add socket snippet

Socket_CAN/socketcan0

@@ -0,0 +1,4 @@
+#!/bin/sh
+
+ip link set can0 type can bitrate 100000 triple-sampling on
+ifconfig can0 up

Socket_snippet/Makefile

@@ -0,0 +1,45 @@
+# run `make DEF=...` to add extra defines
+PROGRAM := socket
+LDFLAGS := -fdata-sections -ffunction-sections -Wl,--gc-sections -Wl,--discard-all
+LDFLAGS += -lusefull_macros -lm -L/usr/local/lib/
+SRCS := $(wildcard *.c)
+DEFINES := $(DEF) -D_GNU_SOURCE -D_XOPEN_SOURCE=1111
+OBJDIR := mk
+CFLAGS += -O3 -Wno-trampolines -std=gnu99
+OBJS := $(addprefix $(OBJDIR)/, $(SRCS:%.c=%.o))
+DEPS := $(OBJS:.o=.d)
+CC = gcc
+#CXX = g++
+
+
+all : $(PROGRAM)
+
+debug: CFLAGS += -DEBUG -Werror -Wall -Wextra 
+debug: all
+
+$(OBJS): $(OBJDIR)
+
+$(PROGRAM) : $(OBJS)
+	@echo -e "\t\tLD $(PROGRAM)"
+	$(CC) $(OBJS) $(LDFLAGS) -o $(PROGRAM)
+
+$(OBJDIR):
+	mkdir $(OBJDIR)
+
+ifneq ($(MAKECMDGOALS),clean)
+-include $(DEPS)
+endif
+
+$(OBJDIR)/%.o: %.c
+	@echo -e "\t\tCC $<"
+	$(CC) $< -MD -c $(CFLAGS) $(DEFINES) -o $@ 
+
+clean:
+	@echo -e "\t\tCLEAN"
+	@rm -f $(OBJS) $(DEPS)
+	@rmdir $(OBJDIR) 2>/dev/null || true
+
+xclean: clean
+	@rm -f $(PROGRAM)
+
+.PHONY: clean xclean

Socket_snippet/Readme.md

@@ -0,0 +1,7 @@
+Socket server and client snippet
+================================
+
+This snippet allows to create some utilities than can be run both in client or server mode.
+The sockets are **local** TCP or UNIX sockets. Server-side polling use `poll()`.
+
+The pieces of user code may be in comments marked `USERCODE`

Socket_snippet/client.c

@@ -0,0 +1,120 @@
+/*
+ * This file is part of the socksnippet project.
+ * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+// client-side functions
+#include <stdio.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <usefull_macros.h>
+
+#include "client.h"
+#include "socket.h"
+
+/**
+ * @brief processData - process here some actions and make messages for server
+ * @param buf (o) - buffer for answer
+ * @param l - max length of buf
+ * @return amount of answer bytes
+ */
+static int process_data(char *buf, int l){
+    if(!buf || !l) return 0;
+    /* USERCODE: get here some data to send */
+    static double t0 = 0.;
+    if(dtime() - t0 > 1.){
+        t0 = dtime();
+        // send random commands each 1 second
+        int x = rand() % 600;
+        const char *cmd = NULL;
+        if(x < 100) cmd = "time";
+        else if(x < 200) cmd = "getval1";
+        else if(x < 300) cmd = "getval2";
+        else if(x < 400) cmd = "ping";
+        if(cmd) snprintf(buf, l, "%s", cmd);
+        else{
+            if(x < 500) snprintf(buf, l, "setval1=%d", rand() & 0xff);
+            else snprintf(buf, l, "setval2=%d", rand() & 0xff);
+        }
+        return strlen(buf);
+    }
+    return 0;
+}
+
+/**
+ * @brief process_server_message - parse messages from server and make an answer
+ * @param buf (io) - incoming message (the answer will be in this buffer)
+ * @param l - buff max length
+ * @return amount of answer bytes
+ */
+static int process_server_message(char *buf, int l){
+    /* USERCODE inside this funtion */
+    if(!buf || !l) return 0;
+    // just show on screen
+    green("SERVER send: %s\n", buf);
+    return 0;
+}
+
+
+/**
+ * check data from  fd (polling function for client)
+ * @param fd - file descriptor
+ * @return 0 in case of timeout, 1 in case of fd have data, -1 if error
+ */
+static int canberead(int fd){
+    fd_set fds;
+    struct timeval timeout;
+    timeout.tv_sec = 0;
+    timeout.tv_usec = 100;
+    FD_ZERO(&fds);
+    FD_SET(fd, &fds);
+    do{
+        int rc = select(fd+1, &fds, NULL, NULL, &timeout);
+        if(rc < 0){
+            if(errno != EINTR){
+                LOGWARN("select()");
+                WARN("select()");
+                return -1;
+            }
+            continue;
+        }
+        break;
+    }while(1);
+    if(FD_ISSET(fd, &fds)){
+        //DBG("FD_ISSET");
+        return 1;
+    }
+    return 0;
+}
+
+void client(int sock){
+    char buf[BUFLEN];
+    while(1){
+        int l = process_data(buf, BUFLEN-1);
+        if(l) sendmessage(sock, buf, l);
+        if(1 != canberead(sock)) continue;
+        int n = read(sock, buf, BUFLEN-1);
+        if(n == 0){
+            WARNX("Server disconnected");
+            signals(0);
+        }
+        buf[n] = 0;
+        DBG("Got from server: %s", buf);
+        LOGMSG("Got from server: %s", buf);
+        l = process_server_message(buf, n);
+        if(l) sendmessage(sock, buf, l);
+    }
+}

