cgmnlm

commit 9b1a618b4211a029c352c72f6d273e3085c8457d
parent abcb9caf86020a7cdd9f502fe01eb5db3c70c685
Author: Drew DeVault <sir@cmpwn.com>
Date:   Sun, 20 Sep 2020 13:30:28 -0400

Implement reading response body & meta

Diffstat:
M
include/client.h
 | 
4
++++
M
src/client.c
 | 
42
++++++++++++++++++++++++++++++++++++++++++
M
src/gmnic.c
 | 
80
+++++++++++++++++++++++++++++++++++++++++++++++++------------------------------

3 files changed, 96 insertions(+), 30 deletions(-)
diff --git a/include/client.h b/include/client.h
@@ -46,6 +46,7 @@ enum gemini_result {
 	// use SSL_get_error(resp->ssl, resp->status) to get details
 	GEMINI_ERR_SSL,
 	GEMINI_ERR_IO,
+	GEMINI_ERR_PROTOCOL,
 };
 
 // Requests the specified URL via the gemini protocol. If options is non-NULL,
@@ -64,4 +65,7 @@ enum gemini_result gemini_request(const char *url,
 // gemini_response_finish.
 void gemini_response_finish(struct gemini_response *resp);
 
+// Returns a user-friendly string describing an error.
+const char *gemini_strerr(enum gemini_result r, struct gemini_response *resp);
+
 #endif
diff --git a/src/client.c b/src/client.c
@@ -2,6 +2,7 @@
 #include <errno.h>
 #include <netdb.h>
 #include <openssl/bio.h>
+#include <openssl/err.h>
 #include <openssl/ssl.h>
 #include <stdlib.h>
 #include <string.h>
@@ -168,6 +169,21 @@ gemini_request(const char *url, struct gemini_options *options,
 		goto cleanup;
 	}
 
+	if (r < 3 || strcmp(&buf[r - 2], "\r\n") != 0) {
+		res = GEMINI_ERR_PROTOCOL;
+		goto cleanup;
+	}
+
+	char *endptr;
+	resp->status = (int)strtol(buf, &endptr, 10);
+	if (*endptr != ' ' || resp->status <= 10 || resp->status >= 70) {
+		res = GEMINI_ERR_PROTOCOL;
+		goto cleanup;
+	}
+	resp->meta = calloc(r - 5 /* 2 digits, space, and CRLF */ + 1 /* NUL */, 1);
+	strncpy(resp->meta, &endptr[1], r - 5);
+	resp->meta[r - 5] = '\0';
+
 cleanup:
 	curl_url_cleanup(uri);
 	return res;
@@ -188,3 +204,29 @@ gemini_response_finish(struct gemini_response *resp)
 	SSL_CTX_free(resp->ssl_ctx);
 	free(resp->meta);
 }
+
+const char *
+gemini_strerr(enum gemini_result r, struct gemini_response *resp)
+{
+	switch (r) {
+	case GEMINI_OK:
+		return "OK";
+	case GEMINI_ERR_OOM:
+		return "Out of memory";
+	case GEMINI_ERR_INVALID_URL:
+		return "Invalid URL";
+	case GEMINI_ERR_RESOLVE:
+		return gai_strerror(resp->status);
+	case GEMINI_ERR_CONNECT:
+		return strerror(errno);
+	case GEMINI_ERR_SSL:
+		return ERR_error_string(
+			SSL_get_error(resp->ssl, resp->status),
+			NULL);
+	case GEMINI_ERR_IO:
+		return "I/O error";
+	case GEMINI_ERR_PROTOCOL:
+		return "Protocol error";
+	}
+	assert(0);
+}
diff --git a/src/gmnic.c b/src/gmnic.c
@@ -1,9 +1,13 @@
 #include <assert.h>
+#include <errno.h>
 #include <getopt.h>
+#include <openssl/bio.h>
 #include <openssl/err.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
 #include "client.h"
 
 static void
@@ -17,11 +21,15 @@ usage(char *argv_0)
 int
 main(int argc, char *argv[])
 {
-	bool headers = false, follow_redirect = false;
-	char *certificate = NULL, *input = NULL;
+	enum header_mode {
+		OMIT_HEADERS,
+		SHOW_HEADERS,
+		ONLY_HEADERS,
+	};
+	enum header_mode headers = OMIT_HEADERS;
 
 	int c;
-	while ((c = getopt(argc, argv, "46C:d:hLI")) != -1) {
+	while ((c = getopt(argc, argv, "46C:d:hLiI")) != -1) {
 		switch (c) {
 		case '4':
 			assert(0); // TODO
@@ -30,25 +38,29 @@ main(int argc, char *argv[])
 			assert(0); // TODO
 			break;
 		case 'C':
-			certificate = optarg;
+			assert(0); // TODO: Client certificates
 			break;
 		case 'd':
-			input = optarg;
+			assert(0); // TODO: Input
 			break;
 		case 'h':
 			usage(argv[0]);
 			return 0;
 		case 'L':
-			follow_redirect = true;
+			assert(0); // TODO: Follow redirects
+			break;
+		case 'i':
+			headers = SHOW_HEADERS;
 			break;
 		case 'I':
-			headers = true;
+			headers = ONLY_HEADERS;
 			break;
 		default:
 			fprintf(stderr, "fatal: unknown flag %c", c);
 			return 1;
 		}
 	}
+
 	if (optind != argc - 1) {
 		usage(argv[0]);
 		return 1;
@@ -59,33 +71,41 @@ main(int argc, char *argv[])
 
 	struct gemini_response resp;
 	enum gemini_result r = gemini_request(argv[optind], NULL, &resp);
-	switch (r) {
-	case GEMINI_OK:
-		printf("OK\n");
-		break;
-	case GEMINI_ERR_OOM:
-		printf("OOM\n");
-		break;
-	case GEMINI_ERR_INVALID_URL:
-		printf("INVALID_URL\n");
-		break;
-	case GEMINI_ERR_RESOLVE:
-		printf("RESOLVE\n");
-		break;
-	case GEMINI_ERR_CONNECT:
-		printf("CONNECT\n");
+	if (r != GEMINI_OK) {
+		fprintf(stderr, "Error: %s\n", gemini_strerr(r, &resp));
+		gemini_response_finish(&resp);
+		return (int)r;
+	}
+
+	switch (headers) {
+	case ONLY_HEADERS:
+		printf("%d %s\n", resp.status, resp.meta);
 		break;
-	case GEMINI_ERR_SSL:
-		fprintf(stderr, "SSL error: %s\n", ERR_error_string(
-			SSL_get_error(resp.ssl, resp.status), NULL));
+	case SHOW_HEADERS:
+		printf("%d %s\n", resp.status, resp.meta);
+		/* fallthrough */
+	case OMIT_HEADERS:
+		for (int n = 1; n > 0;) {
+			char buf[BUFSIZ];
+			n = BIO_read(resp.bio, buf, BUFSIZ);
+			if (n == -1) {
+				fprintf(stderr, "Error: read\n");
+				return 1;
+			}
+			ssize_t w = 0;
+			while (w < (ssize_t)n) {
+				ssize_t x = write(STDOUT_FILENO, &buf[w], n - w);
+				if (x == -1) {
+					fprintf(stderr, "Error: write: %s\n",
+						strerror(errno));
+					return 1;
+				}
+				w += x;
+			}
+		}
 		break;
 	}
 
 	gemini_response_finish(&resp);
-
-	(void)headers;
-	(void)follow_redirect;
-	(void)certificate;
-	(void)input;
 	return 0;
 }