import ( 28 | "net" 29 | "runtime" 30 | "unsafe" 31 | 32 | common "github.com/gdm85/go-libiptc" 33 | ) 34 | 35 | func cuint2ip(cAaddr, cMask C.in_addr_t) *net.IPNet { 36 | addr := uint32(cAaddr) 37 | ip := new(net.IPNet) 38 | ip.IP = net.IPv4(byte(addr&0xff), 39 | byte((addr>>8)&0xff), 40 | byte((addr>>16)&0xff), 41 | byte((addr>>24)&0xff)) 42 | mask := uint32(cMask) 43 | ip.Mask = net.IPv4Mask(byte(mask&0xff), 44 | byte((mask>>8)&0xff), 45 | byte((mask>>16)&0xff), 46 | byte((mask>>24)&0xff), 47 | ) 48 | return ip 49 | } 50 | 51 | type IptEntry struct { 52 | handle *C.struct_ipt_entry 53 | } 54 | 55 | func (h IptEntry) IsEmpty() bool { 56 | return h.handle == nil 57 | } 58 | 59 | type XtcHandle struct { 60 | handle *C.struct_xtc_handle 61 | } 62 | 63 | func (h XtcHandle) IptEntry2Rule(e *IptEntry) *common.Rule { 64 | entry := e.handle 65 | rule := new(common.Rule) 66 | rule.Pcnt = uint64(entry.counters.pcnt) 67 | rule.Bcnt = uint64(entry.counters.bcnt) 68 | rule.InDev = C.GoString(&entry.ip.iniface[0]) 69 | rule.OutDev = C.GoString(&entry.ip.outiface[0]) 70 | if entry.ip.invflags&C.IPT_INV_VIA_IN != 0 { 71 | rule.Not.InDev = true 72 | } 73 | if entry.ip.invflags&C.IPT_INV_VIA_OUT != 0 { 74 | rule.Not.OutDev = true 75 | } 76 | 77 | rule.Src = cuint2ip(entry.ip.src.s_addr, entry.ip.smsk.s_addr) 78 | if entry.ip.invflags&C.IPT_INV_SRCIP != 0 { 79 | rule.Not.Src = true 80 | } 81 | 82 | rule.Dest = cuint2ip(entry.ip.dst.s_addr, entry.ip.dmsk.s_addr) 83 | if entry.ip.invflags&C.IPT_INV_DSTIP != 0 { 84 | rule.Not.Dest = true 85 | } 86 | 87 | target := C.iptc_get_target(entry, h.handle) 88 | if target != nil { 89 | rule.Target = C.GoString(target) 90 | } 91 | return rule 92 | } 93 | 94 | func getNativeError() string { 95 | return C.GoString(C.iptc_strerror(C.int(common.GetErrno()))) 96 | } 97 | 98 | func (h *XtcHandle) Free() error { 99 | return common.RelayCall(func() bool { 100 | if h.handle != nil { 101 | C.iptc_free(h.handle) 102 | h.handle = nil 103 | } 104 | return true 105 | }, "iptc_free", getNativeError) 106 | } 107 | 108 | func TableInit(tableName string) (result XtcHandle, osErr error) { 109 | osErr = common.RelayCall(func() bool { 110 | cStr := C.CString(tableName) 111 | defer C.free(unsafe.Pointer(cStr)) 112 | 113 | h := C.iptc_init(cStr) 114 | result = XtcHandle{h} 115 | 116 | return h != nil 117 | }, "iptc_init", getNativeError) 118 | 119 | // set the finalizer before returning the usable result 120 | runtime.SetFinalizer(&result, (*XtcHandle).Free) 121 | 122 | return 123 | } 124 | 125 | func (h XtcHandle) IsChain(chain string) (result bool, osErr error) { 126 | osErr = common.RelayCall(func() bool { 127 | cStr := C.CString(chain) 128 | defer C.free(unsafe.Pointer(cStr)) 129 | 130 | r := C.iptc_is_chain(cStr, h.handle) 131 | if r == 1 { 132 | result = true 133 | return result 134 | } else if r == 0 { 135 | result = false 136 | return result 137 | } 138 | panic("invalid return value") 139 | }, "iptc_is_chain", getNativeError) 140 | return 141 | } 142 | 143 | func (h XtcHandle) IsBuiltin(chain string) (result bool, osErr error) { 144 | osErr = common.RelayCall(func() bool { 145 | cStr := C.CString(chain) 146 | defer C.free(unsafe.Pointer(cStr)) 147 | 148 | r := C.iptc_builtin(cStr, h.handle) 149 | if r == 1 { 150 | result = true 151 | return result 152 | } else if r == 0 { 153 | result = false 154 | return result 155 | } 156 | panic("invalid return value") 157 | }, "iptc_builtin", getNativeError) 158 | return 159 | } 160 | 161 | /* Iterator functions to run through the chains. Returns NULL at end. */ 162 | func (h XtcHandle) FirstChain() (result string, osErr error) { 163 | osErr = common.RelayCall(func() bool { 164 | cStr := C.iptc_first_chain(h.handle) 165 | if cStr == nil { 166 | result = "" 167 | return common.GetErrno() == 0 168 | } 169 | 170 | result = C.GoString(cStr) 171 | return true 172 | }, "iptc_first_chain", getNativeError) 173 | return 174 | } 175 | 176 | func (h XtcHandle) NextChain() (result string, osErr error) { 177 | osErr = common.RelayCall(func() bool { 178 | cStr := C.iptc_next_chain(h.handle) 179 | if cStr == nil { 180 | result = "" 181 | return common.GetErrno() == 0 182 | } 183 | 184 | result = C.GoString(cStr) 185 | return true 186 | }, "iptc_next_chain", getNativeError) 187 | return 188 | } 189 | 190 | /* Get first rule in the given chain: NULL for empty chain. */ 191 | func (h XtcHandle) FirstRule(chain string) (result IptEntry, osErr error) { 192 | osErr = common.RelayCall(func() bool { 193 | cStr := C.CString(chain) 194 | defer C.free(unsafe.Pointer(cStr)) 195 | 196 | result.handle = C.iptc_first_rule(cStr, h.handle) 197 | 198 | if result.handle == nil && common.GetErrno() != 0 { 199 | // there's some error 200 | return false 201 | } 202 | 203 | return true 204 | }, "iptc_first_rule", getNativeError) 205 | return 206 | } 207 | 208 | /* Returns NULL when rules run out. */ 209 | func (h XtcHandle) NextRule(previous IptEntry) (result IptEntry, osErr error) { 210 | osErr = common.RelayCall(func() bool { 211 | result.handle = C.iptc_next_rule(previous.handle, h.handle) 212 | 213 | if result.handle == nil && common.GetErrno() != 0 { 214 | // there's some error 215 | return false 216 | } 217 | 218 | return true 219 | }, "iptc_next_rule", getNativeError) 220 | return 221 | } 222 | 223 | /* Returns a pointer to the target name of this entry. */ 224 | func (h XtcHandle) GetTarget(entry IptEntry) (result string, osErr error) { 225 | osErr = common.RelayCall(func() bool { 226 | cStr := C.iptc_get_target(entry.handle, h.handle) 227 | if cStr == nil { 228 | result = "" 229 | return false 230 | } 231 | 232 | result = C.GoString(cStr) 233 | return true 234 | }, "iptc_get_target", getNativeError) 235 | return 236 | } 237 | 238 | /* Get the policy of a given built-in chain */ 239 | func (h XtcHandle) GetPolicy(chain string) (policy string, counters common.XtCounters, osErr error) { 240 | osErr = common.RelayCall(func() bool { 241 | cStr := C.CString(chain) 242 | defer C.free(unsafe.Pointer(cStr)) 243 | 244 | var c _Ctype_struct_xt_counters 245 | cStr = C.iptc_get_policy(cStr, &c, h.handle) 246 | if cStr == nil { 247 | // no chains 248 | policy = "" 249 | return