Use sideband also for challenge response.
[paraslash.git] / client_common.c
index eb9f9e1fcda2a49ba960582ba67be9c882897a20..eea14fa8d3a461ce9862b38af3c35a8e807e3568 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1997-2011 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 1997-2012 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -17,6 +17,7 @@
 #include "crypt.h"
 #include "net.h"
 #include "fd.h"
+#include "sideband.h"
 #include "string.h"
 #include "client.cmdline.h"
 #include "client.h"
 #define CLIENT_BUFSIZE 4000
 
 /**
- * Close the connection to para_server and free all resources.
+ * Close the connection to para_server and deallocate per-command ressources.
  *
- * \param ct Pointer to the client data.
+ * \param ct The client task.
  *
- * \sa client_open.
+ * This frees all ressources of the current command but keeps the configuration
+ * in \p ct->conf.
+ *
+ * \sa \ref client_close().
  */
-void client_close(struct client_task *ct)
+void client_disconnect(struct client_task *ct)
 {
        if (!ct)
                return;
        if (ct->scc.fd >= 0)
                close(ct->scc.fd);
+       free_argv(ct->features);
        sc_free(ct->scc.recv);
+       ct->scc.recv = NULL;
        sc_free(ct->scc.send);
+       ct->scc.send = NULL;
+       btr_free_node(ct->btrn);
+       ct->btrn = NULL;
+}
+
+/**
+ * Close the connection to para_server and free all resources.
+ *
+ * \param ct Pointer to the client data.
+ *
+ * \sa \ref client_open(), \ref client_disconnect().
+ */
+void client_close(struct client_task *ct)
+{
+       if (!ct)
+               return;
+       client_disconnect(ct);
        free(ct->user);
        free(ct->config_file);
        free(ct->key_file);
-       btr_free_node(ct->btrn);
        client_cmdline_parser_free(&ct->conf);
+       free(ct->challenge_hash);
+       sb_free(ct->sbc);
        free(ct);
 }
 
@@ -81,6 +105,7 @@ static void client_pre_select(struct sched *s, struct task *t)
 
        case CL_RECEIVED_WELCOME:
        case CL_RECEIVED_PROCEED:
+       case CL_RECEIVED_CHALLENGE:
                para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
                return;
 
@@ -132,6 +157,94 @@ static int client_recv_buffer(struct client_task *ct, fd_set *rfds,
        return 0;
 }
 
