1 | /* |
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2 | Xen Store Daemon interface providing simple tree-like database. |
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3 | Copyright (C) 2005 Rusty Russell IBM Corporation |
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4 | |
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5 | This library is free software; you can redistribute it and/or |
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6 | modify it under the terms of the GNU Lesser General Public |
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7 | License as published by the Free Software Foundation; either |
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8 | version 2.1 of the License, or (at your option) any later version. |
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9 | |
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10 | This library is distributed in the hope that it will be useful, |
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11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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13 | Lesser General Public License for more details. |
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14 | |
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15 | You should have received a copy of the GNU Lesser General Public |
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16 | License along with this library; if not, write to the Free Software |
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17 | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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18 | */ |
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19 | |
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20 | #include <sys/types.h> |
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21 | #include <sys/stat.h> |
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22 | #include <fcntl.h> |
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23 | #include <sys/socket.h> |
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24 | #include <sys/un.h> |
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25 | #include <string.h> |
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26 | #include <unistd.h> |
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27 | #include <stdbool.h> |
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28 | #include <stdlib.h> |
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29 | #include <assert.h> |
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30 | #include <stdio.h> |
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31 | #include <signal.h> |
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32 | #include <stdint.h> |
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33 | #include <errno.h> |
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34 | #include <pthread.h> |
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35 | #include "xs.h" |
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36 | #include "list.h" |
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37 | #include "utils.h" |
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38 | |
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39 | struct xs_stored_msg { |
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40 | struct list_head list; |
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41 | struct xsd_sockmsg hdr; |
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42 | char *body; |
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43 | }; |
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44 | |
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45 | struct xs_handle { |
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46 | /* Communications channel to xenstore daemon. */ |
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47 | int fd; |
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48 | |
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49 | /* |
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50 | * A read thread which pulls messages off the comms channel and |
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51 | * signals waiters. |
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52 | */ |
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53 | pthread_t read_thr; |
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54 | int read_thr_exists; |
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55 | |
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56 | /* |
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57 | * A list of fired watch messages, protected by a mutex. Users can |
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58 | * wait on the conditional variable until a watch is pending. |
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59 | */ |
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60 | struct list_head watch_list; |
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61 | pthread_mutex_t watch_mutex; |
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62 | pthread_cond_t watch_condvar; |
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63 | |
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64 | /* Clients can select() on this pipe to wait for a watch to fire. */ |
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65 | int watch_pipe[2]; |
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66 | |
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67 | /* |
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68 | * A list of replies. Currently only one will ever be outstanding |
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69 | * because we serialise requests. The requester can wait on the |
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70 | * conditional variable for its response. |
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71 | */ |
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72 | struct list_head reply_list; |
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73 | pthread_mutex_t reply_mutex; |
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74 | pthread_cond_t reply_condvar; |
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75 | |
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76 | /* One request at a time. */ |
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77 | pthread_mutex_t request_mutex; |
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78 | }; |
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79 | |
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80 | static int read_message(struct xs_handle *h); |
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81 | static void *read_thread(void *arg); |
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82 | |