false 250 | } 251 | 252 | policy = C.GoString(cStr) 253 | counters.Bcnt = uint64(c.bcnt) 254 | counters.Pcnt = uint64(c.pcnt) 255 | return true 256 | }, "iptc_get_policy", getNativeError) 257 | return 258 | } 259 | 260 | /* These functions return TRUE for OK or 0 and set errno. If errno == 261 | 0, it means there was a version error (ie. upgrade libiptc). */ 262 | /* Rule numbers start at 1 for the first rule. */ 263 | 264 | /* Insert the entry `e' in chain `chain' into position `rulenum'. */ 265 | func (h XtcHandle) InsertEntry(chain common.XtChainLabel, entry IptEntry, ruleNum uint) error { 266 | return common.RelayCall(func() bool { 267 | cStr := C.CString(string(chain)) 268 | defer C.free(unsafe.Pointer(cStr)) 269 | 270 | r := C.iptc_insert_entry(cStr, entry.handle, C.uint(ruleNum), h.handle) 271 | if r == 1 { 272 | return true 273 | } else if r == 0 { 274 | // has error 275 | return false 276 | } 277 | 278 | panic("invalid return value") 279 | }, "iptc_insert_entry", getNativeError) 280 | } 281 | 282 | /* Append entry `e' to chain `chain'. Equivalent to insert with 283 | rulenum = length of chain. */ 284 | func (h XtcHandle) AppendEntry(chain common.XtChainLabel, entry IptEntry) error { 285 | return common.RelayCall(func() bool { 286 | cStr := C.CString(string(chain)) 287 | defer C.free(unsafe.Pointer(cStr)) 288 | 289 | r := C.iptc_append_entry(cStr, entry.handle, h.handle) 290 | if r == 1 { 291 | return true 292 | } else if r == 0 { 293 | // has error 294 | return false 295 | } 296 | 297 | panic("invalid return value") 298 | }, "iptc_append_entry", getNativeError) 299 | } 300 | 301 | /* Check whether a matching rule exists */ 302 | func (h XtcHandle) CheckEntry(chain common.XtChainLabel, origfw IptEntry, matchMask []byte) (result bool, osErr error) { 303 | osErr = common.RelayCall(func() bool { 304 | cStr := C.CString(string(chain)) 305 | defer C.free(unsafe.Pointer(cStr)) 306 | cMask := (*C.uchar)(unsafe.Pointer(&matchMask[0])) 307 | 308 | r := C.iptc_check_entry(cStr, origfw.handle, cMask, h.handle) 309 | if r == 1 { 310 | result = true 311 | return result 312 | } else if r == 0 { 313 | result = false 314 | return result 315 | } 316 | 317 | panic("invalid return value") 318 | }, "iptc_check_entry", getNativeError) 319 | return 320 | } 321 | 322 | /* Delete the first rule in `chain' which matches `e', subject to 323 | matchmask (array of length == origfw) */ 324 | func (h XtcHandle) DeleteEntry(chain common.XtChainLabel, origfw IptEntry, matchMask []byte) (result bool, osErr error) { 325 | osErr = common.RelayCall(func() bool { 326 | cStr := C.CString(string(chain)) 327 | defer C.free(unsafe.Pointer(cStr)) 328 | cMask := (*C.uchar)(unsafe.Pointer(&matchMask[0])) 329 | 330 | r := C.iptc_delete_entry(cStr, origfw.handle, cMask, h.handle) 331 | if r == 1 { 332 | result = true 333 | return result 334 | } else if r == 0 { 335 | result = false 336 | return result 337 | } 338 | 339 | panic("invalid return value") 340 | }, "iptc_delete_entry", getNativeError) 341 | return 342 | } 343 | 344 | /* Delete the rule in position `rulenum' in `chain'. */ 345 | func (h XtcHandle) DeleteNumEntry(chain common.XtChainLabel, ruleNum uint) (result bool, osErr error) { 346 | osErr = common.RelayCall(func() bool { 347 | cStr := C.CString(string(chain)) 348 | defer C.free(unsafe.Pointer(cStr)) 349 | 350 | r := C.iptc_delete_num_entry(cStr, C.uint(ruleNum), h.handle) 351 | if r == 1 { 352 | result = true 353 | return result 354 | } else if r == 0 { 355 | result = false 356 | return result 357 | } 358 | 359 | panic("invalid return value") 360 | }, "iptc_delete_num_entry", getNativeError) 361 | return 362 | } 363 | 364 | /* Flushes the entries in the given chain (ie. empties chain). */ 365 | func (h XtcHandle) FlushEntries(chain common.XtChainLabel) (result bool, osErr error) { 366 | osErr = common.RelayCall(func() bool { 367 | cStr := C.CString(string(chain)) 368 | defer C.free(unsafe.Pointer(cStr)) 369 | 370 | r := C.iptc_flush_entries(cStr, h.handle) 371 | if r == 1 { 372 | result = true 373 | return result 374 | } else if r == 0 { 375 | result = false 376 | return result 377 | } 378 | 379 | panic("invalid return value") 380 | }, "iptc_flush_entries", getNativeError) 381 | return 382 | } 383 | 384 | /* Zeroes the counters in a chain. */ 385 | func (h XtcHandle) ZeroEntries(chain common.XtChainLabel) (result bool, osErr error) { 386 | osErr = common.RelayCall(func() bool { 387 | cStr := C.CString(string(chain)) 388 | defer C.free(unsafe.Pointer(cStr)) 389 | 390 | r := C.iptc_zero_entries(cStr, h.handle) 391 | if r == 1 { 392 | result = true 393 | return result 394 | } else if r == 0 { 395 | result = false 396 | return result 397 | } 398 | 399 | panic("invalid return value") 400 | }, "iptc_zero_entries", getNativeError) 401 | return 402 | } 403 | 404 | /* Creates a new chain. */ 405 | func (h XtcHandle) CreateChain(chain common.XtChainLabel) (result bool, osErr error) { 406 | osErr = common.RelayCall(func() bool { 407 | cStr := C.CString(string(chain)) 408 | defer C.free(unsafe.Pointer(cStr)) 409 | 410 | r := C.iptc_create_chain(cStr, h.handle) 411 | if r == 1 { 412 | result = true 413 | return result 414 | } else if r == 0 { 415 | result = false 416 | return result 417 | } 418 | 419 | panic("invalid return value") 420 | }, "iptc_create_chain", getNativeError) 421 | return 422 | } 423 | 424 | /* Deletes a chain. */ 425 | func (h XtcHandle) DeleteChain(chain common.XtChainLabel) (result bool, osErr error) { 426 | osErr = common.RelayCall(func() bool { 427 | cStr := C.CString(string(chain)) 428 | defer C.free(unsafe.Pointer(cStr)) 429 | 430 | r := C.iptc_delete_chain(cStr, h.handle) 431 | if r == 1 { 432 | result = true 433 | return result 434 | } else if r == 0 { 435 | result = false 436 | return result 437 | } 438 | 439 | panic("invalid return value") 440 | }, "iptc_delete_chain", getNativeError) 441 | return 442 | } 443 | 444 | /* Renames a chain. */ 445 | func (h XtcHandle) RenameChain(oldName, newName common.XtChainLabel) (result bool, osErr error) { 446 | osErr = common.RelayCall(func() bool { 447 | cOldName := C.CString(string(oldName)) 448 | defer C.free(unsafe.Pointer(cOldName)) 449 | cNewName := C.CString(string(newName)) 450 | defer C.free(unsafe.Pointer(cNewName)) 451 | 452 | r := C.iptc_rename_chain(cOldName, cNewName, h.handle) 453 | if r == 1 { 454 | result = true 455 | return result 456 | } else if r == 0 { 457 | result = false 458 | return result 459 | } 460 | 461 | panic("invalid return value") 462 | }, "iptc_rename_chain", getNativeError) 463 | return 464 | } 465 | 466 | /* Sets the policy and (optionally) counters on a built-in chain. */ 467 | func (h XtcHandle) SetPolicy(chain, policy common.XtChainLabel, counters *common.XtCounters) (result bool, osErr error) { 468 | osErr = common.RelayCall(func() bool { 469 | cChain := C.CString(string(chain)) 470 | defer C.free(unsafe.Pointer(cChain)) 471 | cPolicy := C.CString(string(policy)) 472 | defer C.free(unsafe.Pointer(cPolicy)) 473 | 474 | var c *_Ctype_struct_xt_counters 475 | if counters != nil { 476 | c = &_Ctype_struct_xt_counters{} 477 | c.bcnt = C.__u64(counters.Bcnt) 478 | c.pcnt = C.__u64(counters.Pcnt) 479 | } 480 | 481 | r := C.iptc_set_policy(cChain, cPolicy, c, h.handle) 482 | if r == 1 { 483 | result = true 484 | return result 485 | } else if r == 0 { 486 | result = false 487 | return result 488 | } 489 | 490 | panic("invalid return value") 491 | }, "iptc_set_policy", getNativeError) 492 | return 493 | } 494 | 495 | /* Get the number of references to this chain */ 496 | func (h XtcHandle) GetReferences(chain common.XtChainLabel) (result uint, osErr error) { 497 | osErr = common.RelayCall(func() bool { 498 | cStr := C.CString(string(chain)) 499 | defer C.free(unsafe.Pointer(cStr)) 500 | 501 | var i C.uint 502 | 503 | r := C.iptc_get_references(&i, cStr, h.handle) 504 | if r == 1 { 505 | // has a valid result 506 | result = uint(i) 507 | return true 508 | } else if r == 0 { 509 | // has an error 510 | return false 511 | } 512 | 513 | panic("invalid return value") 514 | }, "iptc_get_references", getNativeError) 515 | return 516 | } 517 | 518 | /* read packet and byte counters for a specific rule */ 519 | func (h XtcHandle) ReadCounter(chain common.XtChainLabel, ruleNum uint) (result common.XtCounters, osErr error) { 520 | osErr = common.RelayCall(func() bool { 521 | cStr := C.CString(string(chain)) 522 | defer C.free(unsafe.Pointer(cStr)) 523 | 524 | counters_handle := C.iptc_read_counter(cStr, C.uint(ruleNum), h.handle) 525 | if counters_handle == nil { 526 | // has an error 527 | return false 528 | } 529 | 530 | result.Bcnt = uint64(counters_handle.bcnt) 531 | result.Pcnt = uint64(counters_handle.pcnt) 532 | return true 533 | }, "iptc_read_counter", getNativeError) 534 | return 535 | } 536 | 537 | /* zero packet and byte counters for a specific rule */ 538 | func (h XtcHandle) ZeroCounter(chain common.XtChainLabel, ruleNum uint) (result bool, osErr error) { 539 | osErr = common.RelayCall(func() bool { 540 | cStr := C.CString(string(chain)) 541 | defer C.free(unsafe.Pointer(cStr)) 542 | 543 | r := C.iptc_zero_counter(cStr, C.uint(ruleNum), h.handle) 544 | if r == 1 { 545 | result = true 546 | return result 547 | } else if r == 0 { 548 | result = false 549 | return result 550 | } 551 | 552 | panic("invalid return value") 553 | }, "iptc_read_counter", getNativeError) 554 | return 555 | } 556 | 557 | // SetCounter sets packet and byte counters for a specific rule. 558 | func (h XtcHandle) SetCounter(chain common.XtChainLabel, ruleNum uint, counters common.XtCounters) (result bool, osErr error) { 559 | osErr = common.RelayCall(func() bool { 560 | cStr := C.CString(string(chain)) 561 | defer C.free(unsafe.Pointer(cStr)) 562 | 563 | var c _Ctype_struct_xt_counters 564 | c.bcnt = C.__u64(counters.Bcnt) 565 | c.pcnt = C.__u64(counters.Pcnt) 566 | 567 | r := C.iptc_set_counter(cStr, C.uint(ruleNum), &c, h.handle) 568 | if r == 1 { 569 | result = true 570 | return result 571 | } else if r == 0 { 572 | result = false 573 | return result 574 | } 575 | 576 | panic("invalid return value") 577 | }, "iptc_set_counter", getNativeError) 578 | return 579 | } 580 | 581 | // Commit makes the actual changes. 582 | func (h XtcHandle) Commit() error { 583 | return common.RelayCall(func() bool { 584 | r := C.iptc_commit(h.handle) 585 | if r == 1 { 586 | return true 587 | } else if r == 0 { 588 | return false 589 | } 590 | 591 | panic("unexpected return value") 592 | }, "iptc_commit", getNativeError) 593 | } 594 | 595 | // DumpEntries will use an internal undocumented function to dump all table entries to stdout. 596 | func (h XtcHandle) DumpEntries() error { 597 | return common.RelayCall(func() bool { 598 | C.dump_entries(h.handle) 599 | return false 600 | }, "dump_entries", getNativeError) 601 | } 602 | -------------------------------------------------------------------------------- /libip4tc/libip4tc_test.go: -------------------------------------------------------------------------------- 1 | /* 2 | * go-libiptc v0.3.1 - libiptc bindings for Go language 3 | * Copyright (C) 2015~2016 gdm85 - https://github.com/gdm85/go-libiptc/ 4 | 5 | This program is free software; you can redistribute it and/or 6 | modify it under the terms of the GNU General Public License 7 | as published by the Free Software Foundation; either version 2 8 | of the License, or (at your option) any later version. 9 | 10 | This program is distributed in the hope that it will be useful, 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 | GNU General Public License for more details. 14 | 15 | You should have received a copy of the GNU General Public License 16 | along with this program; if not, write to the Free Software 17 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 18 | */ 19 | 20 | package libip4tc 21 | 22 | import ( 23 | "testing" 24 | 25 | common "github.com/gdm85/go-libiptc" 26 | ) 27 | 28 | func TestXtablesLock(t *testing.T) { 29 | acquired, err := common.XtablesLock(false, 0) 30 | if err != nil { 31 | t.Error(err) 32 | t.FailNow() 33 | } 34 | if !acquired { 35 | t.FailNow() 36 | } 37 | 38 | released, err := common.XtablesUnlock() 39 | if err != nil { 40 | t.Error(err) 41 | t.FailNow() 42 | } 43 | 44 | released, err = common.XtablesUnlock() 45 | if err == nil || released { 46 | t.Error("unlocking twice succeeded!") 