osc/curl.c

#include <stdlib.h>
#include <string.h>
#include <curl/curl.h>

#include "utils.h"
#include "curl.h"
#include "keystone.h"

void init_string(struct string *s) {
    s->len = 0;
    s->ptr = malloc(s->len+1);
    if (s->ptr == NULL) {
        fprintf(stderr, "malloc() failed\n");
        exit(EXIT_FAILURE);
    }
    memset(s->ptr, 0, s->len+1);
}

size_t gobble(void *ptr, size_t size, size_t nmemb, void *s_) {
    return size*nmemb;
}

size_t string_stuffer(void *ptr, size_t size, size_t nmemb, void *s_) {
    struct string *s = s_;
    size_t new_len = s->len + size*nmemb;
    s->ptr = realloc(s->ptr, new_len+1);
    if (s->ptr == NULL) {
        fprintf(stderr, "realloc() failed\n");
        exit(EXIT_FAILURE);
    }
    memcpy(s->ptr+s->len, ptr, size*nmemb);
    s->ptr[new_len] = '\0';
    s->len = new_len;

    return size*nmemb;
}

int submit_api_request(struct string *s, const char *endpoint, const char *path) {
    char url[MAX_BUF_SZ] = { 0 };
    api_url_build(url, endpoint, path);

    CURLcode err = curl_global_init(CURL_GLOBAL_NOTHING);
    if(err) {
        WHEREAMI();
        fprintf(stderr, "Something went wrong initialising libcurl (error %u)\n", err);
        exit(err);
    }

    CURL* handle = curl_easy_init();
    if(handle == NULL) {
        WHEREAMI();
        fprintf(stderr, "Something went wrong initialising curl session.\n");
        err = 1;
        goto easy_cleanup;
    }

    char errbuf[CURL_ERROR_SIZE] = { 0 };
    err = curl_easy_setopt(handle, CURLOPT_ERRORBUFFER, errbuf);
    if(err) {
        WHEREAMI();
        fprintf(stderr, "Something went wrong preparing error buffer (error %u)\n", err);
        fprintf(stderr, "Current contents of buffer:\n%s\n", errbuf);
        goto easy_cleanup;
    }
    err = curl_easy_setopt(handle, CURLOPT_URL, url);
    if(err) {
        WHEREAMI();
        fprintf(stderr, "Error %u: %s\n", err, errbuf);
        goto easy_cleanup;
    }

    if(token_cache.data[0] == '\0') {
        get_token();
        if(token_cache.data[0] == '\0') {
            WHEREAMI();
            fprintf(stderr, "Error retrieving token\n");
        }
    }
    char token_header[512] = { 0 };
    strncpy(token_header,  "X-Auth-Token: ", 64);
    strncat(token_header, token_cache.data, 256);

    struct curl_slist *H = NULL;
    H = curl_slist_append(H, token_header);
    if(H == NULL) {
        WHEREAMI();
        fprintf(stderr, "Something went wrong setting token request header\n");
        goto easy_cleanup;
    }
    err = curl_easy_setopt(handle, CURLOPT_HTTPHEADER, H);
    if(err) {
        WHEREAMI();
        fprintf(stderr, "Error %u: %s\n", err, errbuf);
        goto easy_cleanup;
    }

    err = curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, string_stuffer);
    if(err) {
        WHEREAMI();
        fprintf(stderr, "Error %u: %s\n", err, errbuf);
        goto easy_cleanup;
    }
    init_string(s);
    err = curl_easy_setopt(handle, CURLOPT_WRITEDATA, s);
    if(err) {
        WHEREAMI();
        fprintf(stderr, "Error %u: %s\n", err, errbuf);
        goto easy_cleanup;
    }

    err = curl_easy_perform(handle);
    if(err) {
        WHEREAMI();
        fprintf(stderr, "Error %u: %s\n", err, errbuf);
        goto easy_cleanup;
    }
    s->ptr[s->len] = '\0';

easy_cleanup:
    if(H != NULL) {
        curl_slist_free_all(H);
    }
    if(handle != NULL) {
        curl_easy_cleanup(handle);
    }
    curl_global_cleanup();
    return err;
}