+static int send_sb(struct client_task *ct, void *buf, size_t numbytes,
+               enum sb_designator band, bool dont_free)
+{
+       int ret, fd = ct->scc.fd;
+       struct iovec iov[2];
+
+       if (!ct->sbc) {
+               struct sb_buffer sbb;
+               sb_transformation trafo = ct->status < CL_RECEIVED_PROCEED?
+                       NULL : sc_trafo;
+               sbb = (typeof(sbb))SBB_INIT(band, buf, numbytes);
+               ct->sbc = sb_new_send(&sbb, dont_free, trafo, ct->scc.send);
+       }
+       ret = sb_get_send_buffers(ct->sbc, iov);
+       ret = xwritev(fd, iov, ret);
+       if (ret < 0) {
+               sb_free(ct->sbc);
+               ct->sbc = NULL;
+               return ret;
+       }
+       if (sb_sent(ct->sbc, ret)) {
+               ct->sbc = NULL;
+               return 1;
+       }
+       return 0;
+}
+
+static int recv_sb(struct client_task *ct, fd_set *rfds,
+               struct sb_buffer *result)
+{
+       int ret;
+       size_t n;
+       sb_transformation trafo;
+       void *trafo_context;
+       struct iovec iov;
+
+       if (!FD_ISSET(ct->scc.fd, rfds))
+               return 0;
+       if (ct->status < CL_SENT_CH_RESPONSE)
+               trafo = trafo_context = NULL;
+       else {
+               trafo = sc_trafo;
+               trafo_context = ct->scc.recv;
+       }
+       if (!ct->sbc)
+               ct->sbc = sb_new_recv(0, trafo, trafo_context);
+again:
+       sb_get_recv_buffer(ct->sbc, &iov);
+       ret = read_nonblock(ct->scc.fd, iov.iov_base, iov.iov_len, rfds, &n);
+       if (ret < 0) {
+               sb_free(ct->sbc);
+               ct->sbc = NULL;
+               return ret;
+       }
+       if (n == 0)
+               return 0;
+       if (!sb_received(ct->sbc, n, result))
+               goto again;
+       ct->sbc = NULL;
+       return 1;
+}
+
+
+static char **parse_features(char *buf)
+{
+       int i;
+       const char id[] = "\nFeatures: ";
+       char *p, *q, **features;
+
+       p = strstr(buf, id);
+       if (!p)
+               return NULL;
+       p += strlen(id);
+       q = strchr(p, '\n');
+       if (!q)
+               return NULL;
+       *q = '\0';
+       create_argv(p, ",", &features);
+       for (i = 0; features[i]; i++)
+               PARA_INFO_LOG("server feature: %s\n", features[i]);
+       return features;
+}
+
+static bool has_feature(const char *feature, struct client_task *ct)
+{
+       return find_arg(feature, ct->features) >= 0? true : false;
+}
+
 /**
  * The post select hook for client commands.
  *
@@ -161,14 +274,19 @@ static void client_post_select(struct sched *s, struct task *t)
                ret = client_recv_buffer(ct, &s->rfds, buf, sizeof(buf), &n);
                if (ret < 0 || n == 0)
                        goto out;
+               ct->features = parse_features(buf);
                ct->status = CL_RECEIVED_WELCOME;
                return;
        case CL_RECEIVED_WELCOME: /* send auth command */
-               sprintf(buf, AUTH_REQUEST_MSG "%s", ct->user);
-               PARA_INFO_LOG("--> %s\n", buf);
                if (!FD_ISSET(ct->scc.fd, &s->wfds))
                        return;
-               ret = send_buffer(ct->scc.fd, buf);
+               if (has_feature("sideband", ct)) {
+                       ct->use_sideband = true;
+                       sprintf(buf, AUTH_REQUEST_MSG "%s sideband", ct->user);
+               } else
+                       sprintf(buf, AUTH_REQUEST_MSG "%s", ct->user);
+               PARA_INFO_LOG("--> %s\n", buf);
+               ret = write_buffer(ct->scc.fd, buf);
                if (ret < 0)
                        goto out;
                ct->status = CL_SENT_AUTH;
@@ -182,29 +300,59 @@ static void client_post_select(struct sched *s, struct task *t)
                /* decrypted challenge/session key buffer */
                unsigned char crypt_buf[1024];
                /* the SHA1 of the decrypted challenge */
-               unsigned char challenge_hash[HASH_SIZE];
 