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83 | int xs_fileno(struct xs_handle *h) |
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84 | { |
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85 | char c = 0; |
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86 | |
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87 | pthread_mutex_lock(&h->watch_mutex); |
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88 | |
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89 | if ((h->watch_pipe[0] == -1) && (pipe(h->watch_pipe) != -1)) { |
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90 | /* Kick things off if the watch list is already non-empty. */ |
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91 | if (!list_empty(&h->watch_list)) |
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92 | while (write(h->watch_pipe[1], &c, 1) != 1) |
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93 | continue; |
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94 | } |
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95 | |
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96 | pthread_mutex_unlock(&h->watch_mutex); |
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97 | |
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98 | return h->watch_pipe[0]; |
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99 | } |
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100 | |
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101 | static int get_socket(const char *connect_to) |
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102 | { |
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103 | struct sockaddr_un addr; |
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104 | int sock, saved_errno, flags; |
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105 | |
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106 | sock = socket(PF_UNIX, SOCK_STREAM, 0); |
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107 | if (sock < 0) |
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108 | return -1; |
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109 | |
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110 | if ((flags = fcntl(sock, F_GETFD)) < 0) |
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111 | goto error; |
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112 | flags |= FD_CLOEXEC; |
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113 | if (fcntl(sock, F_SETFD, flags) < 0) |
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114 | goto error; |
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115 | |
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116 | addr.sun_family = AF_UNIX; |
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117 | strcpy(addr.sun_path, connect_to); |
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118 | |
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119 | if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) != 0) |
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120 | goto error; |
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121 | |
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122 | return sock; |
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123 | |
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124 | error: |
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125 | saved_errno = errno; |
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126 | close(sock); |
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127 | errno = saved_errno; |
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128 | return -1; |
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129 | } |
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130 | |
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131 | static int get_dev(const char *connect_to) |
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132 | { |
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133 | return open(connect_to, O_RDWR); |
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134 | } |
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135 | |
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136 | static struct xs_handle *get_handle(const char *connect_to) |
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137 | { |
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138 | struct stat buf; |
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139 | struct xs_handle *h = NULL; |
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140 | int fd = -1, saved_errno; |
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141 | |
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142 | if (stat(connect_to, &buf) != 0) |
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143 | return NULL; |
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144 | |
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145 | if (S_ISSOCK(buf.st_mode)) |
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146 | fd = get_socket(connect_to); |
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147 | else |
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148 | fd = get_dev(connect_to); |
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149 | |
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150 | if (fd == -1) |
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151 | return NULL; |
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152 | |
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153 | h = malloc(sizeof(*h)); |
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154 | if (h == NULL) { |
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155 | saved_errno = errno; |
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156 | close(fd); |
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157 | errno = saved_errno; |
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158 | return NULL; |
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159 | } |
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160 | |
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161 | memset(h, 0, sizeof(*h)); |
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162 | |
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163 | h->fd = fd; |
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164 | |
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165 | /* Watch pipe is allocated on demand in xs_fileno(). */ |
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166 | h->watch_pipe[0] = h->watch_pipe[1] = -1; |
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167 | |
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168 | INIT_LIST_HEAD(&h->watch_list); |
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169 | pthread_mutex_init(&h->watch_mutex, NULL); |
