iptables: add optional [seconds] argument to -w

This patch adds an optional numeric argument
to -w option (added with 93587a0) so one can
specify how long to wait for an exclusive lock.

If the value isn't specified it works as before,
i.e. program waits indefinitely.

If user specifies it, program exits after
the given time interval passes.

This patch also adds the -w/--wait to nftables
compat code, so the parser doesn't complain.

[ In the original patch, iptables-compat -w X was not working,
  I have fixed by adding the dummy code not to break scripts
  using the new optional argument --pablo ]

Signed-off-by: Jiri Popelka <jpopelka@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/iptables/ip6tables.c b/iptables/ip6tables.c
index 2ebfd6c0ecd416af5141652828715cc76e8afd37..8db13b45e7c5d219471fba37d5cdb51e77ef038f 100644 (file)
--- a/iptables/ip6tables.c
+++ b/iptables/ip6tables.c
@@ -102,7 +102,7 @@ static struct option original_opts[] = {
        {.name = "numeric",       .has_arg = 0, .val = 'n'},
        {.name = "out-interface", .has_arg = 1, .val = 'o'},
        {.name = "verbose",       .has_arg = 0, .val = 'v'},
-       {.name = "wait",          .has_arg = 0, .val = 'w'},
+       {.name = "wait",          .has_arg = 2, .val = 'w'},
        {.name = "exact",         .has_arg = 0, .val = 'x'},
        {.name = "version",       .has_arg = 0, .val = 'V'},
        {.name = "help",          .has_arg = 2, .val = 'h'},
@@ -259,7 +259,7 @@ exit_printhelp(const struct xtables_rule_match *matches)
 "                              network interface name ([+] for wildcard)\n"
 "  --table     -t table        table to manipulate (default: `filter')\n"
 "  --verbose   -v              verbose mode\n"
-"  --wait      -w              wait for the xtables lock\n"
+"  --wait      -w [seconds]    wait for the xtables lock\n"
 "  --line-numbers              print line numbers when listing\n"
 "  --exact     -x              expand numbers (display exact values)\n"
 /*"[!] --fragment      -f              match second or further fragments only\n"*/
@@ -1323,7 +1323,7 @@ int do_command6(int argc, char *argv[], char **table,
        struct in6_addr *smasks = NULL, *dmasks = NULL;
 
        int verbose = 0;
-       bool wait = false;
+       int wait = 0;
        const char *chain = NULL;
        const char *shostnetworkmask = NULL, *dhostnetworkmask = NULL;
        const char *policy = NULL, *newname = NULL;
@@ -1359,7 +1359,7 @@ int do_command6(int argc, char *argv[], char **table,
 
        opts = xt_params->orig_opts;
        while ((cs.c = getopt_long(argc, argv,
-          "-:A:C:D:R:I:L::S::M:F::Z::N:X::E:P:Vh::o:p:s:d:j:i:bvwnt:m:xc:g:46",
+          "-:A:C:D:R:I:L::S::M:F::Z::N:X::E:P:Vh::o:p:s:d:j:i:bvw::nt:m:xc:g:46",
                                           opts, NULL)) != -1) {
                switch (cs.c) {
                        /*
@@ -1603,7 +1603,16 @@ int do_command6(int argc, char *argv[], char **table,
                                              "You cannot use `-w' from "
                                              "ip6tables-restore");
                        }
-                       wait = true;
+                       wait = -1;
+                       if (optarg) {
+                               if (sscanf(optarg, "%i", &wait) != 1)
+                                       xtables_error(PARAMETER_PROBLEM,
+                                               "wait seconds not numeric");
+                       } else if (optind < argc && argv[optind][0] != '-'
+                                                && argv[optind][0] != '!')
+                               if (sscanf(argv[optind++], "%i", &wait) != 1)
+                                       xtables_error(PARAMETER_PROBLEM,
+                                               "wait seconds not numeric");
                        break;
 
                case 'm':
@@ -1754,8 +1763,11 @@ int do_command6(int argc, char *argv[], char **table,
 
        /* Attempt to acquire the xtables lock */
        if (!restore && !xtables_lock(wait)) {
-               fprintf(stderr, "Another app is currently holding the xtables lock. "
-                       "Perhaps you want to use the -w option?\n");
+               fprintf(stderr, "Another app is currently holding the xtables lock. ");
+               if (wait == 0)
+                       fprintf(stderr, "Perhaps you want to use the -w option?\n");
+               else
+                       fprintf(stderr, "Stopped waiting after %ds.\n", wait);
                xtables_free_opts(1);
                exit(RESOURCE_PROBLEM);
        }