Socket_snippet/client.h

@@ -0,0 +1,26 @@
+/*
+ * This file is part of the socksnippet project.
+ * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef CLIENT_H__
+#define CLIENT_H__
+
+// client-side functions
+void client(int fd);
+
+#endif // CLIENT_H__

Socket_snippet/cmdlnopts.c

@@ -0,0 +1,83 @@
+/*
+ * This file is part of the socksnippet project.
+ * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+#include <stdarg.h>
+#include <stdio.h>
+
+#include "cmdlnopts.h"
+#include "usefull_macros.h"
+
+// default PID filename:
+#define DEFAULT_PIDFILE     "/tmp/usbsock.pid"
+
+static int help;
+static glob_pars G = {
+    .pidfile = DEFAULT_PIDFILE,
+};
+glob_pars *GP = &G;
+
+/*
+ * Define command line options by filling structure:
+ *  name        has_arg     flag    val     type        argptr              help
+*/
+static myoption cmdlnopts[] = {
+    {"help",    NO_ARGS,    NULL,   'h',    arg_int,    APTR(&help),        _("show this help")},
+    {"logfile", NEED_ARG,   NULL,   'l',    arg_string, APTR(&G.logfile),   _("file to save logs (default: none)")},
+    {"pidfile", NEED_ARG,   NULL,   'p',    arg_string, APTR(&G.pidfile),   _("pidfile (default: " DEFAULT_PIDFILE ")")},
+    {"client",  NO_ARGS,    NULL,   'c',    arg_int,    APTR(&G.client),    _("run as client")},
+    {"path",    NEED_ARG,   NULL,   'N',    arg_string, APTR(&G.path),      _("UNIX socket path/name (start from \\0 for no files)")},
+    {"port",    NEED_ARG,   NULL,   'P',    arg_string, APTR(&G.port),      _("port to connect (for local TCP socket)")},
+    {"verbose", NO_ARGS,    NULL,   'v',    arg_none,   APTR(&G.verbose),   _("increase log verbose level (default: LOG_WARN) and messages (default: none)")},
+   end_option
+};
+
+/**
+ * Parse command line options and return dynamically allocated structure
+ *      to global parameters
+ * @param argc - copy of argc from main
+ * @param argv - copy of argv from main
+ * @return allocated structure with global parameters
+ */
+void parse_args(int argc, char **argv){
+    int i;
+    size_t hlen = 1024;
+    char helpstring[1024], *hptr = helpstring;
+    snprintf(hptr, hlen, "Usage: %%s [args]\n\n\tWhere args are:\n");
+    // format of help: "Usage: progname [args]\n"
+    change_helpstring(helpstring);
+    // parse arguments
+    parseargs(&argc, &argv, cmdlnopts);
+    for(i = 0; i < argc; i++)
+        printf("Ignore parameter\t%s\n", argv[i]);
+    if(help) showhelp(-1, cmdlnopts);
+}
+
+/**
+ * @brief verbose - print additional messages depending of G.verbose (add '\n' at end)
+ * @param levl - message level
+ * @param fmt  - message
+ */
+void verbose(int levl, const char *fmt, ...){
+    va_list ar;
+    if(levl > G.verbose) return;
+    va_start(ar, fmt);
+    vprintf(fmt, ar);
+    va_end(ar);
+    printf("\n");
+}