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170 | pthread_cond_init(&h->watch_condvar, NULL); |
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171 | |
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172 | INIT_LIST_HEAD(&h->reply_list); |
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173 | pthread_mutex_init(&h->reply_mutex, NULL); |
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174 | pthread_cond_init(&h->reply_condvar, NULL); |
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175 | |
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176 | pthread_mutex_init(&h->request_mutex, NULL); |
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177 | |
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178 | return h; |
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179 | } |
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180 | |
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181 | struct xs_handle *xs_daemon_open(void) |
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182 | { |
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183 | return get_handle(xs_daemon_socket()); |
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184 | } |
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185 | |
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186 | struct xs_handle *xs_daemon_open_readonly(void) |
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187 | { |
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188 | return get_handle(xs_daemon_socket_ro()); |
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189 | } |
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190 | |
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191 | struct xs_handle *xs_domain_open(void) |
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192 | { |
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193 | return get_handle(xs_domain_dev()); |
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194 | } |
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195 | |
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196 | void xs_daemon_close(struct xs_handle *h) |
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197 | { |
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198 | struct xs_stored_msg *msg, *tmsg; |
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199 | |
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200 | pthread_mutex_lock(&h->request_mutex); |
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201 | pthread_mutex_lock(&h->reply_mutex); |
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202 | pthread_mutex_lock(&h->watch_mutex); |
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203 | |
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204 | if (h->read_thr_exists) { |
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205 | /* XXX FIXME: May leak an unpublished message buffer. */ |
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206 | pthread_cancel(h->read_thr); |
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207 | pthread_join(h->read_thr, NULL); |
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208 | } |
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209 | |
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210 | list_for_each_entry_safe(msg, tmsg, &h->reply_list, list) { |
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211 | free(msg->body); |
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212 | free(msg); |
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213 | } |
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214 | |
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215 | list_for_each_entry_safe(msg, tmsg, &h->watch_list, list) { |
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216 | free(msg->body); |
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217 | free(msg); |
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218 | } |
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219 | |
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220 | pthread_mutex_unlock(&h->request_mutex); |
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221 | pthread_mutex_unlock(&h->reply_mutex); |
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222 | pthread_mutex_unlock(&h->watch_mutex); |
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223 | |
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224 | if (h->watch_pipe[0] != -1) { |
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225 | close(h->watch_pipe[0]); |
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226 | close(h->watch_pipe[1]); |
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227 | } |
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228 | |
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229 | close(h->fd); |
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230 | |
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231 | free(h); |
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232 | } |
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233 | |
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234 | static bool read_all(int fd, void *data, unsigned int len) |
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235 | { |
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236 | while (len) { |
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237 | int done; |
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238 | |
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239 | done = read(fd, data, len); |
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240 | if (done < 0) { |
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241 | if (errno == EINTR) |
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242 | continue; |
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243 | return false; |
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244 | } |
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245 | if (done == 0) { |
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246 | /* It closed fd on us? EBADF is appropriate. */ |
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247 | errno = EBADF; |
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248 | return false; |
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249 | } |
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250 | data += done; |
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251 | len -= done; |
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252 | } |
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253 | |
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254 | return true; |
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255 | } |
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256 | |
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257 | #ifdef XSTEST |
