GopherProxy

	https.c - frontends - front-ends for some sites (experiment)
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	---
	https.c (4485B)
	---
	1 #include <sys/socket.h>
	2 #include <sys/types.h>
	3
	4 #include <ctype.h>
	5 #include <errno.h>
	6 #include <netdb.h>
	7 #include <stdarg.h>
	8 #include <stdint.h>
	9 #include <stdio.h>
	10 #include <stdlib.h>
	11 #include <string.h>
	12 #include <time.h>
	13 #include <unistd.h>
	14
	15 #include <tls.h>
	16
	17 #define READ_BUF_SIZ 16384 /* read buffer in bytes */
	18 #define MAX_RESPONSETIMEOUT 10 /* timeout in seconds */
	19 #define MAX_RESPONSESIZ 4194304 /* max download size in bytes */
	20
	21 static void
	22 die(const char *fmt, ...)
	23 {
	24 va_list ap;
	25
	26 va_start(ap, fmt);
	27 vfprintf(stderr, fmt, ap);
	28 va_end(ap);
	29
	30 exit(1);
	31 }
	32
	33 /* TODO: use die or rename die to fatal */
	34 void
	35 fatal(const char *s)
	36 {
	37 fputs(s, stderr);
	38 exit(1);
	39 }
	40
	41 char *
	42 readtls(struct tls *t)
	43 {
	44 char *buf;
	45 size_t len = 0, size = 0;
	46 ssize_t r;
	47
	48 /* always allocate an empty buffer */
	49 if (!(buf = calloc(1, size + 1)))
	50 die("calloc: %s\n", strerror(errno));
	51
	52 while (1) {
	53 if (len + READ_BUF_SIZ + 1 > size) {
	54 /* allocate size: common case is small textfiles…
	55 size += READ_BUF_SIZ;
	56 if (!(buf = realloc(buf, size + 1)))
	57 die("realloc: %s\n", strerror(errno));
	58 }
	59 r = tls_read(t, &buf[len], READ_BUF_SIZ);
	60 if (r == TLS_WANT_POLLIN \|\| r == TLS_WANT_POLLOUT) {
	61 continue;
	62 } else if (r <= 0) {
	63 break;
	64 }
	65 len += r;
	66 buf[len] = '\0';
	67 if (len > MAX_RESPONSESIZ)
	68 die("response is too big: > %zu bytes\n", MAX_RE…
	69 }
	70 if (r == -1)
	71 die("tls_read: %s\n", tls_error(t));
	72
	73 return buf;
	74 }
	75
	76 int
	77 edial(const char host, const char port)
	78 {
	79 struct addrinfo hints, res, res0;
	80 int error, save_errno, s;
	81 const char *cause = NULL;
	82 struct timeval timeout;
	83
	84 memset(&hints, 0, sizeof(hints));
	85 hints.ai_family = AF_UNSPEC;
	86 hints.ai_socktype = SOCK_STREAM;
	87 hints.ai_flags = AI_NUMERICSERV; /* numeric port only */
	88 if ((error = getaddrinfo(host, port, &hints, &res0)))
	89 die("%s: %s: %s:%s\n", __func__, gai_strerror(error), ho…
	90 s = -1;
	91 for (res = res0; res; res = res->ai_next) {
	92 s = socket(res->ai_family, res->ai_socktype,
	93 res->ai_protocol);
	94 if (s == -1) {
	95 cause = "socket";
	96 continue;
	97 }
	98
	99 timeout.tv_sec = MAX_RESPONSETIMEOUT;
	100 timeout.tv_usec = 0;
	101 if (setsockopt(s, SOL_SOCKET, SO_SNDTIMEO, &timeout, siz…
	102 die("%s: setsockopt: %s\n", __func__, strerror(e…
	103
	104 timeout.tv_sec = MAX_RESPONSETIMEOUT;
	105 timeout.tv_usec = 0;
	106 if (setsockopt(s, SOL_SOCKET, SO_RCVTIMEO, &timeout, siz…
	107 die("%s: setsockopt: %s\n", __func__, strerror(e…
	108
	109 if (connect(s, res->ai_addr, res->ai_addrlen) == -1) {
	110 cause = "connect";
	111 save_errno = errno;
	112 close(s);
	113 errno = save_errno;
	114 s = -1;
	115 continue;
	116 }
	117 break;
	118 }
	119 if (s == -1)
	120 die("%s: %s: %s:%s\n", __func__, cause, host, port);
	121 freeaddrinfo(res0);
	122
	123 return s;
	124 }
	125
	126 char *
	127 request(const char host, const char path, const char *headers)
	128 {
	129 struct tls *t;
	130 char request[4096];
	131 char *data;
	132 size_t len;
	133 ssize_t w;
	134 int fd;
	135
	136 /* use HTTP/1.0, don't use HTTP/1.1 using ugly chunked-encoding …
	137 snprintf(request, sizeof(request),
	138 "GET %s HTTP/1.0\r\n"
	139 "Host: %s\r\n"
	140 "Accept-Language: en-US,en;q=0.5\r\n"
	141 "Connection: close\r\n"
	142 "%s"
	143 "\r\n", path, host, headers);
	144
	145 if (tls_init() == -1)
	146 die("tls_init\n");
	147
	148 if (!(t = tls_client()))
	149 die("tls_client: %s\n", tls_error(t));
	150
	151 fd = edial(host, "443");
	152
	153 if (tls_connect_socket(t, fd, host) == -1)
	154 die("tls_connect: %s\n", tls_error(t));
	155
	156 data = request;
	157 len = strlen(data);
	158 while (len > 0) {
	159 w = tls_write(t, data, len);
	160 if (w == TLS_WANT_POLLIN \|\| w == TLS_WANT_POLLOUT)
	161 continue;
	162 else if (w == -1)
	163 die("tls_write: %s\n", tls_error(t));
	164 data += w;
	165 len -= w;
	166 }
	167
	168 data = readtls(t);
	169
	170 tls_close(t);
	171 tls_free(t);
	172
	173 return data;
	174 }
	175
	176 /* DEBUG */
	177 char *
	178 readfile(const char *file)
	179 {
	180 FILE *fp;
	181 char *buf;
	182 size_t n, len = 0, size = 0;
	183
	184 fp = fopen(file, "rb");
	185 if (!fp)
	186 die("fopen");
	187 buf = calloc(1, size + 1); /* always allocate an empty buffer */
	188 if (!buf)
	189 die("calloc");
	190 while (!feof(fp)) {
	191 if (len + READ_BUF_SIZ + 1 > size) {
	192 /* allocate size: common case is small textfiles…
	193 size += READ_BUF_SIZ;
	194 if (!(buf = realloc(buf, size + 1))) {
	195 fprintf(stderr, "realloc: %s\n", strerro…
	196 exit(1);
	197 }
	198 }
	199 if (!(n = fread(&buf[len], 1, READ_BUF_SIZ, fp)))
	200 break;
	201 len += n;
	202 buf[len] = '\0';
	203 if (n != READ_BUF_SIZ)
	204 break;
	205 }
	206 if (ferror(fp)) {
	207 fprintf(stderr, "fread: file: %s: %s\n", file, strerror(…
	208 exit(1);
	209 }
	210 fclose(fp);
	211
	212 return buf;
	213 }