Socket_snippet/cmdlnopts.h

@@ -0,0 +1,40 @@
+/*
+ * This file is part of the socksnippet project.
+ * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef CMDLNOPTS_H__
+#define CMDLNOPTS_H__
+
+/*
+ * here are some typedef's for global data
+ */
+typedef struct{
+    char *pidfile;          // name of PID file
+    char *logfile;          // logging to this file
+    char *path;             // path to UNIX-socket file
+    char *port;             // local TCP socket port
+    int verbose;            // verbose level: for messages & logging
+    int client;             // ==1 if application runs in client mode
+} glob_pars;
+
+extern glob_pars *GP;
+
+void parse_args(int argc, char **argv);
+void verbose(int levl, const char *fmt, ...);
+
+#endif // CMDLNOPTS_H__

Socket_snippet/main.c

@@ -0,0 +1,108 @@
+/*
+ * This file is part of the socksnippet project.
+ * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <signal.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <usefull_macros.h>
+
+#include "cmdlnopts.h"
+#include "socket.h"
+
+static pid_t childpid = 0;
+static int isserver = 1;
+
+void signals(int sig){
+    if(childpid){ // slave process
+        DBG("Child killed with sig=%d", sig);
+        LOGWARN("Child killed with sig=%d", sig);
+        exit(sig);
+    }
+    // master process
+    DBG("Master process");
+    if(sig){
+        DBG("Exit with signal %d", sig);
+        signal(sig, SIG_IGN);
+        LOGERR("Exit with signal %d", sig);
+    }else LOGERR("Exit");
+    if(GP->pidfile && isserver){
+        DBG("Unlink pid file");
+        unlink(GP->pidfile);
+    }
+    exit(sig);
+}
+
+int main(int argc, char **argv){
+    char *self = strdup(argv[0]);
+    initial_setup();
+    parse_args(argc, argv);
+    if(GP->logfile){
+        int lvl = LOGLEVEL_WARN + GP->verbose;
+        DBG("level = %d", lvl);
+        if(lvl > LOGLEVEL_ANY) lvl = LOGLEVEL_ANY;
+        verbose(1, "Log file %s @ level %d\n", GP->logfile, lvl);
+        OPENLOG(GP->logfile, lvl, 1);
+        if(!globlog) WARNX("Can't create log file");
+    }
+    if(GP->client) isserver = 0;
+    if(GP->port){
+        if(GP->path){
+            WARNX("Options `port` and `path` can't be used together! Point `port` for TCP socket or `path` for UNIX.");
+            return 1;
+        }
+        int port = atoi(GP->port);
+        if(port < PORTN_MIN || port > PORTN_MAX){
+            WARNX("Wrong port value: %d", port);
+            return 1;
+        }
+    }else if(!GP->path) ERRX("You should point option `port` or `path`!");
+
+    if(isserver) check4running(self, GP->pidfile);
+    // signal reactions:
+    signal(SIGTERM, signals); // kill (-15) - quit
+    signal(SIGHUP, SIG_IGN);  // hup - ignore
+    signal(SIGINT, signals);  // ctrl+C - quit
+    signal(SIGQUIT, signals); // ctrl+\ - quit
+    signal(SIGTSTP, SIG_IGN); // ignore ctrl+Z
+    LOGMSG("Started");
+#ifndef EBUG
+    if(isserver){
+        unsigned int pause = 5;
+        while(1){
+            childpid = fork();
+            if(childpid){ // master
+                double t0 = dtime();
+                LOGMSG("Created child with pid %d", childpid);
+                wait(NULL);
+                LOGWARN("Child %d died", childpid);
+                if(dtime() - t0 < 1.) pause += 5;
+                else pause = 1;
+                if(pause > 900) pause = 900;
+                sleep(pause); // wait a little before respawn
+            }else{ // slave
+                prctl(PR_SET_PDEATHSIG, SIGTERM); // send SIGTERM to child when parent dies
+                break;
+            }
+        }
+    }
+#endif
+    if(GP->path) return start_socket(isserver, GP->path, FALSE);
+    if(GP->port) return start_socket(isserver, GP->port, TRUE);
+}