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258 | #define read_all read_all_choice |
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259 | #define xs_write_all write_all_choice |
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260 | #endif |
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261 | |
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262 | static int get_error(const char *errorstring) |
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263 | { |
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264 | unsigned int i; |
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265 | |
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266 | for (i = 0; !streq(errorstring, xsd_errors[i].errstring); i++) |
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267 | if (i == ARRAY_SIZE(xsd_errors) - 1) |
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268 | return EINVAL; |
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269 | return xsd_errors[i].errnum; |
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270 | } |
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271 | |
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272 | /* Adds extra nul terminator, because we generally (always?) hold strings. */ |
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273 | static void *read_reply( |
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274 | struct xs_handle *h, enum xsd_sockmsg_type *type, unsigned int *len) |
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275 | { |
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276 | struct xs_stored_msg *msg; |
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277 | char *body; |
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278 | |
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279 | /* Read from comms channel ourselves if there is no reader thread. */ |
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280 | if (!h->read_thr_exists && (read_message(h) == -1)) |
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281 | return NULL; |
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282 | |
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283 | pthread_mutex_lock(&h->reply_mutex); |
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284 | while (list_empty(&h->reply_list)) |
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285 | pthread_cond_wait(&h->reply_condvar, &h->reply_mutex); |
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286 | msg = list_top(&h->reply_list, struct xs_stored_msg, list); |
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287 | list_del(&msg->list); |
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288 | assert(list_empty(&h->reply_list)); |
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289 | pthread_mutex_unlock(&h->reply_mutex); |
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290 | |
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291 | *type = msg->hdr.type; |
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292 | if (len) |
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293 | *len = msg->hdr.len; |
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294 | body = msg->body; |
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295 | |
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296 | free(msg); |
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297 | |
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298 | return body; |
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299 | } |
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300 | |
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301 | /* Send message to xs, get malloc'ed reply. NULL and set errno on error. */ |
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302 | static void *xs_talkv(struct xs_handle *h, xs_transaction_t t, |
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303 | enum xsd_sockmsg_type type, |
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304 | const struct iovec *iovec, |
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305 | unsigned int num_vecs, |
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306 | unsigned int *len) |
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307 | { |
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308 | struct xsd_sockmsg msg; |
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309 | void *ret = NULL; |
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310 | int saved_errno; |
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311 | unsigned int i; |
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312 | struct sigaction ignorepipe, oldact; |
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313 | |
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314 | msg.tx_id = t; |
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315 | msg.req_id = 0; |
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316 | msg.type = type; |
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317 | msg.len = 0; |
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318 | for (i = 0; i < num_vecs; i++) |
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319 | msg.len += iovec[i].iov_len; |
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320 | |
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321 | ignorepipe.sa_handler = SIG_IGN; |
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322 | sigemptyset(&ignorepipe.sa_mask); |
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323 | ignorepipe.sa_flags = 0; |
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324 | sigaction(SIGPIPE, &ignorepipe, &oldact); |
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325 | |
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326 | pthread_mutex_lock(&h->request_mutex); |
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327 | |
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328 | if (!xs_write_all(h->fd, &msg, sizeof(msg))) |
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329 | goto fail; |
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330 | |
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331 | for (i = 0; i < num_vecs; i++) |
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332 | if (!xs_write_all(h->fd, iovec[i].iov_base, iovec[i].iov_len)) |
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333 | goto fail; |
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334 | |
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335 | ret = read_reply(h, &msg.type, len); |
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336 | if (!ret) |
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337 | goto fail; |
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338 | |
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339 | pthread_mutex_unlock(&h->request_mutex); |