diff --git a/iptables/iptables.8.in b/iptables/iptables.8.in
index 8ef222e56ef27aa781e00506beb4dcc1a1008aa9..ceba5dc240b8c3f5409a73d245f9b6fdc57dbbc5 100644 (file)
--- a/iptables/iptables.8.in
+++ b/iptables/iptables.8.in
@@ -359,12 +359,13 @@ For appending, insertion, deletion and replacement, this causes
 detailed information on the rule or rules to be printed. \fB\-v\fP may be
 specified multiple times to possibly emit more detailed debug statements.
 .TP
-\fB\-w\fP, \fB\-\-wait\fP
+\fB\-w\fP, \fB\-\-wait\fP [\fIseconds\fP]
 Wait for the xtables lock.
 To prevent multiple instances of the program from running concurrently,
 an attempt will be made to obtain an exclusive lock at launch.  By default,
 the program will exit if the lock cannot be obtained.  This option will
-make the program wait until the exclusive lock can be obtained.
+make the program wait (indefinitely or for optional \fIseconds\fP) until
+the exclusive lock can be obtained.
 .TP
 \fB\-n\fP, \fB\-\-numeric\fP
 Numeric output.

diff --git a/iptables/iptables.c b/iptables/iptables.c
index 471bff0640ea9d4e5b8bf1f38221feffcaa202db..88953c476a89e117cfec1b480ad1f51409b583c4 100644 (file)
--- a/iptables/iptables.c
+++ b/iptables/iptables.c
@@ -99,7 +99,7 @@ static struct option original_opts[] = {
        {.name = "numeric",       .has_arg = 0, .val = 'n'},
        {.name = "out-interface", .has_arg = 1, .val = 'o'},
        {.name = "verbose",       .has_arg = 0, .val = 'v'},
-       {.name = "wait",          .has_arg = 0, .val = 'w'},
+       {.name = "wait",          .has_arg = 2, .val = 'w'},
        {.name = "exact",         .has_arg = 0, .val = 'x'},
        {.name = "fragments",     .has_arg = 0, .val = 'f'},
        {.name = "version",       .has_arg = 0, .val = 'V'},
@@ -253,7 +253,7 @@ exit_printhelp(const struct xtables_rule_match *matches)
 "                              network interface name ([+] for wildcard)\n"
 "  --table     -t table        table to manipulate (default: `filter')\n"
 "  --verbose   -v              verbose mode\n"
-"  --wait      -w              wait for the xtables lock\n"
+"  --wait      -w [seconds]    wait for the xtables lock\n"
 "  --line-numbers              print line numbers when listing\n"
 "  --exact     -x              expand numbers (display exact values)\n"
 "[!] --fragment        -f              match second or further fragments only\n"
@@ -1319,7 +1319,7 @@ int do_command4(int argc, char *argv[], char **table,
        struct in_addr *daddrs = NULL, *dmasks = NULL;
 
        int verbose = 0;
-       bool wait = false;
+       int wait = 0;
        const char *chain = NULL;
        const char *shostnetworkmask = NULL, *dhostnetworkmask = NULL;
        const char *policy = NULL, *newname = NULL;
@@ -1352,10 +1352,9 @@ int do_command4(int argc, char *argv[], char **table,
        /* Suppress error messages: we may add new options if we
            demand-load a protocol. */
        opterr = 0;
-
        opts = xt_params->orig_opts;
        while ((cs.c = getopt_long(argc, argv,
-          "-:A:C:D:R:I:L::S::M:F::Z::N:X::E:P:Vh::o:p:s:d:j:i:fbvwnt:m:xc:g:46",
+          "-:A:C:D:R:I:L::S::M:F::Z::N:X::E:P:Vh::o:p:s:d:j:i:fbvw::nt:m:xc:g:46",
                                           opts, NULL)) != -1) {
                switch (cs.c) {
                        /*
@@ -1597,7 +1596,16 @@ int do_command4(int argc, char *argv[], char **table,
                                              "You cannot use `-w' from "
                                              "iptables-restore");
                        }
-                       wait = true;
+                       wait = -1;
+                       if (optarg) {
+                               if (sscanf(optarg, "%i", &wait) != 1)
+                                       xtables_error(PARAMETER_PROBLEM,
+                                               "wait seconds not numeric");
+                       } else if (optind < argc && argv[optind][0] != '-'
+                                                && argv[optind][0] != '!')
+                               if (sscanf(argv[optind++], "%i", &wait) != 1)
+                                       xtables_error(PARAMETER_PROBLEM,
+                                               "wait seconds not numeric");
                        break;
 
                case 'm':
@@ -1751,8 +1759,11 @@ int do_command4(int argc, char *argv[], char **table,
 
