]> git.ipfire.org Git - thirdparty/iw.git/blobdiff - iw.c
iw: scan: parse 'supported Operating Classes element'
[thirdparty/iw.git] / iw.c
diff --git a/iw.c b/iw.c
index 98c0852153c02635cf9b85cf65bc7cbb0c76e881..da71617921d8a3c0a8e7c8c05f4e76dcba4987c0 100644 (file)
--- a/iw.c
+++ b/iw.c
@@ -13,6 +13,7 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <stdbool.h>
+#include <linux/netlink.h>
 
 #include <netlink/genl/genl.h>
 #include <netlink/genl/family.h>
@@ -34,6 +35,12 @@ static inline void nl_socket_free(struct nl_sock *h)
 {
        nl_handle_destroy(h);
 }
+
+static inline int nl_socket_set_buffer_size(struct nl_sock *sk,
+                                           int rxbuf, int txbuf)
+{
+       return nl_set_buffer_size(sk, rxbuf, txbuf);
+}
 #endif /* CONFIG_LIBNL20 && CONFIG_LIBNL30 */
 
 int iw_debug = 0;
@@ -54,6 +61,13 @@ static int nl80211_init(struct nl80211_state *state)
                goto out_handle_destroy;
        }
 
+       nl_socket_set_buffer_size(state->nl_sock, 8192, 8192);
+
+       /* try to set NETLINK_EXT_ACK to 1, ignoring errors */
+       err = 1;
+       setsockopt(nl_socket_get_fd(state->nl_sock), SOL_NETLINK,
+                  NETLINK_EXT_ACK, &err, sizeof(err));
+
        state->nl80211_id = genl_ctrl_resolve(state->nl_sock, "nl80211");
        if (state->nl80211_id < 0) {
                fprintf(stderr, "nl80211 not found.\n");
@@ -75,12 +89,12 @@ static void nl80211_cleanup(struct nl80211_state *state)
 
 static int cmd_size;
 
-extern struct cmd __start___cmd;
-extern struct cmd __stop___cmd;
+extern struct cmd *__start___cmd[];
+extern struct cmd *__stop___cmd;
 
-#define for_each_cmd(_cmd)                                     \
-       for (_cmd = &__start___cmd; _cmd < &__stop___cmd;               \
-            _cmd = (const struct cmd *)((char *)_cmd + cmd_size))
+#define for_each_cmd(_cmd, i)                                  \
+       for (i = 0; i < &__stop___cmd - __start___cmd; i++)     \
+               if ((_cmd = __start___cmd[i]))
 
 
 static void __usage_cmd(const struct cmd *cmd, char *indent, bool full)
@@ -105,9 +119,40 @@ static void __usage_cmd(const struct cmd *cmd, char *indent, bool full)
        if (cmd->parent && cmd->parent->name)
                printf("%s ", cmd->parent->name);
        printf("%s", cmd->name);
-       if (cmd->args)
-               printf(" %s", cmd->args);
-       printf("\n");
+
+       if (cmd->args) {
+               /* print line by line */
+               start = cmd->args;
+               end = strchr(start, '\0');
+               printf(" ");
+               do {
+                       lend = strchr(start, '\n');
+                       if (!lend)
+                               lend = end;
+                       if (start != cmd->args) {
+                               printf("\t");
+                               switch (cmd->idby) {
+                               case CIB_NONE:
+                                       break;
+                               case CIB_PHY:
+                                       printf("phy <phyname> ");
+                                       break;
+                               case CIB_NETDEV:
+                                       printf("dev <devname> ");
+                                       break;
+                               case CIB_WDEV:
+                                       printf("wdev <idx> ");
+                                       break;
+                               }
+                               if (cmd->parent && cmd->parent->name)
+                                       printf("%s ", cmd->parent->name);
+                               printf("%s ", cmd->name);
+                       }
+                       printf("%.*s\n", (int)(lend - start), start);
+                       start = lend + 1;
+               } while (end != lend);
+       } else
+               printf("\n");
 
        if (!full || !cmd->help)
                return;
@@ -147,6 +192,7 @@ static void usage(int argc, char **argv)
        bool full = argc >= 0;
        const char *sect_filt = NULL;
        const char *cmd_filt = NULL;
+       unsigned int i, j;
 
        if (argc > 0)
                sect_filt = argv[0];
@@ -158,7 +204,7 @@ static void usage(int argc, char **argv)
        usage_options();
        printf("\t--version\tshow version (%s)\n", iw_version);
        printf("Commands:\n");
-       for_each_cmd(section) {
+       for_each_cmd(section, i) {
                if (section->parent)
                        continue;
 
