DNS resolution: can specify hostname via -H or -s

CHANGELOG

@@ -1,5 +1,6 @@
 2018-05-16
 
+    - [FEATURE] DNS resolution
     - [BUGFIX] Frame insertion mis-ID as overlap instead of dup
     - http_client: fix priority range generated by -E flag
 

CONTRIBUTORS.txt

@@ -6,7 +6,7 @@ to the LiteSpeed Client Library:
     - Amol Desphande -- Windows support
     - Alexis La Goutte -- Travis-CI integration
     - Bernhard Jaeger -- DNS Resolution
-    
+
 Thank you!
 
 We welcome contributions in any form -- patches, issues, pull requests.

EXAMPLES.txt

@@ -9,21 +9,17 @@ Usage Examples
 
 Fetch Google's home page:
 
-    ./http_client -H www.google.com -s 443 -p /
+    ./http_client -s www.google.com -p /
 
-In the example above, -H specifies the domain; it is also used as the value
+The default port number is 443, but it can be specified after colon
-of SNI paramater in the handshake.
+using the -s flag.  The value of the `host' header as well as the SNI
+value defaults to the host part of the -s option.  -H option can be
+used to override it.  For example:
 
-The port number is specified using the -s flag.
+    ./http_client -H www.youtube.com -s www.google.com:443 -p / -M HEAD
-The ip adress is determined automatically.
-The -6 flag tells the program to use IPv6 instead of IPv4. 
-Note that -6 must be used before -s in order to work.
 
-You can also specify a certain ip-address with the -s command.
+The host part can be an IP address.  Both IPv4 and IPv6 are supported.
-Note that this example won't work everywhere since google has a lot of different ips. 
+See ./http_client -h for a (long) list of different flags.
-You have to look up the correct one for yourself.
-
-    ./http_client -H www.google.com -s 172.217.22.4:443 -p /
 
 POST a file to calculate its CRC32 checksum:
 

test/http_client.c

@@ -2,6 +2,7 @@
 /*
  * http_client.c -- A simple HTTP/QUIC client
  */
+
 #ifndef WIN32
 #include <arpa/inet.h>
 #include <netinet/in.h>
@@ -52,7 +53,6 @@ struct path_elem {
 struct http_client_ctx {
     TAILQ_HEAD(, lsquic_conn_ctx)
                                  conn_ctxs;
-    struct service_port         *sport;
     const char                  *hostname;
     const char                  *method;
     const char                  *payload;
@@ -158,6 +158,7 @@ struct lsquic_stream_ctx {
     struct lsquic_reader reader;
 };
 
+
 static lsquic_stream_ctx_t *
 http_client_on_new_stream (void *stream_if_ctx, lsquic_stream_t *stream)
 {
@@ -205,6 +206,9 @@ http_client_on_new_stream (void *stream_if_ctx, lsquic_stream_t *stream)
 static void
 send_headers (lsquic_stream_ctx_t *st_h)
 {
+    const char *hostname = st_h->client_ctx->hostname;
+    if (!hostname)
+        hostname = st_h->client_ctx->prog->prog_hostname;
     lsquic_http_header_t headers_arr[] = {
         {
             .name  = { .iov_base = ":method",       .iov_len = 7, },
@@ -222,8 +226,8 @@ send_headers (lsquic_stream_ctx_t *st_h)
         },
         {
             .name  = { ":authority",     10, },
-            .value = { .iov_base = (void *) st_h->client_ctx->hostname,
+            .value = { .iov_base = (void *) hostname,
-                       .iov_len = strlen(st_h->client_ctx->hostname), },
+                       .iov_len = strlen(hostname), },
         },
         /*
         {
@@ -311,7 +315,7 @@ http_client_on_read (lsquic_stream_t *stream, lsquic_stream_ctx_t *st_h)
     unsigned char buf[0x200];
     unsigned nreads = 0;
 #ifdef WIN32
-    srand(GetTickCount());
+	srand(GetTickCount());
 #endif
 
     do
@@ -407,7 +411,6 @@ usage (const char *prog)
 "Usage: %s [opts]\n"
 "\n"
 "Options:\n"
-"				-6 MUST be entered before -s in order to work."
 "   -p PATH     Path to request.  May be specified more than once.\n"
 "   -n CONNS    Number of concurrent connections.  Defaults to 1.\n"
 "   -r NREQS    Total number of requests to send.  Defaults to 1.\n"
@@ -420,8 +423,8 @@ usage (const char *prog)
 "                 content-length\n"
 "   -K          Discard server response\n"
 "   -I          Abort on incomplete reponse from server\n"
-"	-6 IPv6	    The client will try to connect via IPv6\n"
+"   -4          Prefer IPv4 when resolving hostname\n"
-"				  if this flag is used. If not it will use IPv4.\n"
+"   -6          Prefer IPv6 when resolving hostname\n"
             , prog);
 }
 