Socket_snippet/server.c

@@ -0,0 +1,150 @@
+/*
+ * This file is part of the socksnippet project.
+ * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <netdb.h>
+#include <poll.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <usefull_macros.h>
+
+#include "server.h"
+#include "socket.h"
+
+// server-side functions
+
+// command handlers
+hresult pinghandler(int fd, _U_ const char *key, _U_ const char *val){
+    sendstrmessage(fd, "PING");
+    return RESULT_SILENCE;
+}
+
+static int sendtime = 0;
+hresult timehandler(_U_ int fd, _U_ const char *key, _U_ const char *val){
+    sendtime = 1;
+    return RESULT_OK;
+}
+
+static int value1 = 0, value2 = 0;
+hresult valsethandler(_U_ int fd, const char *key, const char *val){
+    if(!val || !*val) return RESULT_BADVAL;
+    int i = atoi(val);
+    if(i < -65535 || i > 65535) return RESULT_BADVAL;
+    if(strcmp(key, "setval1") == 0) value1 = i;
+    else value2 = i;
+    return RESULT_OK;
+}
+hresult valgethandler(int fd, const char *key, _U_ const char *val){
+    char buf[32];
+    if(strcmp(key, "getval1") == 0) snprintf(buf, 32, "VAL1=%d", value1);
+    else snprintf(buf, 32, "VAL2=%d", value2);
+    sendstrmessage(fd, buf);
+    return RESULT_SILENCE;
+}
+
+/*
+hresult handler(_U_ int fd, _U_ const char *key, _U_ const char *val){
+    ;
+}
+*/
+
+static handleritem items[] = {
+    {pinghandler, "ping"},
+    {timehandler, "time"},
+    {valsethandler, "setval1"},
+    {valsethandler, "setval2"},
+    {valgethandler, "getval1"},
+    {valgethandler, "getval2"},
+    {NULL, NULL},
+};
+
+/**
+ * @brief processData - process here some actions and make messages for all clients
+ * @param buf (o) - buffer for answer
+ * @param l - max length of buf
+ * @return amount of answer bytes
+ */
+static int process_data(char *buf, int l){
+    if(!buf || !l) return 0;
+    /* USERCODE: get here some data to send all clients */
+    if(sendtime){
+        snprintf(buf, l, "TIME=%.2f", dtime());
+        sendtime = 0;
+        return strlen(buf);
+    }
+    return 0;
+}
+
+#define CLBUFSZ     BUFSIZ
+
+void server(int sock){
+    if(listen(sock, MAXCLIENTS) == -1){
+        WARN("listen");
+        LOGWARN("listen");
+        return;
+    }
+    int nfd = 1; // only one socket @start
+    struct pollfd poll_set[MAXCLIENTS+1];
+    char buffers[MAXCLIENTS][CLBUFSZ]; // buffers for data reading
+    bzero(poll_set, sizeof(poll_set));
+    // ZERO - listening server socket
+    poll_set[0].fd = sock;
+    poll_set[0].events = POLLIN;
+    while(1){
+        poll(poll_set, nfd, 1); // max timeout - 1ms
+        if(poll_set[0].revents & POLLIN){ // check main for accept()
+            struct sockaddr_in addr;
+            socklen_t len = sizeof(addr);
+            int client = accept(sock, (struct sockaddr*)&addr, &len);
+            DBG("New connection");
+            LOGMSG("SERVER got connection, fd=%d", client);
+            if(nfd == MAXCLIENTS + 1){
+                LOGWARN("Max amount of connections, disconnect fd=%d", client);
+                WARNX("Limit of connections reached");
+                close(client);
+            }else{
+                memset(&poll_set[nfd], 0, sizeof(struct pollfd));
+                poll_set[nfd].fd = client;
+                poll_set[nfd].events = POLLIN;
+                ++nfd;
+            }
+        }
+        char buff[BUFLEN];
+        int l = 0;
+        // process some data & send messages to ALL
+        if((l = process_data(buff, BUFLEN-1))){
+            DBG("Send to %d clients", nfd - 1);
+            for(int i = 1; i < nfd; ++i)
+                sendmessage(poll_set[i].fd, buff, l);
+        }
+        // scan connections
+        for(int fdidx = 1; fdidx < nfd; ++fdidx){
+            if((poll_set[fdidx].revents & POLLIN) == 0) continue;
+            int fd = poll_set[fdidx].fd;
+            if(!processData(fd, items, buffers[fdidx-1], CLBUFSZ)){ // socket closed
+                DBG("Client fd=%d disconnected", fd);
+                LOGMSG("SERVER client fd=%d disconnected", fd);
+                buffers[fdidx-1][0] = 0; // clear rest of data in buffer
+                close(fd);
+                // move last FD to current position
+                poll_set[fdidx] = poll_set[nfd - 1];
+                --nfd;
+            }
+        }
+    }
+}