@@ -168,7 +214,7 @@ static void usage(int argc, char **argv)
                if (section->handler && !section->hidden)
                        __usage_cmd(section, "\t", full);
 
-               for_each_cmd(cmd) {
+               for_each_cmd(cmd, j) {
                        if (section != cmd->parent)
                                continue;
                        if (!cmd->handler || cmd->hidden)
@@ -178,6 +224,8 @@ static void usage(int argc, char **argv)
                        __usage_cmd(cmd, "\t", full);
                }
        }
+       printf("\nCommands that use the netdev ('dev') can also be given the\n"
+              "'wdev' instead to identify the device.\n");
        printf("\nYou can omit the 'phy' or 'dev' if "
                        "the identification is unique,\n"
                        "e.g. \"iw wlan0 info\" or \"iw phy0 info\". "
@@ -187,7 +235,6 @@ static void usage(int argc, char **argv)
 }
 
 static int print_help(struct nl80211_state *state,
-                     struct nl_cb *cb,
                      struct nl_msg *msg,
                      int argc, char **argv,
                      enum id_input id)
@@ -233,8 +280,35 @@ static int phy_lookup(char *name)
 static int error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err,
                         void *arg)
 {
+       struct nlmsghdr *nlh = (struct nlmsghdr *)err - 1;
+       int len = nlh->nlmsg_len;
+       struct nlattr *attrs;
+       struct nlattr *tb[NLMSGERR_ATTR_MAX + 1];
        int *ret = arg;
+       int ack_len = sizeof(*nlh) + sizeof(int) + sizeof(*nlh);
+
        *ret = err->error;
+
+       if (!(nlh->nlmsg_flags & NLM_F_ACK_TLVS))
+               return NL_STOP;
+
+       if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
+               ack_len += err->msg.nlmsg_len - sizeof(*nlh);
+
+       if (len <= ack_len)
+               return NL_STOP;
+
+       attrs = (void *)((unsigned char *)nlh + ack_len);
+       len -= ack_len;
+
+       nla_parse(tb, NLMSGERR_ATTR_MAX, attrs, len, NULL);
+       if (tb[NLMSGERR_ATTR_MSG]) {
+               len = strnlen((char *)nla_data(tb[NLMSGERR_ATTR_MSG]),
+                             nla_len(tb[NLMSGERR_ATTR_MSG]));
+               fprintf(stderr, "kernel reports: %*s\n", len,
+                       (char *)nla_data(tb[NLMSGERR_ATTR_MSG]));
+       }
+
        return NL_STOP;
 }
 
@@ -252,6 +326,23 @@ static int ack_handler(struct nl_msg *msg, void *arg)
        return NL_STOP;
 }
 
+static int (*registered_handler)(struct nl_msg *, void *);
+static void *registered_handler_data;
+
+void register_handler(int (*handler)(struct nl_msg *, void *), void *data)
+{
+       registered_handler = handler;
+       registered_handler_data = data;
+}
+
+int valid_handler(struct nl_msg *msg, void *arg)
+{
+       if (registered_handler)
+               return registered_handler(msg, registered_handler_data);
+
+       return NL_OK;
+}
+
 static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
                        int argc, char **argv, const struct cmd **cmdout)
 {
@@ -260,7 +351,7 @@ static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
        struct nl_cb *s_cb;
        struct nl_msg *msg;
        signed long long devidx = 0;
-       int err, o_argc;
+       int err, o_argc, i;
        const char *command, *section;
        char *tmp, **o_argv;
        enum command_identify_by command_idby = CIB_NONE;
@@ -312,7 +403,7 @@ static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
        argc--;
        argv++;
 
-       for_each_cmd(sectcmd) {
+       for_each_cmd(sectcmd, i) {
                if (sectcmd->parent)
                        continue;
                /* ok ... bit of a hack for the dupe 'info' section */
@@ -330,12 +421,18 @@ static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
        if (argc > 0) {
                command = *argv;
 