@@ -436,14 +439,11 @@ main (int argc, char **argv)
     struct sport_head sports;
     struct prog prog;
 
-    ipv6 = 0;
-
     TAILQ_INIT(&sports);
     memset(&client_ctx, 0, sizeof(client_ctx));
     client_ctx.hcc_concurrency = 1;
     TAILQ_INIT(&client_ctx.hcc_path_elems);
     TAILQ_INIT(&client_ctx.conn_ctxs);
-    client_ctx.hostname = "localhost";
     client_ctx.method = "GET";
     client_ctx.hcc_concurrency = 1;
     client_ctx.hcc_reqs_per_conn = 1;
@@ -456,11 +456,14 @@ main (int argc, char **argv)
 
     prog_init(&prog, LSENG_HTTP, &sports, &http_client_if, &client_ctx);
 
-    while (-1 != (opt = getopt(argc, argv, PROG_OPTS "6r:R:IKu:EP:M:n:H:p:h")))
+    while (-1 != (opt = getopt(argc, argv, PROG_OPTS "46r:R:IKu:EP:M:n:H:p:h")))
     {
         switch (opt) {
+        case '4':
+            prog.prog_ipver = 4;
+            break;
         case '6':
-            ipv6 = 1;
+            prog.prog_ipver = 4;
             break;
         case 'I':
             client_ctx.hcc_flags |= HCC_ABORT_ON_INCOMPLETE;
@@ -505,7 +508,7 @@ main (int argc, char **argv)
             break;
         case 'H':
             client_ctx.hostname = optarg;
-            prog.prog_hostname = optarg; /* Pokes into prog */
+            prog.prog_hostname = optarg;            /* Pokes into prog */
             break;
         case 'p':
             pe = calloc(1, sizeof(*pe));

test/prog.c

@@ -83,12 +83,15 @@ void
 prog_print_common_options (const struct prog *prog, FILE *out)
 {
     fprintf(out,
-"   -s SVCPORT  The port on which the client should connect.\n"
+"   -s SERVER   Server address.  Takes on the form of host:port, host,\n"
-"                 If no -s option is given, port 443\n"
+"                 or port.  If host is not an IPv4 or IPv6 address, it is\n"
-"                 is used.\n"
+"                 resolved.  If host is not set, the value of SNI is\n"
-"                 You can also specify an certain ipadress to be used here.\n"
+"                 use (see the -H flag).  If port is not set, the default\n"
-"                 To do that enter an ipadress and the port seperated by :\n"
+"                 is 443.  Examples:\n"
-"                 e.g -s ::1:12345 or -s 0.0.0.0:12345 or -s 443 or -s example.com:443\n"
+"                     127.0.0.1:12345\n"
+"                     ::1:12345\n"
+"                     example.com\n"
+"                     example.com:8443\n"
 #if LSQUIC_DONTFRAG_SUPPORTED
 "   -D          Set `do not fragment' flag on outgoing UDP packets\n"
 #endif
@@ -124,8 +127,9 @@ prog_print_common_options (const struct prog *prog, FILE *out)
     {
         if (prog->prog_engine_flags & LSENG_HTTP)
             fprintf(out,
-"   -H host     Value of `host' HTTP header.  Defaults to `localhost'.  This\n"
+"   -H host     Value of `host' HTTP header.  This is also used as SNI\n"
-"                 is also used as SNI.\n"
+"                 in Client Hello.  This option is used to override the\n"
+"                 `host' part of the address specified using -s flag.\n"
             );
         else
             fprintf(out,
@@ -176,7 +180,6 @@ prog_set_opt (struct prog *prog, int opt, const char *arg)
     case 'o':
         return set_engine_option(&prog->prog_settings,
                                             &prog->prog_version_cleared, arg);
-    
     case 's':
         if (0 == (prog->prog_engine_flags & LSENG_SERVER) &&
                                             !TAILQ_EMPTY(prog->prog_sports))
@@ -373,7 +376,9 @@ prog_prep (struct prog *prog)
 
     if (TAILQ_EMPTY(prog->prog_sports))
     {
-        s = prog_add_sport(prog, "443");
+        if (!prog->prog_hostname)
+            return -1;
+        s = prog_add_sport(prog, prog->prog_hostname);
         if (0 != s)
             return -1;
     }

test/prog.h

@@ -6,8 +6,6 @@
 #ifndef PROG_H
 #define PROG_H 1
 
-int ipv6;	/*True = Program uses ipv6, False = Program uses ipv4*/
-
 struct event;
 struct event_base;
 struct lsquic_hash;
@@ -29,6 +27,7 @@ struct prog
     struct sport_head              *prog_sports;
     struct lsquic_engine           *prog_engine;
     const char                     *prog_hostname;
+    int                             prog_ipver;     /* 0, 4, or 6 */
 };
 
 void

test/test_common.c

@@ -27,6 +27,8 @@
 #include <sys/stat.h>
 #include <sys/queue.h>
 #include <fcntl.h>
+#include <sys/types.h>
+#include <regex.h>
 