47 | t.FailNow() 48 | } 49 | } 50 | 51 | func TestInit(t *testing.T) { 52 | acquired, err := common.XtablesLock(false, 0) 53 | if err != nil { 54 | t.Fatal(err) 55 | } 56 | if !acquired { 57 | t.FailNow() 58 | } 59 | defer func() { 60 | _, err := common.XtablesUnlock() 61 | if err != nil { 62 | panic(err) 63 | } 64 | }() 65 | 66 | handle, err := TableInit("filter") 67 | if err != nil { 68 | t.Fatal(err) 69 | } 70 | 71 | err = handle.Free() 72 | if err != nil { 73 | t.Fatal(err) 74 | } 75 | } 76 | -------------------------------------------------------------------------------- /libip6tc/libip6tc.go: -------------------------------------------------------------------------------- 1 | /* 2 | * go-libiptc v0.3.1 - libiptc bindings for Go language 3 | * Copyright (C) 2015~2016 gdm85 - https://github.com/gdm85/go-libiptc/ 4 | 5 | This program is free software; you can redistribute it and/or 6 | modify it under the terms of the GNU General Public License 7 | as published by the Free Software Foundation; either version 2 8 | of the License, or (at your option) any later version. 9 | 10 | This program is distributed in the hope that it will be useful, 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 | GNU General Public License for more details. 14 | 15 | You should have received a copy of the GNU General Public License 16 | along with this program; if not, write to the Free Software 17 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 18 | */ 19 | 20 | package libip6tc 21 | 22 | import ( 23 | // #cgo LDFLAGS: -lip6tc 24 | // #include 25 | // #include 26 | "C" 27 | "net" 28 | "runtime" 29 | "unsafe" 30 | 31 | common "github.com/gdm85/go-libiptc" 32 | ) 33 | 34 | func cin6addr2ip(cAaddr, cMask C.struct_in6_addr) *net.IPNet { 35 | ip := new(net.IPNet) 36 | 37 | ip.IP = make(net.IP, 16) 38 | copy(ip.IP, cAaddr.__in6_u[:]) 39 | ip.Mask = make(net.IPMask, 16) 40 | copy(ip.Mask, cMask.__in6_u[:]) 41 | 42 | return ip 43 | } 44 | 45 | type IptEntry struct { 46 | handle *C.struct_ip6t_entry 47 | } 48 | 49 | func (h IptEntry) IsEmpty() bool { 50 | return h.handle == nil 51 | } 52 | 53 | type XtcHandle struct { 54 | handle *C.struct_xtc_handle 55 | } 56 | 57 | func (h XtcHandle) IptEntry2Rule(e *IptEntry) *common.Rule { 58 | entry := e.handle 59 | rule := new(common.Rule) 60 | rule.Pcnt = uint64(entry.counters.pcnt) 61 | rule.Bcnt = uint64(entry.counters.bcnt) 62 | rule.InDev = C.GoString(&entry.ipv6.iniface[0]) 63 | rule.OutDev = C.GoString(&entry.ipv6.outiface[0]) 64 | if entry.ipv6.invflags&C.IP6T_INV_VIA_IN != 0 { 65 | rule.Not.InDev = true 66 | } 67 | if entry.ipv6.invflags&C.IP6T_INV_VIA_OUT != 0 { 68 | rule.Not.OutDev = true 69 | } 70 | 71 | rule.Src = cin6addr2ip(entry.ipv6.src, entry.ipv6.smsk) 72 | if entry.ipv6.invflags&C.IP6T_INV_SRCIP != 0 { 73 | rule.Not.Src = true 74 | } 75 | 76 | rule.Dest = cin6addr2ip(entry.ipv6.dst, entry.ipv6.dmsk) 77 | if entry.ipv6.invflags&C.IP6T_INV_DSTIP != 0 { 78 | rule.Not.Dest = true 79 | } 80 | 81 | target := C.ip6tc_get_target(entry, h.handle) 82 | if target != nil { 83 | rule.Target = C.GoString(target) 84 | } 85 | return rule 86 | } 87 | 88 | func getNativeError() string { 89 | return C.GoString(C.ip6tc_strerror(C.int(common.GetErrno()))) 90 | } 91 | 92 | func (h *XtcHandle) Free() error { 93 | return common.RelayCall(func() bool { 94 | if h.handle != nil { 95 | C.ip6tc_free(h.handle) 96 | h.handle = nil 97 | } 98 | return true 99 | }, "ip6tc_free", getNativeError) 100 | } 101 | 102 | func TableInit(tableName string) (result XtcHandle, osErr error) { 103 | osErr = common.RelayCall(func() bool { 104 | cStr := C.CString(tableName) 105 | defer C.free(unsafe.Pointer(cStr)) 106 | 107 | h := C.ip6tc_init(cStr) 108 | result = XtcHandle{h} 109 | 110 | return h != nil 111 | }, "ip6tc_init", getNativeError) 112 | 113 | // set the finalizer before returning the usable result 114 | runtime.SetFinalizer(&result, (*XtcHandle).Free) 115 | 116 | return 117 | } 118 | 119 | func (h XtcHandle) IsChain(chain string) (result bool, osErr error) { 120 | osErr = common.RelayCall(func() bool { 121 | cStr := C.CString(chain) 122 | defer C.free(unsafe.Pointer(cStr)) 123 | 124 | r := C.ip6tc_is_chain(cStr, h.handle) 125 | if r == 1 { 126 | result = true 127 | return result 128 | } else if r == 0 { 129 | result = false 130 | return result 131 | } 132 | panic("invalid return value") 133 | }, "ip6tc_is_chain", getNativeError) 134 | return 135 | } 136 | 137 | func (h XtcHandle) IsBuiltin(chain string) (result bool, osErr error) { 138 | osErr = common.RelayCall(func() bool { 139 | cStr := C.CString(chain) 140 | defer C.free(unsafe.Pointer(cStr)) 141 | 142 | r := C.ip6tc_builtin(cStr, h.handle) 143 | if r == 1 { 144 | result = true 145 | return result 146 | } else if r == 0 { 147 | result = false 148 | return result 149 | } 150 | panic("invalid return value") 151 | }, "ip6tc_builtin", getNativeError) 152 | return 153 | } 154 | 155 | /* Iterator functions to run through the chains. Returns NULL at end. */ 156 | func (h XtcHandle) FirstChain() (result string, osErr error) { 157 | osErr = common.RelayCall(func() bool { 158 | cStr := C.ip6tc_first_chain(h.handle) 159 | if cStr == nil { 160 | result = "" 161 | return common.GetErrno() == 0 162 | } 163 | 164 | result = C.GoString(cStr) 165 | return true 166 | }, "ip6tc_first_chain", getNativeError) 167 | return 168 | } 169 | 170 | func (h XtcHandle) NextChain() (result string, osErr error) { 171 | osErr = common.RelayCall(func() bool { 172 | cStr := C.ip6tc_next_chain(h.handle) 173 | if cStr == nil { 174 | result = "" 175 | return common.GetErrno() == 0 176 | } 177 | 178 | result = C.GoString(cStr) 179 | return true 180 | }, "ip6tc_next_chain", getNativeError) 181 | return 182 | } 183 | 184 | /* Get first rule in the given chain: NULL for empty chain. */ 185 | func (h XtcHandle) FirstRule(chain string) (result IptEntry, osErr error) { 186 | osErr = common.RelayCall(func() bool { 187 | cStr := C.CString(chain) 188 | defer C.free(unsafe.Pointer(cStr)) 189 | 190 | result.handle = C.ip6tc_first_rule(cStr, h.handle) 191 | 192 | if result.handle == nil && common.GetErrno() != 0 { 193 | // there's some error 194 | return false 195 | } 196 | 197 | return