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340 | |
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341 | sigaction(SIGPIPE, &oldact, NULL); |
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342 | if (msg.type == XS_ERROR) { |
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343 | saved_errno = get_error(ret); |
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344 | free(ret); |
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345 | errno = saved_errno; |
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346 | return NULL; |
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347 | } |
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348 | |
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349 | if (msg.type != type) { |
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350 | free(ret); |
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351 | saved_errno = EBADF; |
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352 | goto close_fd; |
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353 | } |
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354 | return ret; |
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355 | |
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356 | fail: |
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357 | /* We're in a bad state, so close fd. */ |
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358 | saved_errno = errno; |
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359 | pthread_mutex_unlock(&h->request_mutex); |
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360 | sigaction(SIGPIPE, &oldact, NULL); |
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361 | close_fd: |
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362 | close(h->fd); |
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363 | h->fd = -1; |
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364 | errno = saved_errno; |
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365 | return NULL; |
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366 | } |
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367 | |
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368 | /* free(), but don't change errno. */ |
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369 | static void free_no_errno(void *p) |
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370 | { |
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371 | int saved_errno = errno; |
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372 | free(p); |
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373 | errno = saved_errno; |
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374 | } |
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375 | |
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376 | /* Simplified version of xs_talkv: single message. */ |
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377 | static void *xs_single(struct xs_handle *h, xs_transaction_t t, |
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378 | enum xsd_sockmsg_type type, |
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379 | const char *string, |
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380 | unsigned int *len) |
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381 | { |
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382 | struct iovec iovec; |
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383 | |
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384 | iovec.iov_base = (void *)string; |
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385 | iovec.iov_len = strlen(string) + 1; |
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386 | return xs_talkv(h, t, type, &iovec, 1, len); |
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387 | } |
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388 | |
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389 | static bool xs_bool(char *reply) |
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390 | { |
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391 | if (!reply) |
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392 | return false; |
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393 | free(reply); |
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394 | return true; |
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395 | } |
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396 | |
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397 | char **xs_directory(struct xs_handle *h, xs_transaction_t t, |
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398 | const char *path, unsigned int *num) |
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399 | { |
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400 | char *strings, *p, **ret; |
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401 | unsigned int len; |
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402 | |
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403 | strings = xs_single(h, t, XS_DIRECTORY, path, &len); |
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404 | if (!strings) |
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405 | return NULL; |
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406 | |
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407 | /* Count the strings. */ |
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408 | *num = xs_count_strings(strings, len); |
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409 | |
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410 | /* Transfer to one big alloc for easy freeing. */ |
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411 | ret = malloc(*num * sizeof(char *) + len); |
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412 | if (!ret) { |
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413 | free_no_errno(strings); |
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414 | return NULL; |
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415 | } |
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416 | memcpy(&ret[*num], strings, len); |
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417 | free_no_errno(strings); |
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418 | |
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419 | strings = (char *)&ret[*num]; |
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420 | for (p = strings, *num = 0; p < strings + len; p += strlen(p) + 1) |
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421 | ret[(*num)++] = p; |
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422 | return ret; |
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423 | } |
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424 | |
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425 | /* Get the value of a single file, nul terminated. |
