Use a Ragel-generated DFA parser for ifchd command dispatch.

ifchd/CMakeLists.txt

@@ -2,7 +2,19 @@ project (ifchd)
 
 cmake_minimum_required (VERSION 2.6)
 
+set(RAGEL_IFCHD_PARSE ${CMAKE_CURRENT_BINARY_DIR}/ifchd-parse.c)
+
+find_program(RAGEL ragel)
+add_custom_command(
+  OUTPUT ${RAGEL_IFCHD_PARSE}
+  COMMAND ${RAGEL} -G2 -o ${RAGEL_IFCHD_PARSE} ifchd-parse.rl
+  DEPENDS ifchd-parse.rl
+  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+  COMMENT "Compiling Ragel state machine: ifchd-parse.rl"
+  VERBATIM
+  )
+
 file(GLOB IFCHD_SRCS "*.c")
 
-add_executable(ifchd ${IFCHD_SRCS})
+add_executable(ifchd ${RAGEL_IFCHD_PARSE} ${IFCHD_SRCS})
 target_link_libraries(ifchd ncmlib)

ifchd/ifchd-defines.h

@@ -10,6 +10,24 @@
 #define CONN_TIMEOUT 60
 #define MAX_IFACES 10
 
+enum ifchd_states {
+    STATE_NOTHING,
+    STATE_INTERFACE,
+    STATE_IP,
+    STATE_SUBNET,
+    STATE_TIMEZONE,
+    STATE_ROUTER,
+    STATE_DNS,
+    STATE_LPRSVR,
+    STATE_HOSTNAME,
+    STATE_DOMAIN,
+    STATE_IPTTL,
+    STATE_MTU,
+    STATE_BROADCAST,
+    STATE_NTPSVR,
+    STATE_WINS
+};
+
 #include <net/if.h>
 struct ifchd_client {
     /* Socket fd, current state, and idle time for connection. */
@@ -26,5 +44,14 @@ struct ifchd_client {
     char domains[MAX_BUF];
 };
 
+extern void perform_timezone(struct ifchd_client *cl, const char *str, size_t len);
+extern void perform_dns(struct ifchd_client *cl, const char *str, size_t len);
+extern void perform_lprsvr(struct ifchd_client *cl, const char *str, size_t len);
+extern void perform_hostname(struct ifchd_client *cl, const char *str, size_t len);
+extern void perform_domain(struct ifchd_client *cl, const char *str, size_t len);
+extern void perform_ipttl(struct ifchd_client *cl, const char *str, size_t len);
+extern void perform_ntpsrv(struct ifchd_client *cl, const char *str, size_t len);
+extern void perform_wins(struct ifchd_client *cl, const char *str, size_t len);
+
 #endif /* IFCHD_DEFINES_H_ */
 

