From 9e2e05f3495c883356be93232b26d6cbb796a269 Mon Sep 17 00:00:00 2001 From: lakshminarayanagurram Date: Mon, 25 Feb 2019 11:02:24 +0100 Subject: [PATCH] Add a groupchat example program that uses the submesh feature. --- examples/Makefile.am | 5 +- examples/groupchat.c | 469 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 473 insertions(+), 1 deletion(-) create mode 100644 examples/groupchat.c diff --git a/examples/Makefile.am b/examples/Makefile.am index 9243cafb..fbd71382 100644 --- a/examples/Makefile.am +++ b/examples/Makefile.am @@ -1,4 +1,4 @@ -noinst_PROGRAMS = meshlinkapp chat chatpp manynodes channels monitor +noinst_PROGRAMS = meshlinkapp chat chatpp manynodes channels monitor groupchat AM_CPPFLAGS = $(PTHREAD_CFLAGS) -I${top_srcdir}/src -iquote. -Wall AM_LDFLAGS = $(PTHREAD_LIBS) @@ -22,3 +22,6 @@ if CURSES monitor_SOURCES = monitor.c monitor_LDADD = ${top_builddir}/src/libmeshlink.la $(NCURSES_LIBS) -lm endif + +groupchat_SOURCES = groupchat.c +groupchat_LDADD = ${top_builddir}/src/libmeshlink.la diff --git a/examples/groupchat.c b/examples/groupchat.c new file mode 100644 index 00000000..a866943a --- /dev/null +++ b/examples/groupchat.c @@ -0,0 +1,469 @@ +#include +#include +#include +#include + +#include "../src/meshlink.h" +#include "../src/devtools.h" + +#define CHAT_PORT 531 + +static void log_message(meshlink_handle_t *mesh, meshlink_log_level_t level, const char *text) { + (void) mesh; + + static const char *levelstr[] = { + [MESHLINK_DEBUG] = "\x1b[34mDEBUG", + [MESHLINK_INFO] = "\x1b[32mINFO", + [MESHLINK_WARNING] = "\x1b[33mWARNING", + [MESHLINK_ERROR] = "\x1b[31mERROR", + [MESHLINK_CRITICAL] = "\x1b[31mCRITICAL", + }; + fprintf(stderr, "%s:\x1b[0m %s\n", levelstr[level], text); +} + +static void channel_receive(meshlink_handle_t *mesh, meshlink_channel_t *channel, const void *data, size_t len) { + if(!len) { + if(meshlink_errno) { + fprintf(stderr, "Error while reading data from %s: %s\n", channel->node->name, meshlink_strerror(meshlink_errno)); + } else { + fprintf(stderr, "Chat connection closed by %s\n", channel->node->name); + } + + channel->node->priv = NULL; + meshlink_channel_close(mesh, channel); + return; + } + + // TODO: we now have TCP semantics, don't expect exactly one message per receive call. + + fprintf(stderr, "%s says: ", channel->node->name); + fwrite(data, len, 1, stderr); + fputc('\n', stderr); +} + +static bool channel_accept(meshlink_handle_t *mesh, meshlink_channel_t *channel, uint16_t port, const void *data, size_t len) { + (void)data; + (void)len; + + // Only accept connections to the chat port + if(port != CHAT_PORT) { + fprintf(stderr, "Rejected incoming channel from '%s' to port %u\n", channel->node->name, port); + return false; + } + + fprintf(stderr, "Accepted incoming channel from '%s'\n", channel->node->name); + + // Remember the channel + channel->node->priv = channel; + + // Set the receive callback + meshlink_set_channel_receive_cb(mesh, channel, channel_receive); + + // Accept this channel + return true; +} + +static void channel_poll(meshlink_handle_t *mesh, meshlink_channel_t *channel, size_t len) { + (void)len; + + fprintf(stderr, "Channel to '%s' connected\n", channel->node->name); + meshlink_set_channel_poll_cb(mesh, channel, NULL); +} + +static void node_status(meshlink_handle_t *mesh, meshlink_node_t *node, bool reachable) { + (void)mesh; + + if(reachable) { + fprintf(stderr, "%s joined.