 #include <event2/event.h>
 
@@ -146,45 +148,6 @@ static void getExtensionPtrs()
 
 #endif
 
-int get_Ip_from_DNS(const char* hostname, struct service_port * sport, const char* port, int version)
-{
-    struct sockaddr_in  *const sa4 = (void *)&sport->sas;
-    struct sockaddr_in6 *const sa6 = (void *)&sport->sas;
-    struct addrinfo hints, *servinfo;
-    int rv;
-    char ip[INET6_ADDRSTRLEN];
-
-    memset(&hints, 0, sizeof(hints));
-    if (version)
-        hints.ai_family = AF_INET6;
-    else
-        hints.ai_family = AF_INET;
-    hints.ai_socktype = SOCK_STREAM;
-
-    if ((rv = getaddrinfo(hostname, port, &hints, &servinfo)) != 0){
-        LSQ_ERROR("getaddrinfo: %s\n", gai_strerror(rv));
-        freeaddrinfo(servinfo);
-        return 1;
-    }
-
-    if (version){ /*Ipv6*/
-        memset(sa6, 0, sizeof(*sa6));
-        sa6->sin6_addr = ((struct sockaddr_in6*) servinfo->ai_addr)->sin6_addr;
-        sa6->sin6_family = AF_INET6;
-        sa6->sin6_port = htons(atoi(port));
-        inet_ntop(AF_INET6, &sa6->sin6_addr, ip, INET6_ADDRSTRLEN);
-    }
-    else{/*Ipv4*/
-        sa4->sin_addr = ((struct sockaddr_in *) servinfo->ai_addr)->sin_addr;
-        sa4->sin_family = AF_INET;
-        sa4->sin_port = htons(atoi(port));
-        inet_ntop(AF_INET, &sa4->sin_addr, ip, INET6_ADDRSTRLEN);
-    }
-    memcpy(sport->host, ip, sizeof(ip));
-
-    freeaddrinfo(servinfo);
-    return 0;
-}
 