-               for_each_cmd(cmd) {
+               for_each_cmd(cmd, i) {
                        if (!cmd->handler)
                                continue;
                        if (cmd->parent != sectcmd)
                                continue;
-                       if (cmd->idby != command_idby)
+                       /*
+                        * ignore mismatch id by, but allow WDEV
+                        * in place of NETDEV
+                        */
+                       if (cmd->idby != command_idby &&
+                           !(cmd->idby == CIB_NETDEV &&
+                             command_idby == CIB_WDEV))
                                continue;
                        if (strcmp(cmd->name, command))
                                continue;
@@ -358,7 +455,8 @@ static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
                cmd = sectcmd;
                if (argc && !cmd->args)
                        return 1;
-               if (cmd->idby != command_idby)
+               if (cmd->idby != command_idby &&
+                   !(cmd->idby == CIB_NETDEV && command_idby == CIB_WDEV))
                        return 1;
                if (!cmd->handler)
                        return 1;
@@ -376,7 +474,7 @@ static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
        if (!cmd->cmd) {
                argc = o_argc;
                argv = o_argv;
-               return cmd->handler(state, NULL, NULL, argc, argv, idby);
+               return cmd->handler(state, NULL, argc, argv, idby);
        }
 
        msg = nlmsg_alloc();
@@ -390,7 +488,7 @@ static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
        if (!cb || !s_cb) {
                fprintf(stderr, "failed to allocate netlink callbacks\n");
                err = 2;
-               goto out_free_msg;
+               goto out;
        }
 
        genlmsg_put(msg, 0, 0, state->nl80211_id, 0,
@@ -410,7 +508,7 @@ static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
                break;
        }
 
-       err = cmd->handler(state, cb, msg, argc, argv, idby);
+       err = cmd->handler(state, msg, argc, argv, idby);
        if (err)
                goto out;
 
@@ -425,12 +523,13 @@ static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
        nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
        nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, &err);
        nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &err);
+       nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, valid_handler, NULL);
 
        while (err > 0)
                nl_recvmsgs(state->nl_sock, cb);
  out:
        nl_cb_put(cb);
- out_free_msg:
+       nl_cb_put(s_cb);
        nlmsg_free(msg);
        return err;
  nla_put_failure:
@@ -444,6 +543,25 @@ int handle_cmd(struct nl80211_state *state, enum id_input idby,
        return __handle_cmd(state, idby, argc, argv, NULL);
 }
 
+/*
+ * Unfortunately, I don't know how densely the linker packs the struct cmd.
+ * For example, if you have a 72-byte struct cmd, the linker will pad each
+ * out to 96 bytes before putting them together in the section. There must
+ * be some algorithm, but I haven't found it yet.
+ *
+ * We used to calculate this by taking the (abs value of) the difference
+ * between __section_get and __section_set, but if LTO is enabled then this
+ * stops working because the entries of the "__cmd" section get rearranged
+ * freely by the compiler/linker.
+ *
+ * Fix this by using yet another "__sizer" section that only contains these
+ * two entries - then the (abs value of) the difference between them will
+ * be how they get packed and that can be used to iterate the __cmd section
+ * as well.
+ */
+static struct cmd sizer1 __attribute__((section("__sizer"))) = {};
+static struct cmd sizer2 __attribute__((section("__sizer"))) = {};
+
 int main(int argc, char **argv)
 {
        struct nl80211_state nlstate;
@@ -451,7 +569,7 @@ int main(int argc, char **argv)
        const struct cmd *cmd = NULL;
 
        /* calculate command size including padding */
-       cmd_size = abs((long)&__section_set - (long)&__section_get);
+       cmd_size = labs((long)&sizer2 - (long)&sizer1);
        /* strip off self */
        argc--;
        argv0 = *argv++;
@@ -496,8 +614,9 @@ int main(int argc, char **argv)
                err = __handle_cmd(&nlstate, II_WDEV, argc, argv, &cmd);
        } else {
                int idx;
-               enum id_input idby = II_NONE;
+               enum id_input idby;
  detect:
+               idby = II_NONE;
                if ((idx = if_nametoindex(argv[0])) != 0)
                        idby = II_NETDEV;
                else if ((idx = phy_lookup(argv[0])) >= 0)
@@ -505,11 +624,13 @@ int main(int argc, char **argv)
                err = __handle_cmd(&nlstate, idby, argc, argv, &cmd);
        }
 
-       if (err == 1) {
+       if (err == HANDLER_RET_USAGE) {
                if (cmd)
                        usage_cmd(cmd);
                else
                        usage(0, NULL);
+       } else if (err == HANDLER_RET_DONE) {
+               err = 0;
        } else if (err < 0)
                fprintf(stderr, "command failed: %s (%d)\n", strerror(-err), err);