This will clean (disable buffer/trigger/channels) when doing
something like a CTRL-C. Otherwise restarting generic_buffer requires a
manual echo 0 > buffer/enable

This also cleanup up all the code freeing string buffers at
the end of main. We initialize all pointers to NULL so that cleanup can
all be done under a single error label.

Signed-off-by: Crestez Dan Leonard <leonard.cres...@intel.com>
---
 tools/iio/iio_generic_buffer.c | 172 ++++++++++++++++++++++++++---------------
 1 file changed, 108 insertions(+), 64 deletions(-)

diff --git a/tools/iio/iio_generic_buffer.c b/tools/iio/iio_generic_buffer.c
index 2429c78..972f400 100644
--- a/tools/iio/iio_generic_buffer.c
+++ b/tools/iio/iio_generic_buffer.c
@@ -32,6 +32,8 @@
 #include <endian.h>
 #include <getopt.h>
 #include <inttypes.h>
+#include <stdbool.h>
+#include <signal.h>
 #include "iio_utils.h"
 
 /**
@@ -254,6 +256,65 @@ void print_usage(void)
                "  -w <n>     Set delay between reads in us (event-less 
mode)\n");
 }
 
+enum autochan autochannels = AUTOCHANNELS_DISABLED;
+char *dev_dir_name = NULL;
+char *buf_dir_name = NULL;
+bool current_trigger_set = false;
+
+void cleanup(void)
+{
+       int ret;
+
+       /* Disable trigger */
+       if (dev_dir_name && current_trigger_set) {
+               /* Disconnect the trigger - just write a dummy name. */
+               ret = write_sysfs_string("trigger/current_trigger",
+                                        dev_dir_name, "NULL");
+               if (ret < 0)
+                       fprintf(stderr, "Failed to disable trigger: %s\n",
+                               strerror(-ret));
+               current_trigger_set = false;
+       }
+
+       /* Disable buffer */
+       if (buf_dir_name) {
+               ret = write_sysfs_int("enable", buf_dir_name, 0);
+               if (ret < 0)
+                       fprintf(stderr, "Failed to disable buffer: %s\n",
+                               strerror(-ret));
+       }
+
+       /* Disable channels if auto-enabled */
+       if (dev_dir_name && autochannels == AUTOCHANNELS_ACTIVE) {
+               ret = enable_disable_all_channels(dev_dir_name, 0);
+               if (ret)
+                       fprintf(stderr, "Failed to disable all channels\n");
+               autochannels = AUTOCHANNELS_DISABLED;
+       }
+}
+
+void sig_handler(int signum)
+{
+       fprintf(stderr, "Caught signal %d\n", signum);
+       cleanup();
+       exit(-signum);
+}
+
+void register_cleanup(void)
+{
+       struct sigaction sa = { .sa_handler = sig_handler };
+       const int signums[] = { SIGINT, SIGTERM, SIGABRT };
+       int ret, i;
+
+       for (i = 0; i < ARRAY_SIZE(signums); ++i) {
+               ret = sigaction(signums[i], &sa, NULL);
+               if (ret) {
+                       perror("Failed to register signal handler");
+                       exit(-1);
+               }
+       }
+}
+
 int main(int argc, char **argv)
 {
        unsigned long num_loops = 2;
@@ -261,25 +322,24 @@ int main(int argc, char **argv)
        unsigned long buf_len = 128;
 
        int ret, c, i, j, toread;
-       int fp;
+       int fp = -1;
 
-       int num_channels;
+       int num_channels = 0;
        char *trigger_name = NULL, *device_name = NULL;
-       char *dev_dir_name, *buf_dir_name;
 
-       int datardytrigger = 1;
-       char *data;
+       char *data = NULL;
        ssize_t read_size;
        int dev_num, trig_num;
-       char *buffer_access;
+       char *buffer_access = NULL;
        int scan_size;
        int noevents = 0;
        int notrigger = 0;
-       enum autochan autochannels = AUTOCHANNELS_DISABLED;
        char *dummy;
 
        struct iio_channel_info *channels;
 