Socket_snippet/server.h

@@ -0,0 +1,26 @@
+/*
+ * This file is part of the socksnippet project.
+ * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef SERVER_H__
+#define SERVER_H__
+
+// server-side functions
+void server(int fd);
+
+#endif // SERVER_H__

Socket_snippet/socket.c

@@ -0,0 +1,213 @@
+/*
+ * This file is part of the socksnippet project.
+ * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <ctype.h> // isspace
+#include <netdb.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/un.h>  // unix socket
+#include <usefull_macros.h>
+
+#include "cmdlnopts.h"
+#include "client.h"
+#include "server.h"
+#include "socket.h"
+
+/**
+ * @brief start_socket - create socket and run client or server
+ * @param isserver  - TRUE for server, FALSE for client
+ * @param path      - UNIX-socket path or local INET socket port
+ * @param isnet     - TRUE for INET socket, FALSE for UNIX
+ * @return 0 if OK
+ */
+int start_socket(int isserver, char *path, int isnet){
+    if(!path) return 1;
+    DBG("path/port: %s", path);
+    int sock = -1;
+    struct addrinfo hints = {0}, *res;
+    struct sockaddr_un unaddr = {0};
+    if(isnet){
+        DBG("Network socket");
+        hints.ai_family = AF_INET;
+        hints.ai_socktype = SOCK_STREAM;
+        hints.ai_flags = AI_PASSIVE;
+        if(getaddrinfo("127.0.0.1", path, &hints, &res) != 0){
+            ERR("getaddrinfo");
+        }
+    }else{
+        DBG("UNIX socket");
+        char apath[128];
+        if(*path == 0){
+            DBG("convert name");
+            apath[0] = 0;
+            strncpy(apath+1, path+1, 126);
+        }else if(strncmp("\\0", path, 2) == 0){
+            DBG("convert name");
+            apath[0] = 0;
+            strncpy(apath+1, path+2, 126);
+        }else strcpy(apath, path);
+        unaddr.sun_family = AF_UNIX;
+        hints.ai_addr = (struct sockaddr*) &unaddr;
+        hints.ai_addrlen = sizeof(unaddr);
+        memcpy(unaddr.sun_path, apath, 106); // if sun_path[0] == 0 we don't create a file
+        hints.ai_family = AF_UNIX;
+        hints.ai_socktype = SOCK_SEQPACKET;
+        res = &hints;
+    }
+    for(struct addrinfo *p = res; p; p = p->ai_next){
+        if((sock = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) < 0){ // or SOCK_STREAM?
+            LOGWARN("socket()");
+            WARN("socket()");
+            continue;
+        }
+        if(isserver){
+            int reuseaddr = 1;
+            if(setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &reuseaddr, sizeof(int)) == -1){
+                LOGWARN("setsockopt()");
+                WARN("setsockopt()");
+                close(sock); sock = -1;
+                continue;
+            }
+            if(bind(sock, p->ai_addr, p->ai_addrlen) == -1){
+                LOGWARN("bind()");
+                WARN("bind()");
+                close(sock); sock = -1;
+                continue;
+            }
+            int enable = 1;
+            if(ioctl(sock, FIONBIO, (void *)&enable) < 0){ // make socket nonblocking
+                LOGERR("Can't make socket nonblocking");
+                ERRX("ioctl()");
+            }
+        }else{
+            if(connect(sock, p->ai_addr, p->ai_addrlen) == -1){
+                LOGWARN("connect()");
+                WARN("connect()");
+                close(sock); sock = -1;
+            }
+        }
+        break;
+    }
+    if(sock < 0){
+        LOGERR("Can't open socket");
+        ERRX("Can't open socket");
+    }
+    if(isnet) freeaddrinfo(res);