-               ret = client_recv_buffer(ct, &s->rfds, buf, sizeof(buf), &n);
-               if (ret < 0 || n == 0)
-                       goto out;
-               PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
-               ret = priv_decrypt(ct->key_file, crypt_buf,
-                       (unsigned char *)buf, n);
-               if (ret < 0)
-                       goto out;
-               hash_function((char *)crypt_buf, CHALLENGE_SIZE, challenge_hash);
+               if (ct->use_sideband) {
+                       struct sb_buffer sbb;
+                       ret = recv_sb(ct, &s->rfds, &sbb);
+                       if (ret <= 0)
+                               goto out;
+                       if (sbb.band != SBD_CHALLENGE) {
+                               ret = -E_BAD_BAND;
+                               free(sbb.iov.iov_base);
+                                       goto out;
+                       }
+                       n = sbb.iov.iov_len;
+                       PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
+                       ret = priv_decrypt(ct->key_file, crypt_buf,
+                               sbb.iov.iov_base, n);
+                       free(sbb.iov.iov_base);
+                       if (ret < 0)
+                               goto out;
+               } else {
+                       ret = client_recv_buffer(ct, &s->rfds, buf, sizeof(buf), &n);
+                       if (ret < 0 || n == 0)
+                               goto out;
+                       PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
+                       ret = priv_decrypt(ct->key_file, crypt_buf,
+                               (unsigned char *)buf, n);
+                       if (ret < 0)
+                               goto out;
+               }
+               ct->challenge_hash = para_malloc(HASH_SIZE);
+               hash_function((char *)crypt_buf, CHALLENGE_SIZE, ct->challenge_hash);
                ct->scc.send = sc_new(crypt_buf + CHALLENGE_SIZE, SESSION_KEY_LEN);
                ct->scc.recv = sc_new(crypt_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
                        SESSION_KEY_LEN);
-               hash_to_asc(challenge_hash, buf);
+               hash_to_asc(ct->challenge_hash, buf);
                PARA_INFO_LOG("--> %s\n", buf);
-               ret = send_bin_buffer(ct->scc.fd, (char *)challenge_hash,
-                       HASH_SIZE);
-               if (ret < 0)
-                       goto out;
-               ct->status = CL_SENT_CH_RESPONSE;
+               ct->status = CL_RECEIVED_CHALLENGE;
                return;
                }
+       case CL_RECEIVED_CHALLENGE:
+               if (ct->use_sideband) {
+                       ret = send_sb(ct, ct->challenge_hash, HASH_SIZE,
+                               SBD_CHALLENGE_RESPONSE, false);
+                       if (ret != 0)
+                               ct->challenge_hash = NULL;
+                       if (ret <= 0)
+                               goto out;
+               } else {
+                       ret = write_all(ct->scc.fd, (char *)ct->challenge_hash, HASH_SIZE);
+                       if (ret < 0)
+                               goto out;
+               }
+               ct->status = CL_SENT_CH_RESPONSE;
+               goto out;
        case CL_SENT_CH_RESPONSE: /* read server response */
                {
                ret = client_recv_buffer(ct, &s->rfds, buf, sizeof(buf), &n);
@@ -303,31 +451,49 @@ static void client_post_select(struct sched *s, struct task *t)
 out:
        t->error = ret;
        if (ret < 0) {
-               if (ret != -E_SERVER_EOF && ret != -E_BTR_EOF)
+               if (ret != -E_SERVER_EOF && ret != -E_BTR_EOF && ret != -E_EOF)
                        PARA_ERROR_LOG("%s\n", para_strerror(-t->error));
                btr_remove_node(btrn);
        }
 }
 
-/* connect to para_server and register the client task */
-static int client_connect(struct client_task *ct)
+/**
+ * Connect to para_server and register the client task.
+ *
+ * \param ct The initialized client task structure.
+ * \param s The scheduler instance to register the client task to.
+ * \param parent The parent node of the client btr node.
+ * \param child The child node of the client node.
+ *
+ * The client task structure given by \a ct  must be allocated and initialized
+ * by \ref client_parse_config() before this function is called.
+ *
+ * \return Standard.
+ */
+int client_connect(struct client_task *ct, struct sched *s,
+               struct btr_node *parent, struct btr_node *child)
 {
        int ret;
 
+       PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
+               ct->conf.server_port_arg);
        ct->scc.fd = -1;
        ret = para_connect_simple(IPPROTO_TCP, ct->conf.hostname_arg,
                                               ct->conf.server_port_arg);
        if (ret < 0)
                return ret;
        ct->scc.fd = ret;
-       ct->status = CL_CONNECTED;
        ret = mark_fd_nonblocking(ct->scc.fd);
        if (ret < 0)
                goto err_out;
+       ct->status = CL_CONNECTED;
+       ct->btrn = btr_new_node(&(struct btr_node_description)
+               EMBRACE(.name = "client", .parent = parent, .child = child));
        ct->task.pre_select = client_pre_select;
        ct->task.post_select = client_post_select;
+       ct->task.error = 0;
        sprintf(ct->task.status, "client");
-       register_task(&ct->task);
+       register_task(s, &ct->task);
        return 1;
 err_out:
        close(ct->scc.fd);
@@ -336,40 +502,36 @@ err_out:
 }
 