+       register_cleanup();
+
        while ((c = getopt(argc, argv, "ac:egl:n:t:w:")) != -1) {
                switch (c) {
                case 'a':
@@ -288,8 +348,10 @@ int main(int argc, char **argv)
                case 'c':
                        errno = 0;
                        num_loops = strtoul(optarg, &dummy, 10);
-                       if (errno)
-                               return -errno;
+                       if (errno) {
+                               ret = -errno;
+                               goto error;
+                       }
 
                        break;
                case 'e':
@@ -301,26 +363,30 @@ int main(int argc, char **argv)
                case 'l':
                        errno = 0;
                        buf_len = strtoul(optarg, &dummy, 10);
-                       if (errno)
-                               return -errno;
+                       if (errno) {
+                               ret = -errno;
+                               goto error;
+                       }
 
                        break;
                case 'n':
                        device_name = optarg;
                        break;
                case 't':
-                       trigger_name = optarg;
-                       datardytrigger = 0;
+                       trigger_name = strdup(optarg);
                        break;
                case 'w':
                        errno = 0;
                        timedelay = strtoul(optarg, &dummy, 10);
-                       if (errno)
-                               return -errno;
+                       if (errno) {
+                               ret = -errno;
+                               goto error;
+                       }
                        break;
                case '?':
                        print_usage();
-                       return -1;
+                       ret = -1;
+                       goto error;
                }
        }
 
@@ -334,14 +400,17 @@ int main(int argc, char **argv)
        dev_num = find_type_by_name(device_name, "iio:device");
        if (dev_num < 0) {
                fprintf(stderr, "Failed to find the %s\n", device_name);
-               return dev_num;
+               ret = dev_num;
+               goto error;
        }
 
        printf("iio device number being used is %d\n", dev_num);
 
        ret = asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);
-       if (ret < 0)
-               return -ENOMEM;
+       if (ret < 0) {
+               ret = -ENOMEM;
+               goto error;
+       }
 
        if (!notrigger) {
                if (!trigger_name) {
@@ -354,7 +423,7 @@ int main(int argc, char **argv)
                                       "%s-dev%d", device_name, dev_num);
                        if (ret < 0) {
                                ret = -ENOMEM;
-                               goto error_free_dev_dir_name;
+                               goto error;
                        }
                }
 
@@ -367,7 +436,7 @@ int main(int argc, char **argv)
                                       "%s-trigger", device_name);
                        if (ret < 0) {
                                ret = -ENOMEM;
-                               goto error_free_dev_dir_name;
+                               goto error;
                        }
                }
 
@@ -376,7 +445,7 @@ int main(int argc, char **argv)
                        fprintf(stderr, "Failed to find the trigger %s\n",
                                trigger_name);
                        ret = trig_num;
-                       goto error_free_triggername;
+                       goto error;
                }
 
                printf("iio trigger number being used is %d\n", trig_num);
@@ -392,7 +461,7 @@ int main(int argc, char **argv)
        if (ret) {
                fprintf(stderr, "Problem reading scan element information\n"
                        "diag %s\n", dev_dir_name);
-               goto error_free_triggername;
+               goto error;
        }
        if (num_channels && autochannels == AUTOCHANNELS_ENABLED) {
                fprintf(stderr, "Auto-channels selected but some channels "
@@ -407,7 +476,7 @@ int main(int argc, char **argv)
                ret = enable_disable_all_channels(dev_dir_name, 1);
                if (ret) {
                        fprintf(stderr, "Failed to enable all channels\n");
-                       goto error_free_triggername;
+                       goto error;
                }
 
                /* This flags that we need to disable the channels again */
@@ -419,12 +488,12 @@ int main(int argc, char **argv)
                        fprintf(stderr, "Problem reading scan element "
                                "information\n"
                                "diag %s\n", dev_dir_name);
-                       goto error_disable_channels;
+                       goto error;
                }
                if (!num_channels) {
                        fprintf(stderr, "Still no channels after "
                                "auto-enabling, giving up\n");
-                       goto error_disable_channels;
+                       goto error;
                }
        }
 