+    if(isserver) server(sock);
+    else client(sock);
+    close(sock);
+    signals(0);
+    return 0;
+}
+
+// simple wrapper over write: add missed newline and log data
+void sendmessage(int fd, const char *msg, int l){
+    if(fd < 1 || !msg || l < 1) return;
+    DBG("send to fd %d: %s [%d]", fd, msg, l);
+    char *tmpbuf = MALLOC(char, l+1);
+    memcpy(tmpbuf, msg, l);
+    if(msg[l-1] != '\n') tmpbuf[l++] = '\n';
+    if(l != write(fd, tmpbuf, l)){
+        LOGWARN("write()");
+        WARN("write()");
+    }else{
+        if(globlog){ // logging turned ON
+            tmpbuf[l-1] = 0; // remove trailing '\n' for logging
+            LOGMSG("SEND to fd %d: %s", fd, tmpbuf);
+        }
+    }
+    FREE(tmpbuf);
+}
+void sendstrmessage(int fd, const char *msg){
+    if(fd < 1 || !msg) return;
+    int l = strlen(msg);
+    sendmessage(fd, msg, l);
+}
+
+// text messages for `hresult`
+static const char *resmessages[] = {
+    [RESULT_OK] = "OK",
+    [RESULT_FAIL] = "FAIL",
+    [RESULT_BADKEY] = "BADKEY",
+    [RESULT_BADVAL] = "BADVAL",
+    [RESULT_SILENCE] = "",
+};
+
+const char *hresult2str(hresult r){
+    if(r >= RESULT_NUM) return "BADRESULT";
+    return resmessages[r];
+}
+
+// parse string of data (command or key=val)
+// the CONTENT of buffer `str` WILL BE BROKEN!
+static void parsestring(int fd, handleritem *handlers, char *str){
+    if(fd < 1 || !handlers || !handlers->key || !str || !*str) return;
+    DBG("Got string %s", str);
+    // remove starting spaces in key
+    while(isspace(*str)) ++str;
+    char *val = strchr(str, '=');
+    if(val){ // get value: remove starting spaces in val
+        *val++ = 0;
+        while(isspace(*val)) ++val;
+    }
+    // remove trailing spaces in key
+    char *e = str + strlen(str) - 1; // last key symbol
+    while(isspace(*e) && e > str) --e;
+    e[1] = 0;
+    // now we have key (`str`) and val (or NULL)
+    DBG("key=%s, val=%s", str, val);
+    for(handleritem *h = handlers; h->handler; ++h){
+        if(strcmp(str, h->key) == 0){ // found command
+            if(h->handler){
+                hresult r = h->handler(fd, str, val);
+                sendstrmessage(fd, hresult2str(r));
+            }else sendstrmessage(fd, resmessages[RESULT_FAIL]);
+            return;
+        }
+    }
+    sendstrmessage(fd, resmessages[RESULT_BADKEY]);
+}
+
+/**
+ * @brief processData - read (if available) data from fd and run processing, sending to fd messages for each command
+ * @param fd        - socket file descriptor
+ * @param handlers  - NULL-terminated array of handlers
+ * @param buf (io)   - zero-terminated buffer for storing rest of data (without newline), its content will be changed
+ * @param buflen    - its length
+ * @return FALSE if client closed (nothing to read)
+ */
+int processData(int fd, handleritem *handlers, char *buf, int buflen){
+    int curlen = strlen(buf);
+    if(curlen == buflen-1) curlen = 0; // buffer overflow - clear old content
+    ssize_t rd = read(fd, buf + curlen, buflen-1 - curlen);
+    if(rd <= 0) return FALSE;
+    DBG("got %s[%zd] from %d", buf, rd, fd);
+    char *restofdata = buf, *eptr = buf + curlen + rd;
+    *eptr = 0;
+    do{
+        char *nl = strchr(restofdata, '\n');
+        if(!nl) break;
+        *nl++ = 0;
+        parsestring(fd, handlers, restofdata);
+        restofdata = nl;
+        DBG("rest of data: %s", restofdata);
+    }while(1);
+    if(restofdata != buf) memmove(buf, restofdata, eptr - restofdata + 1);
+    return TRUE;
+}