ifchd/ifchd-parse.rl

@@ -0,0 +1,151 @@
+/* ifchd-parse.rl - interface change daemon parser
+ *
+ * Copyright (c) 2004-2013 Nicholas J. Kain <njkain at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stddef.h>
+#include <string.h>
+
+#include "ifchd-defines.h"
+#include "log.h"
+#include "ifch_proto.h"
+#include "strl.h"
+#include "linux.h"
+
+%%{
+    machine ifchd_parser;
+
+    action Reset { cl->state = STATE_NOTHING; }
+    action ArgSt { arg_start = p; }
+    action ArgEn {
+        arg_len = p - arg_start;
+        if (arg_len > sizeof tb - 1) {
+            log_line("command argument would overflow");
+            return -1;
+        }
+        memcpy(tb, arg_start, arg_len);
+        tb[arg_len] = 0;
+    }
+
+    action Dispatch {
+        switch (cl->state) {
+        case STATE_INTERFACE: perform_interface(cl, tb, arg_len); break;
+        case STATE_IP: perform_ip(cl, tb, arg_len); break;
+        case STATE_SUBNET: perform_subnet(cl, tb, arg_len); break;
+        case STATE_TIMEZONE: perform_timezone(cl, tb, arg_len); break;
+        case STATE_ROUTER: perform_router(cl, tb, arg_len); break;
+        case STATE_DNS: perform_dns(cl, tb, arg_len); break;
+        case STATE_LPRSVR: perform_lprsvr(cl, tb, arg_len); break;
+        case STATE_HOSTNAME: perform_hostname(cl, tb, arg_len); break;
+        case STATE_DOMAIN: perform_domain(cl, tb, arg_len); break;
+        case STATE_IPTTL: perform_ipttl(cl, tb, arg_len); break;
+        case STATE_MTU: perform_mtu(cl, tb, arg_len); break;
+        case STATE_BROADCAST: perform_broadcast(cl, tb, arg_len); break;
+        case STATE_NTPSVR: perform_ntpsrv(cl, tb, arg_len); break;
+        case STATE_WINS: perform_wins(cl, tb, arg_len); break;
+        default:
+            log_line("error: invalid state in dispatch_work");
+            return -1;
+        }
+    }
+
+    interface = 'iface';
+    ip = 'ip';
+    subnet = 'snet';
+    dns = 'dns';
+    lprsvr = 'lpr';
+    ntpsvr = 'ntp';
+    wins = 'wins';
+    router = 'routr';
+    broadcast = 'bcast';
+    timezone = 'tzone';
+    hostname = 'host';
+    domain = 'dom';
+    ipttl = 'ipttl';
+    mtu = 'mtu';
+
+    cmdname = (interface % { cl->state = STATE_INTERFACE; }
+              |ip % { cl->state = STATE_IP; }
+              |subnet % { cl->state = STATE_SUBNET; }
+              |dns % { cl->state = STATE_DNS; }
+              |lprsvr % { cl->state = STATE_LPRSVR; }
+              |ntpsvr % { cl->state = STATE_NTPSVR; }
+              |wins % { cl->state = STATE_WINS; }
+              |router % { cl->state = STATE_ROUTER; }
+              |broadcast % { cl->state = STATE_BROADCAST; }
+              |timezone % { cl->state = STATE_TIMEZONE; }
+              |hostname % { cl->state = STATE_HOSTNAME; }
+              |domain % { cl->state = STATE_DOMAIN; }
+              |ipttl % { cl->state = STATE_IPTTL; }
+              |mtu % { cl->state = STATE_MTU; }
+              );
+
+    command = cmdname ':' ([^;\0]+ > ArgSt % ArgEn) (';' > Dispatch);
+    main := (command > Reset)+;
+}%%
+
+%% write data;
+
+/*
+ * Returns -1 on fatal error; that leads to peer connection being closed.
+ */
+int execute_buffer(struct ifchd_client *cl, char *newbuf)
+{
+    char buf[MAX_BUF * 2];
+    char tb[MAX_BUF];
+
+    if (strnkcpy(buf, cl->ibuf, sizeof buf))
+        goto buftooshort;
+    if (strnkcat(buf, newbuf, sizeof buf)) {
+buftooshort:
+        log_line("error: input is too long for buffer");
+        return -1;
+    }
+
+    size_t init_siz = strlen(buf);
+    const char *p = buf;
+    const char *pe = p + init_siz;
+    const char *arg_start;
+    size_t arg_len;
+    unsigned int cs = 0;
+
+    %% write init;
+    %% write exec;
+
+    size_t bytes_left = pe - p;
+    if (bytes_left > 0) {
+        size_t taken = init_siz - bytes_left;
+        strnkcpy(cl->ibuf, buf + taken, MAX_BUF);
+    }
+
+    if (cs < ifchd_parser_first_final) {
+        log_line("error: received invalid commands");
+        return -1;
+    }
+    log_line("Commands received and successfully executed.");
+    return 0;
+}
+

ifchd/ifchd.c

@@ -1,6 +1,6 @@
 /* ifchd.c - interface change daemon
  *
- * Copyright (c) 2004-2012 Nicholas J. Kain <njkain at gmail dot com>
+ * Copyright (c) 2004-2013 Nicholas J. Kain <njkain at gmail dot com>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -60,24 +60,6 @@
 #include "linux.h"
 #include "seccomp-bpf.h"
 
