add IP address ACL subsystem

git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@1123 fefdeb5f-60dc-0310-8127-8f9354f1896f

src/pulsecore/ipacl.c

@@ -0,0 +1,216 @@
+/* $Id$ */
+
+/***
+  This file is part of PulseAudio.
+ 
+  PulseAudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as
+  published by the Free Software Foundation; either version 2.1 of the
+  License, or (at your option) any later version.
+ 
+  PulseAudio is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+ 
+  You should have received a copy of the GNU Lesser General Public
+  License along with PulseAudio; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <sys/types.h>
+#include <arpa/inet.h>
+#include <string.h>
+
+#include <pulsecore/core-util.h>
+#include <pulsecore/llist.h>
+#include <pulsecore/log.h>
+#include <pulse/xmalloc.h>
+
+#include "ipacl.h"
+
+struct acl_entry {
+    PA_LLIST_FIELDS(struct acl_entry);
+    int family;    
+    struct in_addr address_ipv4;
+    struct in6_addr address_ipv6;
+    int bits;
+};
+
+struct pa_ip_acl {
+    PA_LLIST_HEAD(struct acl_entry, entries);
+};
+
+pa_ip_acl* pa_ip_acl_new(const char *s) {
+    const char *state = NULL;
+    char *a;
+    pa_ip_acl *acl;
+
+    assert(s);
+    
+    acl = pa_xnew(pa_ip_acl, 1);
+    PA_LLIST_HEAD_INIT(struct acl_entry, acl->entries);
+    
+    while ((a = pa_split(s, ";", &state))) {
+        char *slash;
+        struct acl_entry e, *n;
+        uint32_t bits;
+
+        if ((slash = strchr(a, '/'))) {
+            *slash = 0;
+            slash++;
+            if (pa_atou(slash, &bits) < 0) {
+                pa_log(__FILE__": failed to parse number of bits: %s", slash);
+                goto fail;
+            }
+        } else
+            bits = (uint32_t) -1;
+
+        if (inet_pton(AF_INET, a, &e.address_ipv4) > 0) {
+
+            e.bits = bits == (uint32_t) -1 ? 32 : (int) bits;
+            
+            if (e.bits > 32) {
+                pa_log(__FILE__": number of bits out of range: %i", e.bits);
+                goto fail;
+            }
+
+            e.family = AF_INET;
+
+            if (e.bits < 32 && (uint32_t) (ntohl(e.address_ipv4.s_addr) << e.bits) != 0)
+                pa_log_warn(__FILE__": WARNING: Host part of ACL entry '%s/%u' is not zero!", a, e.bits);
+                
+        } else if (inet_pton(AF_INET6, a, &e.address_ipv6) > 0) {
+
+            e.bits = bits == (uint32_t) -1 ? 128 : (int) bits;
+
+            if (e.bits > 128) {
+                pa_log(__FILE__": number of bits out of range: %i", e.bits);
+                goto fail;
+            }
+            e.family = AF_INET6;
+
+            if (e.bits < 128) {
+                int t = 0, i;
+
+                for (i = 0, bits = e.bits; i < 16; i++) {
+
+                    if (bits >= 8) 
+                        bits -= 8;
+                    else {
+                        if ((uint8_t) ((e.address_ipv6.s6_addr[i]) << bits) != 0) {
+                            t = 1;
+                            break;
+                        }
+                        bits = 0;
+                    }
+                }
+
+                if (t)
+                    pa_log_warn(__FILE__": WARNING: Host part of ACL entry '%s/%u' is not zero!", a, e.bits);
+            }
+            
+        } else {
+            pa_log(__FILE__": failed to parse address: %s", a);
+            goto fail;
+        }
+
+        n = pa_xmemdup(&e, sizeof(struct acl_entry));
+        PA_LLIST_PREPEND(struct acl_entry, acl->entries, n);
+        
+        pa_xfree(a);
+    }
+
+    return acl;
+    
+fail:
+    pa_xfree(a);
+    pa_ip_acl_free(acl);
+    
+    return NULL;
+}
+
+void pa_ip_acl_free(pa_ip_acl *acl) {
+    assert(acl);
+
+    while (acl->entries) {
+        struct acl_entry *e = acl->entries;
+        PA_LLIST_REMOVE(struct acl_entry, acl->entries, e);
+        pa_xfree(e);
+    }
+    
+    pa_xfree(acl);
+}
+
+int pa_ip_acl_check(pa_ip_acl *acl, int fd) {
+    struct sockaddr_storage sa;
+    struct acl_entry *e;
+    socklen_t  salen;
+        
+    assert(acl);
+    assert(fd >= 0);
+
+    salen = sizeof(sa);
+    if (getpeername(fd, (struct sockaddr*) &sa, &salen) < 0)
+        return -1;
+
+    if (sa.ss_family != AF_INET && sa.ss_family != AF_INET6)
+        return -1;
+
+    if (sa.ss_family == AF_INET && salen != sizeof(struct sockaddr_in))
+        return -1;
+
+    if (sa.ss_family == AF_INET6 && salen != sizeof(struct sockaddr_in6))
+        return -1;
+    
+    for (e = acl->entries; e; e = e->next) {
+
+        if (e->family != sa.ss_family)
+            continue;
+
+        if (e->family == AF_INET) {
+            struct sockaddr_in *sai = (struct sockaddr_in*) &sa;
+            
+            if (e->bits == 0 || /* this needs special handling because >> takes the right-hand side modulo 32 */
+                (ntohl(sai->sin_addr.s_addr ^ e->address_ipv4.s_addr) >> (32 - e->bits)) == 0)
+                return 1;
+        } else if (e->family == AF_INET6) {
+            int i, bits ;
+            struct sockaddr_in6 *sai = (struct sockaddr_in6*) &sa;
+
+            if (e->bits == 128)
+                return memcmp(&sai->sin6_addr, &e->address_ipv6, 16) == 0;
+
+            if (e->bits == 0)
+                return 1;
+                
+            for (i = 0, bits = e->bits; i < 16; i++) {
+
+                if (bits >= 8) {
+                    if (sai->sin6_addr.s6_addr[i] != e->address_ipv6.s6_addr[i])
+                        break;
+
+                    bits -= 8;
+                } else {
+                    if ((sai->sin6_addr.s6_addr[i] ^ e->address_ipv6.s6_addr[i]) >> (8 - bits) != 0)
+                        break;
+
+                    bits = 0;
+                }
+
+                if (bits == 0)
+                    return 1;
+            }
+        }
+    }
+
+    return 0;
+}

src/pulsecore/ipacl.h

@@ -0,0 +1,31 @@
+#ifndef fooparseaddrhfoo
+#define fooparseaddrhfoo
+
+/* $Id$ */
+
+/***
+  This file is part of PulseAudio.
+ 
+  PulseAudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as
+  published by the Free Software Foundation; either version 2.1 of the
+  License, or (at your option) any later version.
+ 
+  PulseAudio is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+ 
+  You should have received a copy of the GNU Lesser General Public
+  License along with PulseAudio; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+typedef struct pa_ip_acl pa_ip_acl;
+
+pa_ip_acl* pa_ip_acl_new(const char *s);
+void pa_ip_acl_free(pa_ip_acl *acl);
+int pa_ip_acl_check(pa_ip_acl *acl, int fd);
+
+#endif