Socket_snippet/socket.h

@@ -0,0 +1,56 @@
+/*
+ * This file is part of the socksnippet project.
+ * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef SERSOCK_H__
+#define SERSOCK_H__
+
+// max & min TCP socket port number
+#define PORTN_MAX   (65535)
+#define PORTN_MIN   (1024)
+
+#define BUFLEN      (1024)
+// Max amount of connections
+#define MAXCLIENTS  (30)
+
+typedef enum{
+    RESULT_OK,      // all OK
+    RESULT_FAIL,    // failed running command
+    RESULT_BADVAL,  // bad key's value
+    RESULT_BADKEY,  // bad key
+    RESULT_SILENCE, // send nothing to client
+    RESULT_NUM
+} hresult;
+
+const char *hresult2str(hresult r);
+
+// fd - socket fd to send private messages, key, val - key and its value
+typedef hresult (*mesghandler)(int fd, const char *key, const char *val);
+
+typedef struct{
+    mesghandler handler;
+    const char *key;
+} handleritem;
+
+int start_socket(int server, char *path, int isnet);
+void sendmessage(int fd, const char *msg, int l);
+void sendstrmessage(int fd, const char *msg);
+
+int processData(int fd, handleritem *handlers, char *buf, int buflen);
+
+#endif // SERSOCK_H__

Socket_snippet/socksnippet.cflags

@@ -0,0 +1 @@
+-std=c17

Socket_snippet/socksnippet.config

@@ -0,0 +1,6 @@
+// Add predefined macros for your project here. For example:
+// #define THE_ANSWER 42
+#define EBUG
+#define _GNU_SOURCE
+#define _XOPEN_SOURCE=1111
+

Socket_snippet/socksnippet.creator

@@ -0,0 +1 @@
+[General]