true 198 | }, "ip6tc_first_rule", getNativeError) 199 | return 200 | } 201 | 202 | /* Returns NULL when rules run out. */ 203 | func (h XtcHandle) NextRule(previous IptEntry) (result IptEntry, osErr error) { 204 | osErr = common.RelayCall(func() bool { 205 | result.handle = C.ip6tc_next_rule(previous.handle, h.handle) 206 | 207 | if result.handle == nil && common.GetErrno() != 0 { 208 | // there's some error 209 | return false 210 | } 211 | 212 | return true 213 | }, "ip6tc_next_rule", getNativeError) 214 | return 215 | } 216 | 217 | /* Returns a pointer to the target name of this entry. */ 218 | func (h XtcHandle) GetTarget(entry IptEntry) (result string, osErr error) { 219 | osErr = common.RelayCall(func() bool { 220 | cStr := C.ip6tc_get_target(entry.handle, h.handle) 221 | if cStr == nil { 222 | result = "" 223 | return false 224 | } 225 | 226 | result = C.GoString(cStr) 227 | return true 228 | }, "ip6tc_get_target", getNativeError) 229 | return 230 | } 231 | 232 | // GetPolicy gets the policy of a given built-in chain. 233 | func (h XtcHandle) GetPolicy(chain string) (policy string, counters common.XtCounters, osErr error) { 234 | osErr = common.RelayCall(func() bool { 235 | cStr := C.CString(chain) 236 | defer C.free(unsafe.Pointer(cStr)) 237 | 238 | var c _Ctype_struct_xt_counters 239 | cStr = C.ip6tc_get_policy(cStr, &c, h.handle) 240 | if cStr == nil { 241 | // no chains 242 | policy = "" 243 | return false 244 | } 245 | 246 | policy = C.GoString(cStr) 247 | counters.Bcnt = uint64(c.bcnt) 248 | counters.Pcnt = uint64(c.pcnt) 249 | return true 250 | }, "ip6tc_get_policy", getNativeError) 251 | return 252 | } 253 | 254 | /* These functions return TRUE for OK or 0 and set errno. If errno == 255 | 0, it means there was a version error (ie. upgrade libiptc). */ 256 | /* Rule numbers start at 1 for the first rule. */ 257 | 258 | /* Insert the entry `e' in chain `chain' into position `rulenum'. */ 259 | func (h XtcHandle) InsertEntry(chain common.XtChainLabel, entry IptEntry, ruleNum uint) error { 260 | return common.RelayCall(func() bool { 261 | cStr := C.CString(string(chain)) 262 | defer C.free(unsafe.Pointer(cStr)) 263 | 264 | r := C.ip6tc_insert_entry(cStr, entry.handle, C.uint(ruleNum), h.handle) 265 | if r == 1 { 266 | return true 267 | } else if r == 0 { 268 | // has error 269 | return false 270 | } 271 | 272 | panic("invalid return value") 273 | }, "ip6tc_insert_entry", getNativeError) 274 | } 275 | 276 | /* Append entry `e' to chain `chain'. Equivalent to insert with 277 | rulenum = length of chain. */ 278 | func (h XtcHandle) AppendEntry(chain common.XtChainLabel, entry IptEntry) error { 279 | return common.RelayCall(func() bool { 280 | cStr := C.CString(string(chain)) 281 | defer C.free(unsafe.Pointer(cStr)) 282 | 283 | r := C.ip6tc_append_entry(cStr, entry.handle, h.handle) 284 | if r == 1 { 285 | return true 286 | } else if r == 0 { 287 | // has error 288 | return false 289 | } 290 | 291 | panic("invalid return value") 292 | }, "ip6tc_append_entry", getNativeError) 293 | } 294 | 295 | /* Check whether a matching rule exists */ 296 | func (h XtcHandle) CheckEntry(chain common.XtChainLabel, origfw IptEntry, matchMask []byte) (result bool, osErr error) { 297 | osErr = common.RelayCall(func() bool { 298 | cStr := C.CString(string(chain)) 299 | defer C.free(unsafe.Pointer(cStr)) 300 | cMask := (*C.uchar)(unsafe.Pointer(&matchMask[0])) 301 | 302 | r := C.ip6tc_check_entry(cStr, origfw.handle, cMask, h.handle) 303 | if r == 1 { 304 | result = true 305 | return result 306 | } else if r == 0 { 307 | result = false 308 | return result 309 | } 310 | 311 | panic("invalid return value") 312 | }, "ip6tc_check_entry", getNativeError) 313 | return 314 | } 315 | 316 | /* Delete the first rule in `chain' which matches `e', subject to 317 | matchmask (array of length == origfw) */ 318 | func (h XtcHandle) DeleteEntry(chain common.XtChainLabel, origfw IptEntry, matchMask []byte) (result bool, osErr error) { 319 | osErr = common.RelayCall(func() bool { 320 | cStr := C.CString(string(chain)) 321 | defer C.free(unsafe.Pointer(cStr)) 322 | cMask := (*C.uchar)(unsafe.Pointer(&matchMask[0])) 323 | 324 | r := C.ip6tc_delete_entry(cStr, origfw.handle, cMask, h.handle) 325 | if r == 1 { 326 | result = true 327 | return result 328 | } else if r == 0 { 329 | result = false 330 | return result 331 | } 332 | 333 | panic("invalid return value") 334 | }, "ip6tc_delete_entry", getNativeError) 335 | return 336 | } 337 | 338 | /* Delete the rule in position `rulenum' in `chain'. */ 339 | func (h XtcHandle) DeleteNumEntry(chain common.XtChainLabel, ruleNum uint) (result bool, osErr error) { 340 | osErr = common.RelayCall(func() bool { 341 | cStr := C.CString(string(chain)) 342 | defer C.free(unsafe.Pointer(cStr)) 343 | 344 | r := C.ip6tc_delete_num_entry(cStr, C.uint(ruleNum), h.handle) 345 | if r == 1 { 346 | result = true 347 | return result 348 | } else if r == 0 { 349 | result = false 350 | return result 351 | } 352 | 353 | panic("invalid return value") 354 | }, "ip6tc_delete_num_entry", getNativeError) 355 | return 356 | } 357 | 358 | /* Flushes the entries in the given chain (ie. empties chain). */ 359 | func (h XtcHandle) FlushEntries(chain common.XtChainLabel) (result bool, osErr error) { 360 | osErr = common.RelayCall(func() bool { 361 | cStr := C.CString(string(chain)) 362 | defer C.free(unsafe.Pointer(cStr)) 363 | 364 | r := C.ip6tc_flush_entries(cStr, h.handle) 365 | if r == 1 { 366 | result = true 367 | return result 368 | } else if r == 0 { 369 | result = false 370 | return result 371 | } 372 | 373 | panic("invalid return value") 374 | }, "ip6tc_flush_entries", getNativeError) 375 | return 376 | } 377 | 378 | /* Zeroes the counters in a chain. */ 379 | func (h XtcHandle) ZeroEntries(chain common.XtChainLabel) (result bool, osErr error) { 380 | osErr = common.RelayCall(func() bool { 381 | cStr := C.CString(string(chain)) 382 | defer C.free(unsafe.Pointer(cStr)) 383 | 384 | r := C.ip6tc_zero_entries(cStr, h.handle) 385 | if r == 1 { 386 | result = true 387 | return result 388 | } else if r == 0 { 389 | result = false 390 | return result 391 | } 392 | 393 | panic("invalid return value") 