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426 | * Returns a malloced value: call free() on it after use. |
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427 | * len indicates length in bytes, not including the nul. |
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428 | */ |
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429 | void *xs_read(struct xs_handle *h, xs_transaction_t t, |
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430 | const char *path, unsigned int *len) |
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431 | { |
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432 | return xs_single(h, t, XS_READ, path, len); |
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433 | } |
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434 | |
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435 | /* Write the value of a single file. |
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436 | * Returns false on failure. |
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437 | */ |
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438 | bool xs_write(struct xs_handle *h, xs_transaction_t t, |
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439 | const char *path, const void *data, unsigned int len) |
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440 | { |
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441 | struct iovec iovec[2]; |
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442 | |
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443 | iovec[0].iov_base = (void *)path; |
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444 | iovec[0].iov_len = strlen(path) + 1; |
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445 | iovec[1].iov_base = (void *)data; |
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446 | iovec[1].iov_len = len; |
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447 | |
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448 | return xs_bool(xs_talkv(h, t, XS_WRITE, iovec, |
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449 | ARRAY_SIZE(iovec), NULL)); |
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450 | } |
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451 | |
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452 | /* Create a new directory. |
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453 | * Returns false on failure, or success if it already exists. |
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454 | */ |
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455 | bool xs_mkdir(struct xs_handle *h, xs_transaction_t t, |
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456 | const char *path) |
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457 | { |
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458 | return xs_bool(xs_single(h, t, XS_MKDIR, path, NULL)); |
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459 | } |
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460 | |
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461 | /* Destroy a file or directory (directories must be empty). |
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462 | * Returns false on failure, or success if it doesn't exist. |
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463 | */ |
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464 | bool xs_rm(struct xs_handle *h, xs_transaction_t t, |
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465 | const char *path) |
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466 | { |
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467 | return xs_bool(xs_single(h, t, XS_RM, path, NULL)); |
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468 | } |
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469 | |
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470 | /* Get permissions of node (first element is owner). |
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471 | * Returns malloced array, or NULL: call free() after use. |
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472 | */ |
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473 | struct xs_permissions *xs_get_permissions(struct xs_handle *h, |
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474 | xs_transaction_t t, |
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475 | const char *path, unsigned int *num) |
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476 | { |
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477 | char *strings; |
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478 | unsigned int len; |
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479 | struct xs_permissions *ret; |
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480 | |
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481 | strings = xs_single(h, t, XS_GET_PERMS, path, &len); |
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482 | if (!strings) |
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483 | return NULL; |
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484 | |
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485 | /* Count the strings: each one perms then domid. */ |
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486 | *num = xs_count_strings(strings, len); |
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487 | |
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488 | /* Transfer to one big alloc for easy freeing. */ |
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489 | ret = malloc(*num * sizeof(struct xs_permissions)); |
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490 | if (!ret) { |
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491 | free_no_errno(strings); |
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492 | return NULL; |
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493 | } |
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494 | |
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495 | if (!xs_strings_to_perms(ret, *num, strings)) { |
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496 | free_no_errno(ret); |
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497 | ret = NULL; |
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498 | } |
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499 | |
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500 | free(strings); |
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501 | return ret; |
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502 | } |
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503 | |
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504 | /* Set permissions of node (must be owner). |
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505 | * Returns false on failure. |