\n", node->name); + } else { + fprintf(stderr, "%s left.\n", node->name); + } +} + +static meshlink_node_t **nodes; +static size_t nnodes; + +static void parse_command(meshlink_handle_t *mesh, char *buf) { + char *arg = strchr(buf, ' '); + char *arg1 = NULL; + meshlink_submesh_t *s = NULL; + static meshlink_submesh_t **submesh = NULL; + static size_t nmemb = 0; + size_t i; + + if(arg) { + *arg++ = 0; + + arg1 = strchr(arg, ' '); + + if(arg1) { + *arg1++ = 0; + } + + } + + if(!strcasecmp(buf, "invite")) { + char *invitation; + + if(!arg) { + fprintf(stderr, "/invite requires an argument!\n"); + return; + } + + if(arg1) { + + submesh = devtool_get_all_submeshes(mesh, submesh, &nmemb); + + if(!submesh || !nmemb) { + fprintf(stderr, "Group does not exist!\n"); + return; + } + + for(i = 0; i < nmemb; i++) { + if(!strcmp(arg1, submesh[i]->name)) { + s = submesh[i]; + break; + } else { + s = NULL; + } + } + + if(!s) { + fprintf(stderr, "Group is not yet creted!\n"); + return; + } + } + + invitation = meshlink_invite(mesh, s, arg); + + if(!invitation) { + fprintf(stderr, "Could not invite '%s': %s\n", arg, meshlink_strerror(meshlink_errno)); + return; + } + + fprintf(stderr, "Invitation for %s: %s\n", arg, invitation); + free(invitation); + } else if(!strcasecmp(buf, "canonical")) { + bool set; + char *host = NULL, *port = NULL; + + if(!arg) { + fprintf(stderr, "/canonical requires an argument!\n"); + return; + } + + if((0 == strncasecmp(arg, "-h", 2)) && (strlen(arg) > 2)) { + host = arg + 2; + } else if((0 == strncasecmp(arg, "-p", 2)) && (strlen(arg) > 2)) { + port = arg + 2; + } else { + fprintf(stderr, "Unknown argument: %s!\n", arg); + return; + } + + if(arg1) { + if((0 == strncasecmp(arg1, "-h", 2)) && (strlen(arg1) > 2)) { + host = arg1 + 2; + } else if((0 == strncasecmp(arg1, "-p", 2)) && (strlen(arg1) > 2)) { + port = arg1 + 2; + } else { + fprintf(stderr, "Unknown argument: %s!\n", arg1); + return; + } + } + + if(!host && !port) { + fprintf(stderr, "Unable to set Canonical address because no valid arguments are found!\n"); + return; + } + + set = meshlink_set_canonical_address(mesh, meshlink_get_self(mesh), host, port); + + if(!set) { + fprintf(stderr, "Could not set canonical address '%s:%s': %s\n", host, port, meshlink_strerror(meshlink_errno)); + return; + } + + fprintf(stderr, "Canonical address set as '%s:%s'\n", host, port); + } else if(!strcasecmp(buf, "group")) { + if(!arg) { + fprintf(stderr, "/group requires an argument!\n"); + return; + } + + if(!(s = meshlink_submesh_open(mesh, arg))) { + fprintf(stderr, "Could not create group: %s\n", meshlink_strerror(meshlink_errno)); + } else { + fprintf(stderr, "Group '%s' created!\n", s->name); + } + } else if(!strcasecmp(buf, "join")) { + if(!arg) { + fprintf(stderr, "/join requires an argument!\n"); + return; + } + + meshlink_stop(mesh); + + if(!meshlink_join(mesh, arg)) { + fprintf(stderr, "Could not join using invitation: %s\n", meshlink_strerror(meshlink_errno)); + } else { + fprintf(stderr, "Invitation accepted!