 static struct packets_in *
 allocate_packets_in (SOCKET_TYPE fd)
@@ -250,6 +213,13 @@ struct service_port *
 sport_new (const char *optarg, struct prog *prog)
 {
     struct service_port *const sport = malloc(sizeof(*sport));
+    regex_t re;
+    regmatch_t matches[5];
+    int re_code, port, e;
+    const char *host;
+    const char *port_str;
+    struct addrinfo hints, *res = NULL;
+    char errbuf[80];
 #if __linux__
     sport->n_dropped = 0;
     sport->drop_init = 0;
@@ -264,51 +234,109 @@ sport_new (const char *optarg, struct prog *prog)
     if (if_name)
     {
         strncpy(sport->if_name, if_name + 1, sizeof(sport->if_name) - 1);
-        sport->if_name[sizeof(sport->if_name) - 1] = '\0';
+        sport->if_name[ sizeof(sport->if_name) - 1 ] = '\0';
         *if_name = '\0';
     }
     else
         sport->if_name[0] = '\0';
 #endif
-
+    re_code = regcomp(&re, "^(.*):([0-9][0-9]*)$"
-    char *port = strrchr(addr, ':');
+                          "|^([0-9][0-9]*)$"
-    if (!port){/*IpAdress wasn't specified by the user*/
+                          "|^(..*)$"
-        if (get_Ip_from_DNS(prog->prog_hostname, sport, addr, ipv6) == 1)
+                                                    , REG_EXTENDED);
-            goto err;
+    if (re_code != 0)
+    {
+        regerror(re_code, &re, errbuf, sizeof(errbuf));
+        LSQ_ERROR("cannot compile regex: %s", errbuf);
+        goto err;
     }
-    else {
+    if (0 != regexec(&re, addr, sizeof(matches) / sizeof(matches[0]),
-        *port = '\0';
+                                                            matches, 0))
-        ++port;
+    {
-        
+        LSQ_ERROR("Invalid argument `%s'", addr);
-        struct sockaddr_in  *const sa4 = (void *)&sport->sas;
+        goto err;
-        struct sockaddr_in6 *const sa6 = (void *)&sport->sas;
-        
-        if (inet_pton(AF_INET, addr, &sa4->sin_addr)){
-            sa4->sin_family = AF_INET;
-            sa4->sin_port = htons(atoi(port));
-
-            if ((uintptr_t)port - (uintptr_t)addr > sizeof(sport->host))
-                goto err;
-            memcpy(sport->host, addr, port - addr);
-        }
-        else if (memset(sa6, 0, sizeof(*sa6)), inet_pton(AF_INET6, addr, &sa6->sin6_addr)){
-            sa6->sin6_family = AF_INET6;
-            sa6->sin6_port = htons(atoi(port));
-
-            if ((uintptr_t)port - (uintptr_t)addr > sizeof(sport->host))
-                goto err;
-            memcpy(sport->host, addr, port - addr);
-        }
-        else if (get_Ip_from_DNS(addr, sport, port, ipv6) != 0)
-            goto err;
     }
-    
+    if (matches[1].rm_so >= 0)
+    {
+        addr[ matches[1].rm_so + matches[1].rm_eo ] = '\0';
+        host = addr;
+        port_str = &addr[ matches[2].rm_so ];
+        port = atoi(port_str);
+    }
+    else if (matches[3].rm_so >= 0)
+    {
+        if (!prog->prog_hostname)
+        {
+            LSQ_ERROR("hostname is not specified");
+            goto err;
+        }
+        host = prog->prog_hostname;
+        port_str = &addr[ matches[3].rm_so ];
+        port = atoi(port_str);
+    }
+    else
+    {
+        assert(matches[4].rm_so >= 0);
+        host = addr;
+        port_str = "443";
+        port = 443;
+    }
+    assert(host);
+    LSQ_DEBUG("host: %s; port: %d", host, port);
+    if (strlen(host) > sizeof(sport->host) - 1)
+    {
+        LSQ_ERROR("argument `%s' too long", host);
+        goto err;
+    }
+    strcpy(sport->host, host);
+
+    struct sockaddr_in  *const sa4 = (void *) &sport->sas;
+    struct sockaddr_in6 *const sa6 = (void *) &sport->sas;
+    if        (inet_pton(AF_INET, host, &sa4->sin_addr)) {
+        sa4->sin_family = AF_INET;
+        sa4->sin_port   = htons(port);
+    } else if (memset(sa6, 0, sizeof(*sa6)),
+                    inet_pton(AF_INET6, host, &sa6->sin6_addr)) {
+        sa6->sin6_family = AF_INET6;
+        sa6->sin6_port   = htons(port);
+    } else
+    {
+        memset(&hints, 0, sizeof(hints));
+        hints.ai_flags = AI_NUMERICSERV;
+        if (prog->prog_ipver == 4)
+            hints.ai_family = AF_INET;
+        else if (prog->prog_ipver == 6)
+            hints.ai_family = AF_INET6;
+        e = getaddrinfo(host, port_str, &hints, &res);
+        if (e != 0)
+        {
+            LSQ_ERROR("could not resolve %s:%s: %s", host, port_str,
+                                                        gai_strerror(e));
+            goto err;
+        }
+        if (res->ai_addrlen > sizeof(sport->sas))
+        {
+            LSQ_ERROR("resolved socket length is too long");
+            goto err;
+        }
+        memcpy(&sport->sas, res->ai_addr, res->ai_addrlen);
+        if (!prog->prog_hostname)
+            prog->prog_hostname = sport->host;
+    }
+
+    if (0 == re_code)
+        regfree(&re);
+    if (res)
+        freeaddrinfo(res);
     free(addr);
     sport->sp_prog = prog;
     return sport;
 
-err:
+  err:
-    LSQ_ERROR("Couldn't resolve hostname or ip-address");
+    if (0 == re_code)
+        regfree(&re);
+    if (res)
+        freeaddrinfo(res);
     free(sport);
     free(addr);
     return NULL;
@@ -456,7 +484,7 @@ read_one_packet (struct read_iter *iter)
     if (SOCKET_ERROR == socket_ret) {
         if (WSAEWOULDBLOCK != WSAGetLastError())
             LSQ_ERROR("recvmsg: %d", WSAGetLastError());
-    return ROP_ERROR;
+	return ROP_ERROR;
     }
 #endif
 

test/test_common.h

@@ -106,13 +106,4 @@ create_lsquic_reader_ctx (const char *filename);
 void
 destroy_lsquic_reader_ctx (struct reader_ctx *ctx);
 
-/*Function resolves a Hostname into an Ip Adress
-Parameters:
--hostname	the URL of the website
--sport      the service port structure that stores the ip
--port       the port of the connection
--version	0 for ipv4 and 1 for ipv6
-*/
-int
-get_Ip_from_DNS(const char* hostname, struct service_port * sport, const char* port, int version);
 #endif