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506 | */ |
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507 | bool xs_set_permissions(struct xs_handle *h, |
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508 | xs_transaction_t t, |
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509 | const char *path, |
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510 | struct xs_permissions *perms, |
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511 | unsigned int num_perms) |
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512 | { |
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513 | unsigned int i; |
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514 | struct iovec iov[1+num_perms]; |
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515 | |
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516 | iov[0].iov_base = (void *)path; |
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517 | iov[0].iov_len = strlen(path) + 1; |
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518 | |
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519 | for (i = 0; i < num_perms; i++) { |
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520 | char buffer[MAX_STRLEN(unsigned int)+1]; |
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521 | |
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522 | if (!xs_perm_to_string(&perms[i], buffer)) |
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523 | goto unwind; |
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524 | |
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525 | iov[i+1].iov_base = strdup(buffer); |
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526 | iov[i+1].iov_len = strlen(buffer) + 1; |
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527 | if (!iov[i+1].iov_base) |
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528 | goto unwind; |
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529 | } |
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530 | |
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531 | if (!xs_bool(xs_talkv(h, t, XS_SET_PERMS, iov, 1+num_perms, NULL))) |
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532 | goto unwind; |
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533 | for (i = 0; i < num_perms; i++) |
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534 | free(iov[i+1].iov_base); |
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535 | return true; |
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536 | |
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537 | unwind: |
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538 | num_perms = i; |
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539 | for (i = 0; i < num_perms; i++) |
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540 | free_no_errno(iov[i+1].iov_base); |
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541 | return false; |
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542 | } |
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543 | |
---|
544 | /* Watch a node for changes (poll on fd to detect, or call read_watch()). |
---|
545 | * When the node (or any child) changes, fd will become readable. |
---|
546 | * Token is returned when watch is read, to allow matching. |
---|
547 | * Returns false on failure. |
---|
548 | */ |
---|
549 | bool xs_watch(struct xs_handle *h, const char *path, const char *token) |
---|
550 | { |
---|
551 | struct iovec iov[2]; |
---|
552 | |
---|
553 | /* We dynamically create a reader thread on demand. */ |
---|
554 | pthread_mutex_lock(&h->request_mutex); |
---|
555 | if (!h->read_thr_exists) { |
---|
556 | if (pthread_create(&h->read_thr, NULL, read_thread, h) != 0) { |
---|
557 | pthread_mutex_unlock(&h->request_mutex); |
---|
558 | return false; |
---|
559 | } |
---|
560 | h->read_thr_exists = 1; |
---|
561 | } |
---|
562 | pthread_mutex_unlock(&h->request_mutex); |
---|
563 | |
---|
564 | iov[0].iov_base = (void *)path; |
---|
565 | iov[0].iov_len = strlen(path) + 1; |
---|
566 | iov[1].iov_base = (void *)token; |
---|
567 | iov[1].iov_len = strlen(token) + 1; |
---|
568 | |
---|
569 | return xs_bool(xs_talkv(h, XBT_NULL, XS_WATCH, iov, |
---|
570 | ARRAY_SIZE(iov), NULL)); |
---|
571 | } |
---|
572 | |
---|
573 | /* Find out what node change was on (will block if nothing pending). |
---|
574 | * Returns array of two pointers: path and token, or NULL. |
---|
575 | * Call free() after use. |
---|
576 | */ |
---|
577 | char **xs_read_watch(struct xs_handle *h, unsigned int *num) |
---|
578 | { |
---|
579 | struct xs_stored_msg *msg; |
---|
580 | char **ret, *strings, c = 0; |
---|
581 | unsigned int num_strings, i; |
---|
582 | |
---|
583 | pthread_mutex_lock(&h->watch_mutex); |
---|
584 | |
---|
585 | /* Wait on the condition variable for a watch to fire. */ |
---|
586 | while (list_empty(&h->watch_list)) |
---|
587 | pthread_cond_wait(&h->watch_condvar, &h->watch_mutex); |
---|
588 | msg = list_top(&h->watch_list, struct xs_stored_msg, list); |
---|
589 | list_del(&msg->list); |
---|
590 | |
---|
591 | /* Clear the pipe token if there are no more pending watches. */ |
---|
592 | if (list_empty(&h->watch_list) && (h->watch_pipe[0] != -1)) |
---|
593 | while (read(h->watch_pipe[0], &c, 1) != 1) |
---|
594 | continue; |
---|
595 | |
---|
596 | pthread_mutex_unlock(&h->watch_mutex); |
---|
597 | |
---|
598 | assert(msg->hdr.type == XS_WATCH_EVENT); |
---|
599 | |
---|
600 | strings = msg->body; |
---|
601 | num_strings = xs_count_strings(strings, msg->hdr.len); |
---|
602 | |
---|
603 | ret = malloc(sizeof(char*) * num_strings + msg->hdr.len); |
---|
604 | if (!ret) { |
---|
605 | free_no_errno(strings); |
---|
606 | free_no_errno(msg); |
---|
607 | return NULL; |
---|
608 | } |
---|
609 | |
---|
610 | ret[0] = (char *)(ret + num_strings); |
---|
611 | memcpy(ret[0], strings, msg->hdr.len); |
---|
612 | |
---|
613 | free(strings); |
---|
614 | free(msg); |
---|
615 | |
---|
616 | for (i = 1; i < num_strings; i++) |
---|
617 | ret[i] = ret[i - 1] + strlen(ret[i - 1]) + 1; |
---|
618 | |
---|
619 | *num = num_strings; |
---|
620 | |
---|
621 | return ret; |
---|
622 | } |
---|
623 | |
---|
624 | /* Remove a watch on a node. |
---|
625 | * Returns false on failure (no watch on that node). |
---|
626 | */ |
---|
627 | bool xs_unwatch(struct xs_handle *h, const char *path, const char *token) |
---|
628 | { |
---|
629 | struct iovec iov[2]; |
---|
630 | |
---|
631 | iov[0].iov_base = (char *)path; |
---|
632 | iov[0].iov_len = strlen(path) + 1; |
---|
633 | iov[1].iov_base = (char *)token; |
---|
634 | iov[1].iov_len = strlen(token) + 1; |
---|
635 | |
---|
636 | return xs_bool(xs_talkv(h, XBT_NULL, XS_UNWATCH, iov, |
---|
637 | ARRAY_SIZE(iov), NULL)); |
---|
638 | } |
---|
639 | |
---|
640 | /* Start a transaction: changes by others will not be seen during this |
---|