\n"); + } + + if(!meshlink_start(mesh)) { + fprintf(stderr, "Could not restart MeshLink: %s\n", meshlink_strerror(meshlink_errno)); + exit(1); + } + } else if(!strcasecmp(buf, "kick")) { + if(!arg) { + fprintf(stderr, "/kick requires an argument!\n"); + return; + } + + meshlink_node_t *node = meshlink_get_node(mesh, arg); + + if(!node) { + fprintf(stderr, "Error looking up '%s': %s\n", arg, meshlink_strerror(meshlink_errno)); + return; + } + + meshlink_blacklist(mesh, node); + + fprintf(stderr, "Node '%s' blacklisted.\n", arg); + } else if(!strcasecmp(buf, "who")) { + meshlink_submesh_t *node_group = NULL; + + if(!arg) { + nodes = meshlink_get_all_nodes(mesh, nodes, &nnodes); + + if(!nnodes) { + fprintf(stderr, "Could not get list of nodes: %s\n", meshlink_strerror(meshlink_errno)); + } else { + fprintf(stderr, "%zu known nodes:\n", nnodes); + + for(size_t i = 0; i < nnodes; i++) { + fprintf(stderr, " %lu. %s", i, nodes[i]->name); + + if((node_group = meshlink_get_node_submesh(mesh, nodes[i]))) { + fprintf(stderr, "\t%s", node_group->name); + } + + fprintf(stderr, "\n"); + } + + fprintf(stderr, "\n"); + } + } else { + meshlink_node_t *node = meshlink_get_node(mesh, arg); + + if(!node) { + fprintf(stderr, "Error looking up '%s': %s\n", arg, meshlink_strerror(meshlink_errno)); + } else { + fprintf(stderr, "Node %s found", arg); + + if((node_group = meshlink_get_node_submesh(mesh, node))) { + fprintf(stderr, " in group %s", node_group->name); + } + + fprintf(stderr, "\n"); + } + } + } else if(!strcasecmp(buf, "listgroup")) { + if(!arg) { + fprintf(stderr, "/listgroup requires an argument!\n"); + return; + } + + submesh = devtool_get_all_submeshes(mesh, submesh, &nmemb); + + if(!submesh || !nmemb) { + fprintf(stderr, "Group does not exist!\n"); + return; + } + + for(i = 0; i < nmemb; i++) { + if(!strcmp(arg, submesh[i]->name)) { + s = submesh[i]; + break; + } else { + s = NULL; + } + } + + if(!s) { + fprintf(stderr, "Group %s does not exist!\n", arg); + return; + } + + nodes = meshlink_get_all_nodes_by_submesh(mesh, s, nodes, &nnodes); + + if(!nodes) { + fprintf(stderr, "Group %s does not contain any nodes!\n", arg); + return; + } + + if(nnodes <= 0) { + fprintf(stderr, "Could not get list of nodes for group %s: %s\n", arg, meshlink_strerror(meshlink_errno)); + } else { + fprintf(stderr, "%zu known nodes in group %s:", nnodes, arg); + + for(size_t i = 0; i < nnodes; i++) { + fprintf(stderr, " %s", nodes[i]->name); + } + + fprintf(stderr, "\n"); + } + } else if(!strcasecmp(buf, "quit")) { + fprintf(stderr, "Bye!\n"); + fclose(stdin); + } else if(!strcasecmp(buf, "help")) { + fprintf(stderr, + ": Send a message to the given node.\n" + " Subsequent messages don't need the : prefix.\n" + "/group Create a new group" + "/invite [submesh] Create an invitation for a new node.\n" + " Node joins either coremesh or submesh depending on submesh parameter.\n" + "/join Join an existing mesh using an invitation.\n" + "/kick Blacklist the given node.\n" + "/who [] List all nodes or show information about the given node.\n" + "/listgroup List all nodes in a given group.\n" + "/canonical -h -p Set Canonical address to be present in invitation.