-enum states {
-    STATE_NOTHING,
-    STATE_INTERFACE,
-    STATE_IP,
-    STATE_SUBNET,
-    STATE_TIMEZONE,
-    STATE_ROUTER,
-    STATE_DNS,
-    STATE_LPRSVR,
-    STATE_HOSTNAME,
-    STATE_DOMAIN,
-    STATE_IPTTL,
-    STATE_MTU,
-    STATE_BROADCAST,
-    STATE_NTPSVR,
-    STATE_WINS
-};
-
 struct ifchd_client clients[SOCK_QUEUE];
 
 static int epollfd, signalFd;
@@ -96,6 +78,8 @@ static pid_t peer_pid;
 
 static int gflags_verbose = 0;
 
+extern int execute_buffer(struct ifchd_client *cl, char *newbuf);
+
 static void writeordie(int fd, const char *buf, int len)
 {
     if (safe_write(fd, buf, len) == -1)
@@ -240,7 +224,7 @@ static void write_resolve_conf(struct ifchd_client *cl)
 
     off = lseek(resolv_conf_fd, 0, SEEK_CUR);
     if (off == -1) {
-        log_line("write_resolve_conf: lseek returned error: %s\n",
+        log_line("write_resolve_conf: lseek returned error: %s",
                 strerror(errno));
         return;
     }
@@ -249,64 +233,64 @@ static void write_resolve_conf(struct ifchd_client *cl)
     if (r == -1) {
         if (errno == EINTR)
             goto retry;
-        log_line("write_resolve_conf: ftruncate returned error: %s\n",
+        log_line("write_resolve_conf: ftruncate returned error: %s",
                  strerror(errno));
         return;
     }
     r = fsync(resolv_conf_fd);
     if (r == -1) {
-        log_line("write_resolve_conf: fsync returned error: %s\n",
+        log_line("write_resolve_conf: fsync returned error: %s",
                  strerror(errno));
         return;
     }
 }
 
 /* XXX: addme */
-static void perform_timezone(struct ifchd_client *cl, char *str)
+void perform_timezone(struct ifchd_client *cl, const char *str, size_t len)
 {}
 
 /* Add a dns server to the /etc/resolv.conf -- we already have a fd. */
-static void perform_dns(struct ifchd_client *cl, char *str)
+void perform_dns(struct ifchd_client *cl, const char *str, size_t len)
 {
     if (!str || resolv_conf_fd == -1)
         return;
-    strnkcpy(cl->namesvrs, str, MAX_BUF);
+    strnkcpy(cl->namesvrs, str, sizeof cl->namesvrs);
     write_resolve_conf(cl);
 }
 
 /* Updates for print daemons are too non-standard to be useful. */
-static void perform_lprsvr(struct ifchd_client *cl, char *str)
+void perform_lprsvr(struct ifchd_client *cl, const char *str, size_t len)
 {}
 
 /* Sets machine hostname. */
-static void perform_hostname(struct ifchd_client *cl, char *str)
+void perform_hostname(struct ifchd_client *cl, const char *str, size_t len)
 {
     if (!allow_hostname || !str)
         return;
     if (sethostname(str, strlen(str) + 1) == -1)
-        log_line("sethostname returned %s\n", strerror(errno));
+        log_line("sethostname returned %s", strerror(errno));
 }
 
 /* update "domain" and "search" in /etc/resolv.conf */
-static void perform_domain(struct ifchd_client *cl, char *str)
+void perform_domain(struct ifchd_client *cl, const char *str, size_t len)
 {
     if (!str || resolv_conf_fd == -1)
         return;
-    strnkcpy(cl->domains, str, MAX_BUF);
+    strnkcpy(cl->domains, str, sizeof cl->domains);
     write_resolve_conf(cl);
 }
 
 /* I don't think this can be done without a netfilter extension
  * that isn't in the mainline kernels. */
-static void perform_ipttl(struct ifchd_client *cl, char *str)
+void perform_ipttl(struct ifchd_client *cl, const char *str, size_t len)
 {}
 