641 | * transaction, and changes will not be visible to others until end. |
---|
642 | * You can only have one transaction at any time. |
---|
643 | * Returns XBT_NULL on failure. |
---|
644 | */ |
---|
645 | xs_transaction_t xs_transaction_start(struct xs_handle *h) |
---|
646 | { |
---|
647 | char *id_str; |
---|
648 | xs_transaction_t id; |
---|
649 | |
---|
650 | id_str = xs_single(h, XBT_NULL, XS_TRANSACTION_START, "", NULL); |
---|
651 | if (id_str == NULL) |
---|
652 | return XBT_NULL; |
---|
653 | |
---|
654 | id = strtoul(id_str, NULL, 0); |
---|
655 | free(id_str); |
---|
656 | |
---|
657 | return id; |
---|
658 | } |
---|
659 | |
---|
660 | /* End a transaction. |
---|
661 | * If abandon is true, transaction is discarded instead of committed. |
---|
662 | * Returns false on failure, which indicates an error: transactions will |
---|
663 | * not fail spuriously. |
---|
664 | */ |
---|
665 | bool xs_transaction_end(struct xs_handle *h, xs_transaction_t t, |
---|
666 | bool abort) |
---|
667 | { |
---|
668 | char abortstr[2]; |
---|
669 | |
---|
670 | if (abort) |
---|
671 | strcpy(abortstr, "F"); |
---|
672 | else |
---|
673 | strcpy(abortstr, "T"); |
---|
674 | |
---|
675 | return xs_bool(xs_single(h, t, XS_TRANSACTION_END, abortstr, NULL)); |
---|
676 | } |
---|
677 | |
---|
678 | /* Introduce a new domain. |
---|
679 | * This tells the store daemon about a shared memory page and event channel |
---|
680 | * associated with a domain: the domain uses these to communicate. |
---|
681 | */ |
---|
682 | bool xs_introduce_domain(struct xs_handle *h, |
---|
683 | unsigned int domid, unsigned long mfn, |
---|
684 | unsigned int eventchn) |
---|
685 | { |
---|
686 | char domid_str[MAX_STRLEN(domid)]; |
---|
687 | char mfn_str[MAX_STRLEN(mfn)]; |
---|
688 | char eventchn_str[MAX_STRLEN(eventchn)]; |
---|
689 | struct iovec iov[3]; |
---|
690 | |
---|
691 | sprintf(domid_str, "%u", domid); |
---|
692 | sprintf(mfn_str, "%lu", mfn); |
---|
693 | sprintf(eventchn_str, "%u", eventchn); |
---|
694 | |
---|
695 | iov[0].iov_base = domid_str; |
---|
696 | iov[0].iov_len = strlen(domid_str) + 1; |
---|
697 | iov[1].iov_base = mfn_str; |
---|
698 | iov[1].iov_len = strlen(mfn_str) + 1; |
---|
699 | iov[2].iov_base = eventchn_str; |
---|
700 | iov[2].iov_len = strlen(eventchn_str) + 1; |
---|
701 | |
---|
702 | return xs_bool(xs_talkv(h, XBT_NULL, XS_INTRODUCE, iov, |
---|
703 | ARRAY_SIZE(iov), NULL)); |
---|
704 | } |
---|
705 | |
---|
706 | static void * single_with_domid(struct xs_handle *h, |
---|
707 | enum xsd_sockmsg_type type, |
---|
708 | unsigned int domid) |
---|
709 | { |
---|
710 | char domid_str[MAX_STRLEN(domid)]; |
---|
711 | |
---|
712 | sprintf(domid_str, "%u", domid); |
---|
713 | |
---|
714 | return xs_single(h, XBT_NULL, type, domid_str, NULL); |
---|
715 | } |
---|
716 | |
---|
717 | bool xs_release_domain(struct xs_handle *h, unsigned int domid) |
---|
718 | { |
---|
719 | return xs_bool(single_with_domid(h, XS_RELEASE, domid)); |
---|
720 | } |
---|
721 | |
---|
722 | /* clear the shutdown bit for the given domain */ |
---|
723 | bool xs_resume_domain(struct xs_handle *h, unsigned int domid) |
---|
724 | { |
---|
725 | return xs_bool(single_with_domid(h, XS_RESUME, domid)); |
---|
726 | } |
---|
727 | |
---|
728 | char *xs_get_domain_path(struct xs_handle *h, unsigned int domid) |
---|
729 | { |
---|
730 | char domid_str[MAX_STRLEN(domid)]; |
---|
731 | |
---|
732 | sprintf(domid_str, "%u", domid); |
---|
733 | |
---|
734 | return xs_single(h, XBT_NULL, XS_GET_DOMAIN_PATH, domid_str, NULL); |
---|
735 | } |
---|
736 | |
---|
737 | bool xs_is_domain_introduced(struct xs_handle *h, unsigned int domid) |
---|
738 | { |
---|
739 | return strcmp("F", |
---|
740 | single_with_domid(h, XS_IS_DOMAIN_INTRODUCED, domid)); |
---|
741 | } |
---|
742 | |
---|
743 | /* Only useful for DEBUG versions */ |
---|
744 | char *xs_debug_command(struct xs_handle *h, const char *cmd, |
---|
745 | void *data, unsigned int len) |
---|
746 | { |
---|
747 | struct iovec iov[2]; |
---|
748 | |
---|
749 | iov[0].iov_base = (void *)cmd; |
---|
750 | iov[0].iov_len = strlen(cmd) + 1; |
---|
751 | iov[1].iov_base = data; |
---|
752 | iov[1].iov_len = len; |
---|
753 | |
---|
754 | return xs_talkv(h, XBT_NULL, XS_DEBUG, iov, |
---|
755 | ARRAY_SIZE(iov), NULL); |
---|
756 | } |
---|
757 | |
---|
758 | static int read_message(struct xs_handle *h) |
---|
759 | { |
---|
760 | struct xs_stored_msg *msg = NULL; |
---|
761 | char *body = NULL; |
---|
762 | int saved_errno; |
---|
763 | |
---|
764 | /* Allocate message structure and read the message header. */ |
---|
765 | msg = malloc(sizeof(*msg)); |
---|
766 | if (msg == NULL) |
---|
767 | goto error; |
---|
768 | if (!read_all(h->fd, &msg->hdr, sizeof(msg->hdr))) |
---|
769 | goto error; |
---|
770 | |
---|
771 | /* Allocate and read the message body. */ |
---|
772 | body = msg->body = malloc(msg->hdr.len + 1); |
---|
773 | if (body == NULL) |
---|
774 | goto error; |
---|
775 | if (!read_all(h->fd, body, msg->hdr.len)) |
---|
776 | goto error; |
---|
777 | body[msg->hdr.len] = '\0'; |
---|
778 | |
---|
779 | if (msg->hdr.type == XS_WATCH_EVENT) { |
---|
780 | pthread_mutex_lock(&h->watch_mutex); |
---|
781 | |
---|
782 | /* Kick users out of their select() loop. */ |
---|
783 | if (list_empty(&h->watch_list) && |
---|
784 | (h->watch_pipe[1] != -1)) |
---|
785 | while (write(h->watch_pipe[1], body, 1) != 1) |
---|
786 | continue; |
---|
787 | |
---|
788 | list_add_tail(&msg->list, &h->watch_list); |
---|
789 | pthread_cond_signal(&h->watch_condvar); |
---|
790 | |
---|
791 | pthread_mutex_unlock(&h->watch_mutex); |
---|
792 | } else { |
---|
793 | pthread_mutex_lock(&h->reply_mutex); |
---|
794 | |
---|
795 | /* There should only ever be one response pending! */ |
---|
796 | if (!list_empty(&h->reply_list)) { |
---|
797 | pthread_mutex_unlock(&h->reply_mutex); |
---|
798 | goto error; |
---|
799 | } |
---|
800 | |
---|
801 | list_add_tail(&msg->list, &h->reply_list); |
---|
802 | pthread_cond_signal(&h->reply_condvar); |
---|
803 | |
---|
804 | pthread_mutex_unlock(&h->reply_mutex); |
---|
805 | } |
---|
806 | |
---|
807 | return 0; |
---|
808 | |
---|
809 | error: |
---|
810 | saved_errno = errno; |
---|
811 | free(msg); |
---|
812 | free(body); |
---|
813 | errno = saved_errno; |
---|
814 | return -1; |
---|
815 | } |
---|
816 | |
---|
817 | static void *read_thread(void *arg) |
---|
818 | { |
---|
819 | struct xs_handle *h = arg; |
---|
820 | |
---|
821 | while (read_message(h) != -1) |
---|
822 | continue; |
---|
823 | |
---|
824 | return NULL; |
---|
825 | } |
---|
826 | |
---|
827 | /* |
---|
828 | * Local variables: |
---|
829 | * c-file-style: "linux" |
---|
830 | * indent-tabs-mode: t |
---|
831 | * c-indent-level: 8 |
---|
832 | * c-basic-offset: 8 |
---|
833 | * tab-width: 8 |
---|
834 | * End: |
---|
835 | */ |
---|