\n" + " Any one of two options an be specified. Atleast one option must be present\n" + "/quit Exit this program.\n" + ); + } else { + fprintf(stderr, "Unknown command '/%s'\n", buf); + } +} + +static void parse_input(meshlink_handle_t *mesh, char *buf) { + static meshlink_node_t *destination; + size_t len; + + if(!buf) { + return; + } + + // Remove newline. + + len = strlen(buf); + + if(len && buf[len - 1] == '\n') { + buf[--len] = 0; + } + + if(len && buf[len - 1] == '\r') { + buf[--len] = 0; + } + + // Ignore empty lines. + + if(!len) { + return; + } + + // Commands start with '/' + + if(*buf == '/') { + parse_command(mesh, buf + 1); + return; + } + + // Lines in the form "name: message..." set the destination node. + + char *msg = buf; + char *colon = strchr(buf, ':'); + + if(colon) { + *colon = 0; + msg = colon + 1; + + if(*msg == ' ') { + msg++; + } + + destination = meshlink_get_node(mesh, buf); + + if(!destination) { + fprintf(stderr, "Error looking up '%s': %s\n", buf, meshlink_strerror(meshlink_errno)); + return; + } + } + + if(!destination) { + fprintf(stderr, "Who are you talking to? Write 'name: message...'\n"); + return; + } + + // We want to have one channel per node. + // We keep the pointer to the meshlink_channel_t in the priv field of that node. + meshlink_channel_t *channel = destination->priv; + + if(!channel) { + fprintf(stderr, "Opening chat channel to '%s'\n", destination->name); + channel = meshlink_channel_open(mesh, destination, CHAT_PORT, channel_receive, NULL, 0); + + if(!channel) { + fprintf(stderr, "Could not create channel to '%s': %s\n", destination->name, meshlink_strerror(meshlink_errno)); + return; + } + + destination->priv = channel; + meshlink_set_channel_poll_cb(mesh, channel, channel_poll); + } + + if(!meshlink_channel_send(mesh, channel, msg, strlen(msg))) { + fprintf(stderr, "Could not send message to '%s': %s\n", destination->name, meshlink_strerror(meshlink_errno)); + return; + } + + fprintf(stderr, "Message sent to '%s'.\n", destination->name); +} + +int main(int argc, char *argv[]) { + const char *confbase = ".chat"; + const char *nick = NULL; + char buf[1024]; + + if(argc > 1) { + confbase = argv[1]; + } + + if(argc > 2) { + nick = argv[2]; + } + + meshlink_set_log_cb(NULL, MESHLINK_DEBUG, log_message); + + meshlink_handle_t *mesh = meshlink_open(confbase, nick, "chat", DEV_CLASS_STATIONARY); + + if(!mesh) { + fprintf(stderr, "Could not open MeshLink: %s\n", meshlink_strerror(meshlink_errno)); + return 1; + } + + meshlink_set_node_status_cb(mesh, node_status); + meshlink_set_log_cb(mesh, MESHLINK_INFO, log_message); + + // Set the channel accept callback. This implicitly turns on channels for all nodes. + // This replaces the call to meshlink_set_receive_cb(). + meshlink_set_channel_accept_cb(mesh, channel_accept); + + if(!meshlink_start(mesh)) { + fprintf(stderr, "Could not start MeshLink: %s\n", meshlink_strerror(meshlink_errno)); + return 1; + } + + fprintf(stderr, "Chat started.\nType /help for a list of commands.\n"); + + while(fgets(buf, sizeof(buf), stdin)) { + parse_input(mesh, buf); + } + + fprintf(stderr, "Chat stopping.\n"); + + meshlink_stop(mesh); + meshlink_close(mesh); + + return 0; +} -- 2.39.2