 /* XXX: addme */
-static void perform_ntpsrv(struct ifchd_client *cl, char *str)
+void perform_ntpsrv(struct ifchd_client *cl, const char *str, size_t len)
 {}
 
 /* Maybe Samba cares about this feature?  I don't know. */
-static void perform_wins(struct ifchd_client *cl, char *str)
+void perform_wins(struct ifchd_client *cl, const char *str, size_t len)
 {}
 
 static inline void clock_or_die(struct timespec *ts)
@@ -378,165 +362,6 @@ static void close_idle_sk(void)
     }
 }
 
-/*
- * Returns -1 on fatal error.
- */
-static int execute_buffer(struct ifchd_client *cl, char *newbuf)
-{
-    char buf[MAX_BUF * 2];
-    char *p = buf, *endp;
-
-    memset(buf, 0, sizeof buf);
-    if (strnkcat(buf, cl->ibuf, sizeof buf))
-        goto buftooshort;
-    if (strnkcat(buf, newbuf, sizeof buf)) {
-buftooshort:
-        log_line("error: input is too long for buffer");
-        return -1;
-    }
-
-    for (endp = p;;p = endp) {
-        if (cl->state == STATE_NOTHING) {
-            char *colon = strchr(p, ':');
-            if (!colon)
-                break;
-            char *semi = strchr(p, ';');
-            if (semi && semi < colon) {
-                log_line("bad syntax: STATE_NOTHING and a ';' came before ':'");
-                return -1;
-            }
-            *colon = '\0';
-            endp = colon + 1;
-        } else {
-            char *semi = strchr(p, ';');
-            if (!semi)
-                break;
-            char *colon = strchr(p, ':');
-            if (colon && colon < semi) {
-                log_line("bad syntax: !STATE_NOTHING and a ':' came before ';'");
-                return -1;
-            }
-            *semi = '\0';
-            endp = semi + 1;
-        }
-
-        if (!strlen(p))
-            continue;
-
-        switch (cl->state) {
-            case STATE_NOTHING:
-                if (strncmp(p, CMD_INTERFACE, sizeof(CMD_INTERFACE)) == 0)
-                    cl->state = STATE_INTERFACE;
-                if (strncmp(p, CMD_IP, sizeof(CMD_IP)) == 0)
-                    cl->state = STATE_IP;
-                if (strncmp(p, CMD_SUBNET, sizeof(CMD_SUBNET)) == 0)
-                    cl->state = STATE_SUBNET;
-                if (strncmp(p, CMD_TIMEZONE, sizeof(CMD_TIMEZONE)) == 0)
-                    cl->state = STATE_TIMEZONE;
-                if (strncmp(p, CMD_ROUTER, sizeof(CMD_ROUTER)) == 0)
-                    cl->state = STATE_ROUTER;
-                if (strncmp(p, CMD_DNS, sizeof(CMD_DNS)) == 0)
-                    cl->state = STATE_DNS;
-                if (strncmp(p, CMD_LPRSVR, sizeof(CMD_LPRSVR)) == 0)
-                    cl->state = STATE_LPRSVR;
-                if (strncmp(p, CMD_HOSTNAME, sizeof(CMD_HOSTNAME)) == 0)
-                    cl->state = STATE_HOSTNAME;
-                if (strncmp(p, CMD_DOMAIN, sizeof(CMD_DOMAIN)) == 0)
-                    cl->state = STATE_DOMAIN;
-                if (strncmp(p, CMD_IPTTL, sizeof(CMD_IPTTL)) == 0)
-                    cl->state = STATE_IPTTL;
-                if (strncmp(p, CMD_MTU, sizeof(CMD_MTU)) == 0)
-                    cl->state = STATE_MTU;
-                if (strncmp(p, CMD_BROADCAST, sizeof(CMD_BROADCAST)) == 0)
-                    cl->state = STATE_BROADCAST;
-                if (strncmp(p, CMD_NTPSVR, sizeof(CMD_NTPSVR)) == 0)
-                    cl->state = STATE_NTPSVR;
-                if (strncmp(p, CMD_WINS, sizeof(CMD_WINS)) == 0)
-                    cl->state = STATE_WINS;
-                break;
-
-            case STATE_INTERFACE:
-                perform_interface(cl, p);
-                cl->state = STATE_NOTHING;
-                break;
-
-            case STATE_IP:
-                perform_ip(cl, p);
-                cl->state = STATE_NOTHING;
-                break;
-
-            case STATE_SUBNET:
-                perform_subnet(cl, p);
-                cl->state = STATE_NOTHING;
-                break;
-
-            case STATE_TIMEZONE:
-                perform_timezone(cl, p);
-                cl->state = STATE_NOTHING;
-                break;
-
-            case STATE_ROUTER:
-                perform_router(cl, p);
-                cl->state = STATE_NOTHING;
-                break;
-
-            case STATE_DNS:
-                perform_dns(cl, p);
-                cl->state = STATE_NOTHING;
-                break;
-
-            case STATE_LPRSVR:
-                perform_lprsvr(cl, p);
-                cl->state = STATE_NOTHING;
-                break;
-
-            case STATE_HOSTNAME:
-                perform_hostname(cl, p);
-                cl->state = STATE_NOTHING;
-                break;
-
-            case STATE_DOMAIN:
-                perform_domain(cl, p);
-                cl->state = STATE_NOTHING;
-                break;
-
-            case STATE_IPTTL:
-                perform_ipttl(cl, p);
-                cl->state = STATE_NOTHING;
-                break;
-
-            case STATE_MTU:
-                perform_mtu(cl, p);
-                cl->state = STATE_NOTHING;
-                break;
-
-            case STATE_BROADCAST:
-                perform_broadcast(cl, p);
-                cl->state = STATE_NOTHING;
-                break;
-
-            case STATE_NTPSVR:
-                perform_ntpsrv(cl, p);
-                cl->state = STATE_NOTHING;
-                break;
-
-            case STATE_WINS:
-                perform_wins(cl, p);
-                cl->state = STATE_NOTHING;
-                break;
-
-            default:
-                log_line("warning: invalid state in dispatch_work\n");
-                break;
-        }
-    }
-    size_t remsize = strlen(endp);
-    if (remsize > MAX_BUF - 1)
-        return -1;
-    strnkcpy(cl->ibuf, endp, MAX_BUF);
-    return 0;
-}
-
 /* Opens a non-blocking listening socket with the appropriate properties. */
 static int get_listen(void)
 {
@@ -600,7 +425,7 @@ static void accept_conns(int *lsock)
             case EBADF:
             case ENOTSOCK:
             case EINVAL:
-                log_line("warning: accept returned %s!\n", strerror(errno));
+                log_line("warning: accept returned %s!", strerror(errno));
 