        /* Attempt to acquire the xtables lock */
        if (!restore && !xtables_lock(wait)) {
-               fprintf(stderr, "Another app is currently holding the xtables lock. "
-                       "Perhaps you want to use the -w option?\n");
+               fprintf(stderr, "Another app is currently holding the xtables lock. ");
+               if (wait == 0)
+                       fprintf(stderr, "Perhaps you want to use the -w option?\n");
+               else
+                       fprintf(stderr, "Stopped waiting after %ds.\n", wait);
                xtables_free_opts(1);
                exit(RESOURCE_PROBLEM);
        }

diff --git a/iptables/xshared.c b/iptables/xshared.c
index 6c9992ed8eaff067e60014ec2bf8578451d5ffd7..b18022eeba45cedcb4bb397cc7d450e14cade34e 100644 (file)
--- a/iptables/xshared.c
+++ b/iptables/xshared.c
@@ -243,10 +243,11 @@ void xs_init_match(struct xtables_match *match)
                match->init(match->m);
 }
 
-bool xtables_lock(bool wait)
+bool xtables_lock(int wait)
 {
        int i = 0, ret, xt_socket;
        struct sockaddr_un xt_addr;
+       int waited = 0;
 
        memset(&xt_addr, 0, sizeof(xt_addr));
        xt_addr.sun_family = AF_UNIX;
@@ -261,11 +262,12 @@ bool xtables_lock(bool wait)
                           offsetof(struct sockaddr_un, sun_path)+XT_SOCKET_LEN);
                if (ret == 0)
                        return true;
-               else if (wait == false)
+               else if (wait >= 0 && waited >= wait)
                        return false;
                if (++i % 2 == 0)
                        fprintf(stderr, "Another app is currently holding the xtables lock; "
-                               "waiting for it to exit...\n");
+                               "waiting (%ds) for it to exit...\n", waited);
+               waited++;
                sleep(1);
        }
 }

diff --git a/iptables/xshared.h b/iptables/xshared.h
index 27c5b786259a51806cccdb50f236b3d569bbe4bf..40dd9154f444abfe366c4eb68ab03effdbfaa4e7 100644 (file)
--- a/iptables/xshared.h
+++ b/iptables/xshared.h
@@ -85,7 +85,7 @@ extern struct xtables_match *load_proto(struct iptables_command_state *);
 extern int subcmd_main(int, char **, const struct subcommand *);
 extern void xs_init_target(struct xtables_target *);
 extern void xs_init_match(struct xtables_match *);
-extern bool xtables_lock(bool wait);
+extern bool xtables_lock(int wait);
 
 extern const struct xtables_afinfo *afinfo;
 

diff --git a/iptables/xtables.c b/iptables/xtables.c
index 45a5ac631bfd32214404e8513956e98ff4dd7075..d661dd16eccf106eecd0cf18a433a2e3bac6b4d1 100644 (file)
--- a/iptables/xtables.c
+++ b/iptables/xtables.c
@@ -85,6 +85,7 @@ static struct option original_opts[] = {
        {.name = "numeric",       .has_arg = 0, .val = 'n'},
        {.name = "out-interface", .has_arg = 1, .val = 'o'},
        {.name = "verbose",       .has_arg = 0, .val = 'v'},
+       {.name = "wait",          .has_arg = 2, .val = 'w'},
        {.name = "exact",         .has_arg = 0, .val = 'x'},
        {.name = "fragments",     .has_arg = 0, .val = 'f'},
        {.name = "version",       .has_arg = 0, .val = 'V'},
@@ -683,6 +684,7 @@ int do_commandx(struct nft_handle *h, int argc, char *argv[], char **table,
 {
        struct iptables_command_state cs;
        int verbose = 0;
+       int wait = 0;
        const char *chain = NULL;
        const char *policy = NULL, *newname = NULL;
        unsigned int rulenum = 0, command = 0;
@@ -722,7 +724,7 @@ int do_commandx(struct nft_handle *h, int argc, char *argv[], char **table,
 
        opts = xt_params->orig_opts;
        while ((cs.c = getopt_long(argc, argv,
-          "-:A:C:D:R:I:L::S::M:F::Z::N:X::E:P:Vh::o:p:s:d:j:i:fbvnt:m:xc:g:46",
+          "-:A:C:D:R:I:L::S::M:F::Z::N:X::E:P:Vh::o:p:s:d:j:i:fbvw::nt:m:xc:g:46",
                                           opts, NULL)) != -1) {
                switch (cs.c) {
                        /*
@@ -1007,6 +1009,15 @@ int do_commandx(struct nft_handle *h, int argc, char *argv[], char **table,
                                              "You cannot use `-w' from "
                                              "iptables-restore");
                        }
+                       if (optarg) {
+                               if (sscanf(optarg, "%i", &wait) != 1)
+                                       xtables_error(PARAMETER_PROBLEM,
+                                                     "wait seconds not numeric");
+                       } else if (optind < argc && argv[optind][0] != '-'
+                                  && argv[optind][0] != '!')
+                               if (sscanf(argv[optind++], "%i", &wait) != 1)
+                                       xtables_error(PARAMETER_PROBLEM,
+                                                     "wait seconds not numeric");
                        break;
 
                case '0':