@@ -436,7 +505,7 @@ int main(int argc, char **argv)
                        "/*_en or pass -a to autoenable channels and "
                        "try again.\n", dev_dir_name);
                ret = -ENOENT;
-               goto error_free_triggername;
+               goto error;
        }
 
        /*
@@ -448,7 +517,7 @@ int main(int argc, char **argv)
                       "%siio:device%d/buffer", iio_dir, dev_num);
        if (ret < 0) {
                ret = -ENOMEM;
-               goto error_free_channels;
+               goto error;
        }
 
        if (!notrigger) {
@@ -463,34 +532,34 @@ int main(int argc, char **argv)
                if (ret < 0) {
                        fprintf(stderr,
                                "Failed to write current_trigger file\n");
-                       goto error_free_buf_dir_name;
+                       goto error;
                }
        }
 
        /* Setup ring buffer parameters */
        ret = write_sysfs_int("length", buf_dir_name, buf_len);
        if (ret < 0)
-               goto error_free_buf_dir_name;
+               goto error;
 
        /* Enable the buffer */
        ret = write_sysfs_int("enable", buf_dir_name, 1);
        if (ret < 0) {
                fprintf(stderr,
                        "Failed to enable buffer: %s\n", strerror(-ret));
-               goto error_free_buf_dir_name;
+               goto error;
        }
 
        scan_size = size_from_channelarray(channels, num_channels);
        data = malloc(scan_size * buf_len);
        if (!data) {
                ret = -ENOMEM;
-               goto error_free_buf_dir_name;
+               goto error;
        }
 
        ret = asprintf(&buffer_access, "/dev/iio:device%d", dev_num);
        if (ret < 0) {
                ret = -ENOMEM;
-               goto error_free_data;
+               goto error;
        }
 
        /* Attempt to open non blocking the access dev */
@@ -498,7 +567,7 @@ int main(int argc, char **argv)
        if (fp == -1) { /* TODO: If it isn't there make the node */
                ret = -errno;
                fprintf(stderr, "Failed to open %s\n", buffer_access);
-               goto error_free_buffer_access;
+               goto error;
        }
 
        for (j = 0; j < num_loops; j++) {
@@ -511,7 +580,7 @@ int main(int argc, char **argv)
                        ret = poll(&pfd, 1, -1);
                        if (ret < 0) {
                                ret = -errno;
-                               goto error_close_buffer_access;
+                               goto error;
                        } else if (ret == 0) {
                                continue;
                        }
@@ -536,45 +605,20 @@ int main(int argc, char **argv)
                                     num_channels);
        }
 
-       /* Stop the buffer */
-       ret = write_sysfs_int("enable", buf_dir_name, 0);
-       if (ret < 0)
-               goto error_close_buffer_access;
-
-       if (!notrigger)
-               /* Disconnect the trigger - just write a dummy name. */
-               ret = write_sysfs_string("trigger/current_trigger",
-                                        dev_dir_name, "NULL");
-               if (ret < 0)
-                       fprintf(stderr, "Failed to write to %s\n",
-                               dev_dir_name);
+error:
+       cleanup();
 
-error_close_buffer_access:
-       if (close(fp) == -1)
+       if (fp >= 0 && close(fp) == -1)
                perror("Failed to close buffer");
-
-error_free_buffer_access:
        free(buffer_access);
-error_free_data:
        free(data);
-error_free_buf_dir_name:
        free(buf_dir_name);
-error_free_channels:
        for (i = num_channels - 1; i >= 0; i--) {
                free(channels[i].name);
                free(channels[i].generic_name);
        }
        free(channels);
-error_free_triggername:
-       if (datardytrigger)
-               free(trigger_name);
-error_disable_channels:
-       if (autochannels == AUTOCHANNELS_ACTIVE) {
-               ret = enable_disable_all_channels(dev_dir_name, 0);
-               if (ret)
-                       fprintf(stderr, "Failed to disable all channels\n");
-       }
-error_free_dev_dir_name:
+       free(trigger_name);
        free(dev_dir_name);
 
        return ret;
-- 
2.5.5

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