394 | }, "ip6tc_zero_entries", getNativeError) 395 | return 396 | } 397 | 398 | /* Creates a new chain. */ 399 | func (h XtcHandle) CreateChain(chain common.XtChainLabel) (result bool, osErr error) { 400 | osErr = common.RelayCall(func() bool { 401 | cStr := C.CString(string(chain)) 402 | defer C.free(unsafe.Pointer(cStr)) 403 | 404 | r := C.ip6tc_create_chain(cStr, h.handle) 405 | if r == 1 { 406 | result = true 407 | return result 408 | } else if r == 0 { 409 | result = false 410 | return result 411 | } 412 | 413 | panic("invalid return value") 414 | }, "ip6tc_create_chain", getNativeError) 415 | return 416 | } 417 | 418 | /* Deletes a chain. */ 419 | func (h XtcHandle) DeleteChain(chain common.XtChainLabel) (result bool, osErr error) { 420 | osErr = common.RelayCall(func() bool { 421 | cStr := C.CString(string(chain)) 422 | defer C.free(unsafe.Pointer(cStr)) 423 | 424 | r := C.ip6tc_delete_chain(cStr, h.handle) 425 | if r == 1 { 426 | result = true 427 | return result 428 | } else if r == 0 { 429 | result = false 430 | return result 431 | } 432 | 433 | panic("invalid return value") 434 | }, "ip6tc_delete_chain", getNativeError) 435 | return 436 | } 437 | 438 | /* Renames a chain. */ 439 | func (h XtcHandle) RenameChain(oldName, newName common.XtChainLabel) (result bool, osErr error) { 440 | osErr = common.RelayCall(func() bool { 441 | cOldName := C.CString(string(oldName)) 442 | defer C.free(unsafe.Pointer(cOldName)) 443 | cNewName := C.CString(string(newName)) 444 | defer C.free(unsafe.Pointer(cNewName)) 445 | 446 | r := C.ip6tc_rename_chain(cOldName, cNewName, h.handle) 447 | if r == 1 { 448 | result = true 449 | return result 450 | } else if r == 0 { 451 | result = false 452 | return result 453 | } 454 | 455 | panic("invalid return value") 456 | }, "ip6tc_rename_chain", getNativeError) 457 | return 458 | } 459 | 460 | /* Sets the policy and (optionally) counters on a built-in chain. */ 461 | func (h XtcHandle) SetPolicy(chain, policy common.XtChainLabel, counters *common.XtCounters) (result bool, osErr error) { 462 | osErr = common.RelayCall(func() bool { 463 | cChain := C.CString(string(chain)) 464 | defer C.free(unsafe.Pointer(cChain)) 465 | cPolicy := C.CString(string(policy)) 466 | defer C.free(unsafe.Pointer(cPolicy)) 467 | 468 | var c *_Ctype_struct_xt_counters 469 | if counters != nil { 470 | c = &_Ctype_struct_xt_counters{} 471 | c.bcnt = C.__u64(counters.Bcnt) 472 | c.pcnt = C.__u64(counters.Pcnt) 473 | } 474 | 475 | r := C.ip6tc_set_policy(cChain, cPolicy, c, h.handle) 476 | if r == 1 { 477 | result = true 478 | return result 479 | } else if r == 0 { 480 | result = false 481 | return result 482 | } 483 | 484 | panic("invalid return value") 485 | }, "ip6tc_set_policy", getNativeError) 486 | return 487 | } 488 | 489 | /* Get the number of references to this chain */ 490 | func (h XtcHandle) GetReferences(chain common.XtChainLabel) (result uint, osErr error) { 491 | osErr = common.RelayCall(func() bool { 492 | cStr := C.CString(string(chain)) 493 | defer C.free(unsafe.Pointer(cStr)) 494 | 495 | var i C.uint 496 | 497 | r := C.ip6tc_get_references(&i, cStr, h.handle) 498 | if r == 1 { 499 | // has a valid result 500 | result = uint(i) 501 | return true 502 | } else if r == 0 { 503 | // has an error 504 | return false 505 | } 506 | 507 | panic("invalid return value") 508 | }, "ip6tc_get_references", getNativeError) 509 | return 510 | } 511 | 512 | /* read packet and byte counters for a specific rule */ 513 | func (h XtcHandle) ReadCounter(chain common.XtChainLabel, ruleNum uint) (result common.XtCounters, osErr error) { 514 | osErr = common.RelayCall(func() bool { 515 | cStr := C.CString(string(chain)) 516 | defer C.free(unsafe.Pointer(cStr)) 517 | 518 | counters_handle := C.ip6tc_read_counter(cStr, C.uint(ruleNum), h.handle) 519 | if counters_handle == nil { 520 | // has an error 521 | return false 522 | } 523 | 524 | result.Bcnt = uint64(counters_handle.bcnt) 525 | result.Pcnt = uint64(counters_handle.pcnt) 526 | return true 527 | }, "ip6tc_read_counter", getNativeError) 528 | return 529 | } 530 | 531 | /* zero packet and byte counters for a specific rule */ 532 | func (h XtcHandle) ZeroCounter(chain common.XtChainLabel, ruleNum uint) (result bool, osErr error) { 533 | osErr = common.RelayCall(func() bool { 534 | cStr := C.CString(string(chain)) 535 | defer C.free(unsafe.Pointer(cStr)) 536 | 537 | r := C.ip6tc_zero_counter(cStr, C.uint(ruleNum), h.handle) 538 | if r == 1 { 539 | result = true 540 | return result 541 | } else if r == 0 { 542 | result = false 543 | return result 544 | } 545 | 546 | panic("invalid return value") 547 | }, "ip6tc_read_counter", getNativeError) 548 | return 549 | } 550 | 551 | // SetCounter sets packet and byte counters for a specific rule. 552 | func (h XtcHandle) SetCounter(chain common.XtChainLabel, ruleNum uint, counters common.XtCounters) (result bool, osErr error) { 553 | osErr = common.RelayCall(func() bool { 554 | cStr := C.CString(string(chain)) 555 | defer C.free(unsafe.Pointer(cStr)) 556 | 557 | var c _Ctype_struct_xt_counters 558 | c.bcnt = C.__u64(counters.Bcnt) 559 | c.pcnt = C.__u64(counters.Pcnt) 560 | 561 | r := C.ip6tc_set_counter(cStr, C.uint(ruleNum), &c, h.handle) 562 | if r == 1 { 563 | result = true 564 | return result 565 | } else if r == 0 { 566 | result = false 567 | return result 568 | } 569 | 570 | panic("invalid return value") 571 | }, "ip6tc_set_counter", getNativeError) 572 | return 573 | } 574 | 575 | // Commit makes the actual changes. 576 | func (h XtcHandle) Commit() error { 577 | return common.RelayCall(func() bool { 578 | r := C.ip6tc_commit(h.handle) 579 | if r == 1 { 580 | return true 581 | } else if r == 0 { 582 | return false 583 | } 584 | 585 | panic("unexpected return value") 586 | }, "ip6tc_commit", getNativeError) 587 | } 588 | 589 | // DumpEntries will use an internal undocumented function to dump all table entries to stdout. 