                 epoll_del(*lsock);
                 close(*lsock);
@@ -612,11 +437,11 @@ static void accept_conns(int *lsock)
             case ECONNABORTED:
             case EMFILE:
             case ENFILE:
-                log_line("warning: accept returned %s!\n", strerror(errno));
+                log_line("warning: accept returned %s!", strerror(errno));
                 return;
 
             default:
-                log_line("warning: accept returned a mysterious error: %s\n",
+                log_line("warning: accept returned a mysterious error: %s",
                         strerror(errno));
                 return;
         }
@@ -811,7 +636,7 @@ int main(int argc, char** argv) {
 
             case 'v':
                 printf("ifchd %s, if change daemon.\n", IFCHD_VERSION);
-                printf("Copyright (c) 2004-2012 Nicholas J. Kain\n"
+                printf("Copyright (c) 2004-2013 Nicholas J. Kain\n"
                        "All rights reserved.\n\n"
                        "Redistribution and use in source and binary forms, with or without\n"
                        "modification, are permitted provided that the following conditions are met:\n\n"

ifchd/linux.c

@@ -1,6 +1,6 @@
 /* linux.c - ifchd Linux-specific functions
  *
- * Copyright (c) 2004-2012 Nicholas J. Kain <njkain at gmail dot com>
+ * Copyright (c) 2004-2013 Nicholas J. Kain <njkain at gmail dot com>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -76,7 +76,7 @@ static int is_permitted(char *name)
         if (strcmp(name, okif[i]) == 0)
             return 1;
     }
-    log_line("attempt to modify interface %s denied\n", name);
+    log_line("attempt to modify interface %s denied", name);
     return 0;
 }
 
