nkiss

commit 94f5d599d18442fe4f4339e93b38a0bdd83ac87e
parent 7470481c1eff46db13b807c8da0d13aed08c2b1d
Author: Nihal Jere <nihal@nihaljere.xyz>
Date:   Thu, 18 Feb 2021 12:00:21 -0600

http.c: add redirection support

Diffstat:
M
http.c
 | 
110
++++++++++++++++++++++++++++++++++++++++++++++++++++---------------------------

1 file changed, 73 insertions(+), 37 deletions(-)
diff --git a/http.c b/http.c
@@ -16,6 +16,7 @@
 #include "util.h"
 
 #define READ_BUF_SIZ    16384
+#define MAX_REDIRECTIONS    5
 
 #ifndef TLS_CA_CERT_FILE
 #define TLS_CA_CERT_FILE "/etc/ssl/cert.pem"
@@ -161,7 +162,7 @@ https_request(void)
     const char *errstr;
     size_t n, len;
     ssize_t r;
-    int status = 0, ret = 1, stdport;
+    int status = 0, stdport;
 
     if (!(t = tls_client())) {
         fprintf(stderr, "tls_client: %s\n", tls_error(t));
@@ -220,9 +221,19 @@ https_request(void)
     }
     buf[len] = '\0';
 
-    if (!strncmp(buf, "HTTP/1.0 200 ", sizeof("HTTP/1.0 200 ") - 1) ||
-        !strncmp(buf, "HTTP/1.1 200 ", sizeof("HTTP/1.1 200 ") - 1))
-        status = 1;
+    if (!strncmp(buf, "HTTP/1.0 ", sizeof("HTTP/1.0 ") - 1) ||
+        !strncmp(buf, "HTTP/1.1 ", sizeof("HTTP/1.1 ") - 1)) {
+        p = buf + sizeof("HTTP/1.1 ") - 1;
+        /* OK, we can read response */
+        if (!strncmp(p, "200 ", sizeof("200 ") - 1)) {
+            status = 2;
+        /* redirection */
+        } else if (!strncmp(p, "302 ", sizeof("302 ") - 1) ||
+                 !strncmp(p, "303 ", sizeof("303 ") - 1) ||
+                 !strncmp(p, "307 ", sizeof("307 ") - 1)) {
+            status = 3;
+        }
+    }
 
     if (!(p = strstr(buf, "\r\n\r\n"))) {
         fprintf(stderr, "no HTTP header found or header too big\n");
@@ -231,13 +242,28 @@ https_request(void)
     *p = '\0'; /* NUL terminate header part */
     p += strlen("\r\n\r\n");
 
-    if (status) {
+    if (status == 2) {
         n = len - (p - buf);
         r = fwrite(p, 1, n, dest);
         if (ferror(dest)) {
             fprintf(stderr, "fwrite: %s\n", strerror(errno));
             goto err;
         }
+    } else if (status == 3) {
+        p = strstr(buf, "\r\nLocation: ");
+        if (p == NULL) {
+            fprintf(stderr, "http: no Location given for 3xx response\n");
+            goto err;
+        }
+        p += sizeof("\r\nLocation: ") - 1;
+
+        p = memccpy(url, p, '\r', 2048);
+        if (p == NULL) {
+            fprintf(stderr, "http: Location url too long\n");
+            goto err;
+        }
+        
+        *(p-1) = '\0';
     } else {
         /* if not 200 OK print header */
         fputs(buf, stderr);
@@ -258,7 +284,7 @@ https_request(void)
         }
         len += r;
 
-        if (status) {
+        if (status == 2) {
             r = fwrite(buf, 1, r, dest);
             if (ferror(dest)) {
                 fprintf(stderr, "fwrite: %s\n", strerror(errno));
@@ -267,7 +293,6 @@ https_request(void)
         }
 
     }
-    ret = 0;
 
 err:
     if (t) {
@@ -275,7 +300,7 @@ err:
         tls_free(t);
     }
 
-    return status ? ret : 2;
+    return status;
 }
 
 static int
@@ -284,7 +309,7 @@ http_request(void)
     char buf[READ_BUF_SIZ], *p;
     size_t n, len;
     ssize_t r;
-    int fd = -1, status = 0, ret = 1, stdport;
+    int fd = -1, status = 0, stdport;
 
     fd = edial(u.host, u.port);
 
@@ -357,6 +382,15 @@ http_request(void)
             fprintf(stderr, "http: no Location given for 3xx response\n");
             goto err;
         }
+        p += sizeof("\r\nLocation: ") - 1;
+
+        p = memccpy(url, p, '\r', 2048);
+        if (p == NULL) {
+            fprintf(stderr, "http: Location url too long\n");
+            goto err;
+        }
+        
+        *(p-1) = '\0';
     } else {
         /* if not 200 OK print header */
         fputs(buf, stderr);
@@ -383,56 +417,58 @@ http_request(void)
         }
 
     }
-    ret = 0;
 
 err:
     if (fd != -1)
         close(fd);
-    return status ? ret : 2;
+
+    return status;
 }
 
 int
 http_fetch(char *loc, char *path)
 {
-    int statuscode;
+    int statuscode = 3, redirs = 0;
 
     if (strlen(loc) > 2047)
         die("%s: url too long: %s", __func__, url);
 
     strcpy(url, loc);
 
-    if (parseuri(url, &u) == -1)
-        die("invalid url: %s", url);
-
-    if (config_timeout > 0) {
-        signal(SIGALRM, sighandler);
-    }
-
     mkdirs(dirname(path));
 
     if ((dest = fopen(path, "w")) == NULL) {
         die("%s: failed to open %s:", __func__, path);
     }
 
-    if (!strcmp(u.proto, "https")) {
-        if (tls_init())
-            die("tls_init failed");
-        if (!(tls_config = tls_config_new()))
-            die("tls config failed");
-        if (!u.port[0] && !strcmp(u.proto, "https"))
-            memcpy(u.port, "443", 4);
-        statuscode = https_request();
-    } else if (!strcmp(u.proto, "http")) {
-        if (!u.port[0])
-            memcpy(u.port, "80", 3);
-        statuscode = http_request();
-    } else {
-        if (u.proto[0])
-            die("unsupported protocol specified: %s", u.proto);
-        else
-            die("no protocol specified");
-    }
+    while (statuscode == 3 && redirs < MAX_REDIRECTIONS) {
+        if (parseuri(url, &u) == -1)
+            die("invalid url: %s", url);
 
+        if (config_timeout > 0) {
+            signal(SIGALRM, sighandler);
+        }
+
+        if (!strcmp(u.proto, "https")) {
+            if (tls_init())
+                die("tls_init failed");
+            if (!(tls_config = tls_config_new()))
+                die("tls config failed");
+            if (!u.port[0] && !strcmp(u.proto, "https"))
+                memcpy(u.port, "443", 4);
+            statuscode = https_request();
+        } else if (!strcmp(u.proto, "http")) {
+            if (!u.port[0])
+                memcpy(u.port, "80", 3);
+            statuscode = http_request();
+        } else {
+            if (u.proto[0])
+                die("unsupported protocol specified: %s", u.proto);
+            else
+                die("no protocol specified");
+        }
+
+    }
     fclose(dest);
 
     return statuscode;