[PATCH v7 7/7] dumpcap: improve pcapng error reporting

[Stephen Hemminger]

Print meaningful error messages when rte_pcapng_add_interface()
or rte_pcapng_write_stats() fails instead of silently ignoring
the error or printing a generic message.

Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
---
 app/dumpcap/main.c | 36 ++++++++++++++++++++++--------------
 1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/app/dumpcap/main.c b/app/dumpcap/main.c
index 46a6cb251e..f105ee92c2 100644
--- a/app/dumpcap/main.c
+++ b/app/dumpcap/main.c
@@ -587,9 +587,16 @@ report_packet_stats(dumpcap_out_t out)
                ifrecv = pdump_stats.accepted + pdump_stats.filtered;
                ifdrop = pdump_stats.nombuf + pdump_stats.ringfull;
 
-               if (use_pcapng)
-                       rte_pcapng_write_stats(out.pcapng, intf->port,
-                                              ifrecv, ifdrop, NULL);
+               if (use_pcapng) {
+                       ssize_t written;
+
+                       written = rte_pcapng_write_stats(out.pcapng, intf->port,
+                                                        ifrecv, ifdrop, NULL);
+                       if (written < 0) {
+                               fprintf(stderr, "Failed to write stats for %s: 
%s\n",
+                                       intf->name, rte_strerror(-written));
+                       }
+               }
 
                if (ifrecv == 0)
                        percent = 0;
@@ -760,7 +767,7 @@ static char *get_os_info(void)
 
 static dumpcap_out_t create_output(void)
 {
-       dumpcap_out_t ret;
+       dumpcap_out_t out;
        static char tmp_path[PATH_MAX];
        int fd;
 
@@ -802,19 +809,20 @@ static dumpcap_out_t create_output(void)
                struct interface *intf;
                char *os = get_os_info();
 
-               ret.pcapng = rte_pcapng_fdopen(fd, os, NULL,
+               out.pcapng = rte_pcapng_fdopen(fd, os, NULL,
                                           version(), capture_comment);
-               if (ret.pcapng == NULL)
+               if (out.pcapng == NULL)
                        rte_exit(EXIT_FAILURE, "pcapng_fdopen failed: %s\n",
                                 strerror(rte_errno));
                free(os);
 
                TAILQ_FOREACH(intf, &interfaces, next) {
-                       if (rte_pcapng_add_interface(ret.pcapng, intf->port, 
DLT_EN10MB,
-                                                    intf->ifname, 
intf->ifdescr,
-                                                    intf->opts.filter) < 0)
-                               rte_exit(EXIT_FAILURE, 
"rte_pcapng_add_interface %u failed\n",
-                                       intf->port);
+                       int ret = rte_pcapng_add_interface(out.pcapng, 
intf->port, DLT_EN10MB,
+                                                      intf->ifname, 
intf->ifdescr,
+                                                      intf->opts.filter);
+                       if (ret < 0)
+                               rte_exit(EXIT_FAILURE, 
"rte_pcapng_add_interface %u failed: %s\n",
+                                        intf->port, rte_strerror(-ret));
                }
        } else {
                pcap_t *pcap;
@@ -825,13 +833,13 @@ static dumpcap_out_t create_output(void)
                if (pcap == NULL)
                        rte_exit(EXIT_FAILURE, "pcap_open_dead failed\n");
 
-               ret.dumper = pcap_dump_fopen(pcap, fdopen(fd, "w"));
-               if (ret.dumper == NULL)
+               out.dumper = pcap_dump_fopen(pcap, fdopen(fd, "w"));
+               if (out.dumper == NULL)
                        rte_exit(EXIT_FAILURE, "pcap_dump_fopen failed: %s\n",
                                 pcap_geterr(pcap));
        }
 
-       return ret;
+       return out;
 }
 
 static void enable_pdump(struct rte_ring *r, struct rte_mempool *mp)
-- 
2.51.0