590 | func (h XtcHandle) DumpEntries() error { 591 | return common.RelayCall(func() bool { 592 | C.dump_entries6(h.handle) 593 | return false 594 | }, "dump_entries6", getNativeError) 595 | } 596 | -------------------------------------------------------------------------------- /libip6tc/libip6tc_test.go: -------------------------------------------------------------------------------- 1 | /* 2 | * go-libiptc v0.3.1 - libiptc bindings for Go language 3 | * Copyright (C) 2015~2016 gdm85 - https://github.com/gdm85/go-libiptc/ 4 | 5 | This program is free software; you can redistribute it and/or 6 | modify it under the terms of the GNU General Public License 7 | as published by the Free Software Foundation; either version 2 8 | of the License, or (at your option) any later version. 9 | 10 | This program is distributed in the hope that it will be useful, 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 | GNU General Public License for more details. 14 | 15 | You should have received a copy of the GNU General Public License 16 | along with this program; if not, write to the Free Software 17 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 18 | */ 19 | 20 | package libip6tc 21 | 22 | import ( 23 | "testing" 24 | 25 | common "github.com/gdm85/go-libiptc" 26 | ) 27 | 28 | func TestInit(t *testing.T) { 29 | acquired, err := common.XtablesLock(false, 0) 30 | if err != nil { 31 | t.Error(err) 32 | t.FailNow() 33 | } 34 | if !acquired { 35 | t.FailNow() 36 | } 37 | defer func() { 38 | _, err := common.XtablesUnlock() 39 | if err != nil { 40 | panic(err) 41 | } 42 | }() 43 | 44 | handle, err := TableInit("filter") 45 | if err != nil { 46 | t.Error(err) 47 | t.FailNow() 48 | } 49 | 50 | err = handle.Free() 51 | if err != nil { 52 | t.Error(err) 53 | t.FailNow() 54 | } 55 | } 56 | -------------------------------------------------------------------------------- /libiptc.go: -------------------------------------------------------------------------------- 1 | /* 2 | * go-libiptc v0.3.1 - libiptc bindings for Go language 3 | * Copyright (C) 2015~2016 gdm85 - https://github.com/gdm85/go-libiptc/ 4 | 5 | This program is free software; you can redistribute it and/or 6 | modify it under the terms of the GNU General Public License 7 | as published by the Free Software Foundation; either version 2 8 | of the License, or (at your option) any later version. 9 | 10 | This program is distributed in the hope that it will be useful, 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 | GNU General Public License for more details. 14 | 15 | You should have received a copy of the GNU General Public License 16 | along with this program; if not, write to the Free Software 17 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 18 | */ 19 | 20 | package libiptc 21 | 22 | import ( 23 | // #cgo LDFLAGS: -liptc 24 | // #include "xtables-lock.h" 25 | "C" 26 | "fmt" 27 | "net" 28 | "runtime" 29 | ) 30 | 31 | // XtChainLabel is a chain label. 32 | type XtChainLabel string 33 | 34 | const ( 35 | // the constants are copied from #define declarations in libiptc.h 36 | IPTC_LABEL_ACCEPT = "ACCEPT" 37 | IPTC_LABEL_DROP = "DROP" 38 | IPTC_LABEL_QUEUE = "QUEUE" 39 | IPTC_LABEL_RETURN = "RETURN" 40 | ) 41 | 42 | // XtCounters contains packet and byte counters. 43 | type XtCounters struct { 44 | // Pcnt is the packet counter. 45 | Pcnt uint64 46 | // Bcnt is the byte counter. 47 | Bcnt uint64 48 | } 49 | 50 | // Not is a shortand for rule negation description. 51 | type Not bool 52 | 53 | // String returns '!' for a negated rule. 54 | func (n Not) String() string { 55 | if n { 56 | return "!" 57 | } 58 | return " " 59 | } 60 | 61 | // Rule is a complete iptables rule descriptor. 62 | type Rule struct { 63 | Src *net.IPNet 64 | Dest *net.IPNet 65 | InDev string 66 | OutDev string 67 | Not struct { 68 | Src Not 69 | Dest Not 70 | InDev Not 71 | OutDev Not 72 | } 73 | Target string 74 | XtCounters 75 | } 76 | 77 | // String returns a human-readable description of a rule. 78 | func (r Rule) String() string { 79 | return fmt.Sprintf("in: %s%s, out: %s%s, %s%s -> %s%s -> %s: %d packets, %d bytes", 80 | r.Not.InDev, r.InDev, 81 | r.Not.OutDev, r.OutDev, 82 | r.Not.Src, r.Src, 83 | r.Not.Dest, r.Dest, 84 | r.Target, 85 | r.Pcnt, r.Bcnt) 86 | } 87 | 88 | // RelayedFunc is a function that returns false if there is an 'errno' to query about. Used internally to perform all lib*iptc calls serially. 89 | type RelayedFunc func() bool 90 | 91 | // ErrorFunc generates an error based on a libip*tc_strerror call. Used internally to report about errors. 92 | type ErrorFunc func() string 93 | 94 | // RelayedCall 95 | type RelayedCall struct { 96 | // Context is the C function being called. 97 | Context string 98 | // Func is the function that performs the wrapper around the C function call that does the conversion of input/output parameters. 99 | Func RelayedFunc 100 | // Error is the specific ErrorFunc needed to extract an error after the C call. 101 | Error ErrorFunc 102 | } 103 | 104 | var ( 105 | callResult = make(chan error) 106 | queueOfCalls = make(chan RelayedCall) 107 | ) 108 | 109 | func init() { 110 | // start a main loop that will process (serially) all incoming libiptc/libip6tc calls 111 | go func() { 112 | runtime.LockOSThread() 113 | 114 | for { 115 | call := <-queueOfCalls 116 | 117 | // as extra good measure, reset errno before C-land calls 118 | C.reset_errno() 119 | 120 | // libiptc logic is called here 121 | success := call.Func() 122 | 123 | var err error 124 | if !success { 125 | err = fmt.Errorf("%s: %s", call.Context, call.Error()) 126 | } 127 | 128 | // this will also signal completion of the call 129 | callResult <- err 130 | } 131 | }() 132 | } 133 | 134 | // this is used just for the errors set in xtables-lock.c: 135 | // * ENOLCK - lock was not being held at all 136 | // * EALREADY - trying to acquire lock twice 137 | // * any error set by a failed bind() call 138 | // * ETIMEOUT - could not acquire lock in specified timeout 139 | // * any error set by a failed socket() call 140 | func getNativeError() string { 141 | return C.GoString(C.strerror(C.get_errno())) 142 | } 143 | 144 | // XtablesLock acquires the same lock that a call to `iptables --wait` would. 