@@ -99,11 +99,11 @@ int authorized_peer(int sk, pid_t pid, uid_t uid, gid_t gid)
             (gid == 0 || cr.gid == gid))
             ret = 1;
     } else
-        log_line("getsockopt returned an error: %s\n", strerror(errno));
+        log_line("getsockopt returned an error: %s", strerror(errno));
     return ret;
 }
 
-void perform_interface(struct ifchd_client *cl, char *str)
+void perform_interface(struct ifchd_client *cl, const char *str, size_t len)
 {
     if (!str)
         return;
@@ -123,21 +123,21 @@ static int set_if_flag(struct ifchd_client *cl, short flag)
 
     fd = socket(AF_INET, SOCK_DGRAM, 0);
     if (fd == -1) {
-        log_line("%s: (set_if_flag) failed to open interface socket: %s\n",
+        log_line("%s: (set_if_flag) failed to open interface socket: %s",
 		 cl->ifnam, strerror(errno));
         goto out0;
     }
 
     strnkcpy(ifrt.ifr_name, cl->ifnam, IFNAMSIZ);
     if (ioctl(fd, SIOCGIFFLAGS, &ifrt) < 0) {
-        log_line("%s: unknown interface: %s\n", cl->ifnam, strerror(errno));
+        log_line("%s: unknown interface: %s", cl->ifnam, strerror(errno));
         goto out1;
     }
     if (((ifrt.ifr_flags & flag ) ^ flag) & flag) {
         strnkcpy(ifrt.ifr_name, cl->ifnam, IFNAMSIZ);
         ifrt.ifr_flags |= flag;
         if (ioctl(fd, SIOCSIFFLAGS, &ifrt) < 0) {
-            log_line("%s: failed to set interface flags: %s\n",
+            log_line("%s: failed to set interface flags: %s",
                      cl->ifnam, strerror(errno));
             goto out1;
         }
@@ -151,7 +151,7 @@ static int set_if_flag(struct ifchd_client *cl, short flag)
 }
 
 /* Sets IP address on an interface and brings it up. */
-void perform_ip(struct ifchd_client *cl, char *str)
+void perform_ip(struct ifchd_client *cl, const char *str, size_t len)
 {
     int fd;
     struct in_addr ipaddr;
@@ -175,18 +175,18 @@ void perform_ip(struct ifchd_client *cl, char *str)
 
     fd = socket(AF_INET, SOCK_DGRAM, 0);
     if (fd == -1) {
-        log_line("%s: (perform_ip) failed to open interface socket: %s\n",
+        log_line("%s: (perform_ip) failed to open interface socket: %s",
 		 cl->ifnam, strerror(errno));
         return;
     }
     if (ioctl(fd, SIOCSIFADDR, &ifrt) < 0)
-        log_line("%s: failed to configure IP: %s\n",
+        log_line("%s: failed to configure IP: %s",
 		 cl->ifnam, strerror(errno));
     close(fd);
 }
 
 /* Sets the subnet mask on an interface. */
-void perform_subnet(struct ifchd_client *cl, char *str)
+void perform_subnet(struct ifchd_client *cl, const char *str, size_t len)
 {
     int fd;
     struct in_addr subnet;
@@ -208,20 +208,20 @@ void perform_subnet(struct ifchd_client *cl, char *str)
 
     fd = socket(AF_INET, SOCK_DGRAM, 0);
     if (fd == -1) {
-        log_line("%s: (perform_ip) failed to open interface socket: %s\n",
+        log_line("%s: (perform_ip) failed to open interface socket: %s",
 		 cl->ifnam, strerror(errno));
         return;
     }
     if (ioctl(fd, SIOCSIFNETMASK, &ifrt) < 0) {
         sin.sin_addr.s_addr = 0xffffffff;
         if (ioctl(fd, SIOCSIFNETMASK, &ifrt) < 0)
-            log_line("%s: failed to configure subnet: %s\n",
+            log_line("%s: failed to configure subnet: %s",
 		     cl->ifnam, strerror(errno));
     }
     close(fd);
 }
 