Socket_snippet/socksnippet.creator.user

@@ -0,0 +1,163 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE QtCreatorProject>
+<!-- Written by QtCreator 6.0.0, 2022-02-02T17:26:10. -->
+<qtcreator>
+ <data>
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+  <value type="int">0</value>
+ </data>
+ <data>
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+  <valuemap type="QVariantMap">
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+   <value type="bool" key="EditorConfiguration.AutoSpacesForTabs">false</value>
+   <value type="bool" key="EditorConfiguration.CamelCaseNavigation">true</value>
+   <valuemap type="QVariantMap" key="EditorConfiguration.CodeStyle.0">
+    <value type="QString" key="language">Cpp</value>
+    <valuemap type="QVariantMap" key="value">
+     <value type="QByteArray" key="CurrentPreferences">CppGlobal</value>
+    </valuemap>
+   </valuemap>
+   <valuemap type="QVariantMap" key="EditorConfiguration.CodeStyle.1">
+    <value type="QString" key="language">QmlJS</value>
+    <valuemap type="QVariantMap" key="value">
+     <value type="QByteArray" key="CurrentPreferences">QmlJSGlobal</value>
+    </valuemap>
+   </valuemap>
+   <value type="int" key="EditorConfiguration.CodeStyle.Count">2</value>
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+   <value type="bool" key="EditorConfiguration.MouseNavigation">true</value>
+   <value type="int" key="EditorConfiguration.PaddingMode">1</value>
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+   <value type="bool" key="EditorConfiguration.ShowMargin">false</value>
+   <value type="int" key="EditorConfiguration.SmartBackspaceBehavior">1</value>
+   <value type="bool" key="EditorConfiguration.SmartSelectionChanging">true</value>
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+   <value type="int" key="EditorConfiguration.TabKeyBehavior">0</value>
+   <value type="int" key="EditorConfiguration.TabSize">8</value>
+   <value type="bool" key="EditorConfiguration.UseGlobal">true</value>
+   <value type="bool" key="EditorConfiguration.UseIndenter">false</value>
+   <value type="int" key="EditorConfiguration.Utf8BomBehavior">2</value>
+   <value type="bool" key="EditorConfiguration.addFinalNewLine">true</value>
+   <value type="bool" key="EditorConfiguration.cleanIndentation">true</value>
+   <value type="bool" key="EditorConfiguration.cleanWhitespace">true</value>
+   <value type="QString" key="EditorConfiguration.ignoreFileTypes">*.md, *.MD, Makefile</value>
+   <value type="bool" key="EditorConfiguration.inEntireDocument">true</value>
+   <value type="bool" key="EditorConfiguration.skipTrailingWhitespace">true</value>
+  </valuemap>
+ </data>
+ <data>
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+  <valuemap type="QVariantMap">
+   <valuemap type="QVariantMap" key="ClangTools">
+    <value type="bool" key="ClangTools.AnalyzeOpenFiles">true</value>
+    <value type="bool" key="ClangTools.BuildBeforeAnalysis">true</value>
+    <value type="QString" key="ClangTools.DiagnosticConfig">Builtin.DefaultTidyAndClazy</value>
+    <value type="int" key="ClangTools.ParallelJobs">4</value>
+    <valuelist type="QVariantList" key="ClangTools.SelectedDirs"/>
+    <valuelist type="QVariantList" key="ClangTools.SelectedFiles"/>
+    <valuelist type="QVariantList" key="ClangTools.SuppressedDiagnostics"/>
+    <value type="bool" key="ClangTools.UseGlobalSettings">true</value>
+   </valuemap>
+   <valuemap type="QVariantMap" key="CppEditor.QuickFix">
+    <value type="bool" key="UseGlobalSettings">true</value>
+   </valuemap>
+  </valuemap>
+ </data>
+ <data>
+  <variable>ProjectExplorer.Project.Target.0</variable>
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+   <value type="QString" key="ProjectExplorer.ProjectConfiguration.DefaultDisplayName">Desktop</value>
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+   <valuemap type="QVariantMap" key="ProjectExplorer.Target.BuildConfiguration.0">
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+    <valuemap type="QVariantMap" key="ProjectExplorer.BuildConfiguration.BuildStepList.0">
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+      </valuelist>
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+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Default</value>
+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">GenericProjectManager.GenericBuildConfiguration</value>
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+    </valuemap>
+    <value type="int" key="ProjectExplorer.BuildConfiguration.BuildStepListCount">1</value>
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+   </valuemap>
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+    <value type="bool" key="RunConfiguration.UseCppDebugger">false</value>
+    <value type="bool" key="RunConfiguration.UseCppDebuggerAuto">true</value>
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+  <value type="int">22</value>
+ </data>
+ <data>
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+  <value type="int">22</value>
+ </data>
+</qtcreator>

Socket_snippet/socksnippet.cxxflags

@@ -0,0 +1 @@
+-std=c++17

Socket_snippet/socksnippet.files

@@ -0,0 +1,9 @@
+client.c
+client.h
+cmdlnopts.c
+cmdlnopts.h
+main.c
+server.c
+server.h
+socket.c
+socket.h

Socket_snippet/socksnippet.includes

@@ -0,0 +1 @@
+.

Socket_snippet/testcommands

@@ -0,0 +1,11 @@
+     time         
+    getval1                   
+           setval1       =             56
+       getval2   
+           setval2    =        189
+     getval1       =  asdf 
+       getval2 =                       000000asdffd fdassdf fda
+                                                          time
+         a
+   getval1
+getval2