resolved: fix error handling in resolved-dns-stream

During the transition from system functions using errno to our own read and write functions with negative return codes some errors where introduced. This patch correctly convert errno to negative return codes for read and write and fix checks still using errno instead of the return code.

Closes #9283

diff --git a/src/resolve/resolved-dns-stream.c b/src/resolve/resolved-dns-stream.c
index 4ab15ebcaaf851daa84406d926fe421ca3e404e7..d133efa751e43d0e9267b06a743a3d191ef0dcd3 100644 (file)
--- a/src/resolve/resolved-dns-stream.c
+++ b/src/resolve/resolved-dns-stream.c
@@ -245,8 +245,11 @@ static ssize_t dns_stream_writev(DnsStream *s, const struct iovec *iov, size_t i
                                 r = -EAGAIN;
                 } else
                         s->tfo_salen = 0; /* connection is made */
-        } else
+        } else {
                 r = writev(s->fd, iov, iovcnt);
+                if (r < 0)
+                        r = -errno;
+        }
 
         return r;
 }
@@ -278,7 +281,11 @@ static ssize_t dns_stream_read(DnsStream *s, void *buf, size_t count) {
                 }
         } else
 #endif
+        {
                 ss = read(s->fd, buf, count);
+                if (ss < 0)
+                        ss = -errno;
+        }
 
         return ss;
 }
@@ -370,8 +377,8 @@ static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *use
 
                 ss = dns_stream_writev(s, iov, 2, 0);
                 if (ss < 0) {
-                        if (!IN_SET(errno, EINTR, EAGAIN))
-                                return dns_stream_complete(s, errno);
+                        if (!IN_SET(-ss, EINTR, EAGAIN))
+                                return dns_stream_complete(s, -ss);
                 } else
                         s->n_written += ss;
 
@@ -392,8 +399,8 @@ static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *use
 
                         ss = dns_stream_read(s, (uint8_t*) &s->read_size + s->n_read, sizeof(s->read_size) - s->n_read);
                         if (ss < 0) {
-                                if (!IN_SET(errno, EINTR, EAGAIN))
-                                        return dns_stream_complete(s, errno);
+                                if (!IN_SET(-ss, EINTR, EAGAIN))
+                                        return dns_stream_complete(s, -ss);
                         } else if (ss == 0)
                                 return dns_stream_complete(s, ECONNRESET);
                         else