 /**
- * Open connection to para_server.
+ * Parse a client configuration.
  *
  * \param argc Usual argument count.
  * \param argv Usual argument vector.
- * \param ct_ptr Points to dynamically allocated and initialized client task
- * struct upon successful return.
+ * \param ct_ptr Filled in by this function.
  * \param loglevel If not \p NULL, the number of the loglevel is stored here.
- * \param parent Add the new buffer tree node as a child of this node.
- * \param child Add the new buffer tree node as a parent of this node.
  *
- * Check the command line options given by \a argc and argv, set default values
- * for user name and rsa key file, read further option from the config file.
- * Finally, establish a connection to para_server.
+ * This checks the command line options given by \a argc and \a argv, sets
+ * default values for the user name and the name of the rsa key file and reads
+ * further options from the config file.
  *
- * \return Standard.
+ * Upon successful return, \a ct_ptr points to a dynamically allocated and
+ * initialized client task struct.
+ *
+ * \return The number of non-option arguments in \a argc/argv on success,
+ * negative on errors.
  */
-int client_open(int argc, char *argv[], struct client_task **ct_ptr,
-               int *loglevel, struct btr_node *parent, struct btr_node *child)
+int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
+               int *loglevel)
 {
        char *home = para_homedir();
        int ret;
        struct client_task *ct = para_calloc(sizeof(struct client_task));
 
-       ct->btrn = btr_new_node(&(struct btr_node_description)
-               EMBRACE(.name = "client", .parent = parent, .child = child));
        *ct_ptr = ct;
        ct->scc.fd = -1;
        ret = -E_CLIENT_SYNTAX;
        if (client_cmdline_parser(argc, argv, &ct->conf))
                goto out;
        HANDLE_VERSION_FLAG("client", ct->conf);
-       ret = -E_CLIENT_SYNTAX;
-       if (!ct->conf.inputs_num)
-               goto out;
 
        ct->config_file = ct->conf.config_file_given?
                para_strdup(ct->conf.config_file_arg) :
@@ -411,16 +573,52 @@ int client_open(int argc, char *argv[], struct client_task **ct_ptr,
        PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
        PARA_INFO_LOG("config_file: %s\n", ct->config_file);
        PARA_INFO_LOG("key_file: %s\n", ct->key_file);
-       PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
-               ct->conf.server_port_arg);
-       ret = client_connect(ct);
+       ret = ct->conf.inputs_num;
 out:
        free(home);
        if (ret < 0) {
                PARA_ERROR_LOG("%s\n", para_strerror(-ret));
-               btr_remove_node(ct->btrn);
                client_close(ct);
                *ct_ptr = NULL;
        }
        return ret;
 }
+
+/**
+ * Parse the client configuration and open a connection to para_server.
+ *
+ * \param argc See \ref client_parse_config.
+ * \param argv See \ref client_parse_config.
+ * \param ct_ptr See \ref client_parse_config.
+ * \param loglevel See \ref client_parse_config.
+ * \param parent See \ref client_connect().
+ * \param child See \ref client_connect().
+ * \param sched See \ref client_connect().
+ *
+ * This function combines client_parse_config() and client_connect(). It is
+ * considered a syntax error if no command was given, i.e. if the number
+ * of non-option arguments is zero.
+ *
+ * \return Standard.
+ */
+int client_open(int argc, char *argv[], struct client_task **ct_ptr,
+               int *loglevel, struct btr_node *parent, struct btr_node *child,
+               struct sched *sched)
+{
+       int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
+
+       if (ret < 0)
+               return ret;
+       if (ret == 0) {
+               ret = -E_CLIENT_SYNTAX;
+               goto fail;
+       }
+       ret = client_connect(*ct_ptr, sched, parent, child);
+       if (ret < 0)
+               goto fail;
+       return 1;
+fail:
+       client_close(*ct_ptr);
+       *ct_ptr = NULL;
+       return ret;
+}