-void perform_router(struct ifchd_client *cl, char *str)
+void perform_router(struct ifchd_client *cl, const char *str, size_t len)
 {
     struct rtentry rt;
     struct sockaddr_in *dest;
@@ -255,19 +255,19 @@ void perform_router(struct ifchd_client *cl, char *str)
 
     fd = socket(AF_INET, SOCK_DGRAM, 0);
     if (fd == -1) {
-        log_line("%s: (perform_router) failed to open interface socket: %s\n",
+        log_line("%s: (perform_router) failed to open interface socket: %s",
 		 cl->ifnam, strerror(errno));
         return;
     }
     if (ioctl(fd, SIOCADDRT, &rt)) {
         if (errno != EEXIST)
-            log_line("%s: failed to set route: %s\n",
+            log_line("%s: failed to set route: %s",
                      cl->ifnam, strerror(errno));
     }
     close(fd);
 }
 
-void perform_mtu(struct ifchd_client *cl, char *str)
+void perform_mtu(struct ifchd_client *cl, const char *str, size_t len)
 {
     int fd;
     unsigned int mtu;
@@ -287,17 +287,17 @@ void perform_mtu(struct ifchd_client *cl, char *str)
 
     fd = socket(AF_INET, SOCK_DGRAM, 0);
     if (fd == -1) {
-        log_line("%s: (perform_mtu) failed to open interface socket: %s\n",
+        log_line("%s: (perform_mtu) failed to open interface socket: %s",
 		 cl->ifnam, strerror(errno));
         return;
     }
     if (ioctl(fd, SIOCSIFMTU, &ifrt) < 0)
-        log_line("%s: failed to set MTU (%d): %s\n", cl->ifnam, mtu,
+        log_line("%s: failed to set MTU (%d): %s", cl->ifnam, mtu,
 		 strerror(errno));
     close(fd);
 }
 
-void perform_broadcast(struct ifchd_client *cl, char *str)
+void perform_broadcast(struct ifchd_client *cl, const char *str, size_t len)
 {
     int fd;
     struct in_addr broadcast;
@@ -319,11 +319,11 @@ void perform_broadcast(struct ifchd_client *cl, char *str)
 
     fd = socket(AF_INET, SOCK_DGRAM, 0);
     if (fd == -1) {
-        log_line("%s: (perform_broadcast) failed to open interface socket: %s\n", cl->ifnam, strerror(errno));
+        log_line("%s: (perform_broadcast) failed to open interface socket: %s", cl->ifnam, strerror(errno));
         return;
     }
     if (ioctl(fd, SIOCSIFBRDADDR, &ifrt) < 0)
-        log_line("%s: failed to set broadcast: %s\n",
+        log_line("%s: failed to set broadcast: %s",
 		 cl->ifnam, strerror(errno));
     close(fd);
 }

ifchd/linux.h

@@ -32,11 +32,11 @@ void clear_if_data(struct ifchd_client *cl);
 void initialize_if_data(void);
 void add_permitted_if(char *s);
 int authorized_peer(int sk, pid_t pid, uid_t uid, gid_t gid);
-void perform_interface(struct ifchd_client *cl, char *str);
+void perform_interface(struct ifchd_client *cl, const char *str, size_t len);
-void perform_ip(struct ifchd_client *cl, char *str);
+void perform_ip(struct ifchd_client *cl, const char *str, size_t len);
-void perform_subnet(struct ifchd_client *cl, char *str);
+void perform_subnet(struct ifchd_client *cl, const char *str, size_t len);
-void perform_router(struct ifchd_client *cl, char *str);
+void perform_router(struct ifchd_client *cl, const char *str, size_t len);
-void perform_mtu(struct ifchd_client *cl, char *str);
+void perform_mtu(struct ifchd_client *cl, const char *str, size_t len);
-void perform_broadcast(struct ifchd_client *cl, char *str);
+void perform_broadcast(struct ifchd_client *cl, const char *str, size_t len);
 #endif