145 | func XtablesLock(wait bool, maxSeconds uint) (result bool, osErr error) { 146 | osErr = RelayCall(func() bool { 147 | r := C.xtables_lock(true, C.uint(maxSeconds)) 148 | if r == 0 { 149 | result = true 150 | return result 151 | } else if r == 1 { 152 | result = false 153 | return result 154 | } 155 | panic("invalid return value") 156 | }, "xtables_lock", getNativeError) 157 | return 158 | } 159 | 160 | // XtablesUnlock releases an iptables lock previously acquired with XtablesLock(). 161 | func XtablesUnlock() (result bool, osErr error) { 162 | osErr = RelayCall(func() bool { 163 | r := C.xtables_unlock() 164 | if r == 0 { 165 | result = true 166 | return result 167 | } else if r == 1 { 168 | result = false 169 | return result 170 | } 171 | panic("invalid return value") 172 | }, "xtables_unlock", getNativeError) 173 | return 174 | } 175 | 176 | // GetErrno returns the OS-level errno value. It is used internally to properly report about errors. 177 | func GetErrno() int { 178 | return int(C.get_errno()) 179 | } 180 | 181 | // RelayCall will perform the C call on a OS-locked goroutine, serially. 182 | func RelayCall(f RelayedFunc, context string, e ErrorFunc) error { 183 | queueOfCalls <- RelayedCall{Func: f, Context: context, Error: e} 184 | return <-callResult 185 | } 186 | -------------------------------------------------------------------------------- /update-version.sh: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | 3 | if [ ! $# -eq 1 ]; then 4 | echo "Usage: update-version.sh 0.3.1" 1>&2 5 | exit 1 6 | fi 7 | 8 | VER="$1" 9 | 10 | sed -i "s~go-libiptc v[^ ]*~go-libiptc v${VER}~g" $(find . -type f -name '*.go' -o -name '*.c' -o -name '*.h') 11 | -------------------------------------------------------------------------------- /xtables-lock.c: -------------------------------------------------------------------------------- 1 | /* 2 | * go-libiptc v0.3.1 - libiptc bindings for Go language 3 | * Copyright (C) 2015~2016 gdm85 - https://github.com/gdm85/go-libiptc/ 4 | 5 | This program is free software; you can redistribute it and/or 6 | modify it under the terms of the GNU General Public License 7 | as published by the Free Software Foundation; either version 2 8 | of the License, or (at your option) any later version. 9 | 10 | This program is distributed in the hope that it will be useful, 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 | GNU General Public License for more details. 14 | 15 | You should have received a copy of the GNU General Public License 16 | along with this program; if not, write to the Free Software 17 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 18 | */ 19 | 20 | #include 21 | #include 22 | #include 23 | #include 24 | #include 25 | #include 26 | #include 27 | #include 28 | #include 29 | #include 30 | #include 31 | #include 32 | #include 33 | 34 | #include "xtables-lock.h" 35 | 36 | #define XT_SOCKET_NAME "xtables" 37 | #define XT_SOCKET_LEN 8 38 | 39 | int xtables_socket = -1; 40 | 41 | // it's not possible to read or write errno directly in Go 42 | void reset_errno() { 43 | errno = 0; 44 | } 45 | 46 | // some functions inconsistently report about an erroneous condition through their result, 47 | // thus error checking is peeked with this helper function 48 | // see also: https://www.securecoding.cert.org/confluence/pages/viewpage.action?pageId=6619179 49 | // NOTE: there is a PR upstream about improving error handling in iptables 50 | int get_errno() { 51 | return errno; 52 | } 53 | 54 | int xtables_unlock() { 55 | // lock was not being held at all 56 | if (xtables_socket < 0) { 57 | errno = ENOLCK; 58 | return 1; 59 | } 60 | 61 | if (close(xtables_socket) != 0) 62 | return 1; 63 | 64 | xtables_socket = -1; 65 | return 0; 66 | } 67 | 68 | // <0 - lock failed, 0 - success, 1 - failure 69 | int xtables_lock(bool wait, uint max_seconds_wait) 70 | { 71 | // trying to acquire lock twice 72 | if (xtables_socket >= 0) { 73 | errno = EALREADY; 74 | return 1; 75 | } 76 | 77 | int i = 0, ret; 78 | struct sockaddr_un xt_addr; 79 | 80 | memset(&xt_addr, 0, sizeof(xt_addr)); 81 | xt_addr.sun_family = AF_UNIX; 82 | strcpy(xt_addr.sun_path+1, XT_SOCKET_NAME); 83 | xtables_socket = socket(AF_UNIX, SOCK_STREAM, 0); 84 | /* If we can't even create a socket, fall back to prior (lockless) behavior */ 85 | if (xtables_socket < 0) { 86 | // errno is expected to have been set by previous socket() call 87 | return xtables_socket; 88 | } 89 | 90 | uint waited_seconds = 0; 91 | while (waited_seconds <= max_seconds_wait) { 92 | ret = bind(xtables_socket, (struct sockaddr*)&xt_addr, 93 | offsetof(struct sockaddr_un, sun_path)+XT_SOCKET_LEN); 94 | 95 | // successfully acquired lock (via socket) 96 | // NOTE: the socket is released with xtables_unlock(), or anyway when process exits 97 | if (ret == 0) 98 | return 0; 99 | 100 | // fail immediately 101 | if (wait == false) { 102 | // errno has been set by the bind() call 103 | return 1; 104 | } 105 | 106 | // time to wait 107 | sleep(1); 108 | ++waited_seconds; 109 | } 110 | 111 | // timeout 112 | errno = ETIMEDOUT; 113 | return 1; 114 | } 115 | -------------------------------------------------------------------------------- /xtables-lock.h: -------------------------------------------------------------------------------- 1 | /* 2 | * go-libiptc v0.3.1 - libiptc bindings for Go language 3 | * Copyright (C) 2015~2016 gdm85 - https://github.com/gdm85/go-libiptc/ 4 | 5 | This program is free software; you can redistribute it and/or 6 | modify it under the terms of the GNU General Public License 7 | as published by the Free Software Foundation; either version 2 8 | of the License, or (at your option) any later version. 9 | 10 | This program is distributed in the hope that it will be useful, 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 | GNU General Public License for more details. 14 | 15 | You should have received a copy of the GNU General Public License 16 | along with this program; if not, write to the Free Software 17 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 18 | */ 19 | 20 | // these headers needs to be here so that Go will import the externs 21 | #include 22 | #include 23 | #include 24 | 25 | int get_errno(); 26 | void reset_errno(); 27 | 28 | int xtables_lock(bool wait, uint max_seconds_wait); 29 | int xtables_unlock(); 30 | --------------------------------------------------------------------------------